Bhagya

Students can download 10th Social Science History Chapter 7 Anti-Colonial Movements and the British of Nationalism Questions and Answers, Notes, Samacheer Kalvi 10th Social Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Social Science Solutions History Chapter 7 Anti-Colonial Movements and the British of Nationalism

Samacheer Kalvi 10th Social Science Anti-Colonial Movements and the British of Nationalism Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
Which one of the following was launched by Haji Shariatullah in 1818 in East Bengal?
(a) Wahhabi Rebellion
(b) Farazi Movement
(c) Tribal uprising
(d) Kol Revolt
Answer:
(b) Farazi Movement

Question 2.
‘Who declared that “Land belongs to God” and collecting rent or tax on it was against divine law?
(a) Titu Mir
(b) Sidhu
(c) Dudu Mian
(d) Shariatullah
Answer:
(c) Dudu Mian

Question 3.
Who were driven out of their homeland during the process of creation of Zamins under Permanent Settlement?
(a) Santhals
(b) Titu Mir
(c) Munda
(d) Kol
Answer:
(a) Santhals

Question 4.
Find out the militant nationalist from the following.
(a) Dadabhai Naoroji
(b) Justice Govind Ranade
(c) Bipin Chandra Pal
(d) Romesh Chandra
Answer:
(c) Bipin Chandra Pal

Question 5.
When did the Partition of Bengal come into effect?
(a) 19 June 1905
(b) 18 July 1906
(c) 19 August 1907
(d) 16 October 1905
Answer:
(a) 19 June 1905

Question 6.
What was the context in which the Chotanagpur Tenancy Act was passed?
(a) Kol Revolt
(b) Indigo Revolt
(c) Munda Rebellion
(d) Deccan Riots
Answer:
(c) Munda Rebellion

Question 7.
Who set up the first Home Rule League in April 1916?
(a) Annie Basant
(b) Bipin Chandra Pal
(c) Lala Lajpat Rai
(d) Tilak
Answer:
(d) Tilak

Question 8.
Who drew the attention of the British to the suffering of Indigo cultivation through his play Nil darpanl
(a) Dina Bandhu Mitra
(b) Romesh Chandra Dutt
(c) Dadabhai Naoroji
(d) Birsa Munda
Answer:
(a) Dina Bandhu Mitra

II. Fill in the blanks

1. In 1757, Robert Clive was financially supported by ……………….. the moneylenders of Bengal.
2. ……………….. was an anti-imperial and anti-landlord movement which originated in and around 1827.
3. The major tribal revolt which took place in Chotanagpur region was ………………..
4. The ……………….. Act, restricted the entry of non-tribal people into the tribal land.
5. Around 1854 activities of social banditry were led by ………………..
6. The British Commander of Kanpur killed by the rebels during the 1857 Rebellion was ………………..
7. Chota Nagpur Act was passed in the year ………………..
8. W.C. Bannerjee was elected the president of Indian National Congress in the year ………………..

Answers:

1. Jagat Seth
2. The Wahhabi rebellion
3. Kol revolt
4. Chota Nagpur Tenancy
5. Birsingh
6. Major General Hugh Wheeler
7. 1908
8. 1885

III. Choose the correct statement

Question 1.
(i) The Company received ₹ 22.5 million from Mir Jafar and invested it to propel the industrial revolution in Britain.
(ii) Kols organized an insurrection in 1831-1832, which was directed against government officers and moneylenders.
(iii) In 1855, two Santhal brothers, Sidhu and Kanu, ledtheSanthal Rebellion.
(iv) In 1879, an Act was passed to regulate the territories occupied by the Santhals.
(a) (i), (ii) and (iii) are correct
(b) (ii) and (iii) are correct
(c) (iii) and (iv) are correct
(d) (i) and (iv) are correct
Answer:
(a) (i), (ii) and (iii) are correct

Question 2.
(i) Dudu Mian laid emphasis on the egalitarian nature of Islam and declared that “Land belongs to God”.
(ii) According to the Doctrine of Lapse, new territories under the corrupt Indian rulers were to be annexed.
(iii) The British officials after the suppression of 1857 Revolt were given power to judge and take the lives of Indians without due process of law.
(iv) One of the causes of the failure of the Revolt of 1857 was many of the Indjan princes and zamindars remained loyal to the British.
(a) (ii), (iii) and (iv) are correct
(b) (i), (ii) and (iv) are correct
(c) (i), (iii) and are correct
(d) (i), (ii) and (iii) are correct
Answer:
(c) (i), (iii) and are correct

Question 3.
(i) One of the most significant contributions of the early Indian Nationalists was the formulation of an economic critique of colonialism.
(ii) The early Congress leaders stated that religious exploitation in India was the primary reason for the growing poverty.
(iii) One of the goals of the moderate Congress leaders was to achieve Swaraj or self-rule.
(iv) The objective of the Partition of Bengal was to curtail the Bengali influence and weaken the nationalist movement.
(a) (i) and (iii) are correct
(b) (i), (iii), and (iv) are correct
(c) (ii) and (iii) are correct
(d) (iii) and (iv) are correct
Answer:
(b) (i), (iii), and (iv) are correct

Question 4.
Assertion (A): Under colonial rule, for the first time in Indian history, government claimed a direct proprietary right over forests.
Reason (R): Planters used intimidation and violence to compel farmers to grow indigo.
(a) Both A and R are correct, but R is not the correct explanation of A
(b) Both A and R are wrong
(c) Both A and R are correct and R is the correct explanation of A
(d) A is wrong and R is correct.
Answer:
(b) Both A and R are wrong

Question 5.
Assertion (A): The Revolt of 1857 was brutally suppressed by the British army.
Reason (R): The failure of the rebellion was due to the absence of Central authority.
(a) Both A and R are wrong
(b) A is wrong and R is correct
(c) Both A and R are correct and R is the correct explanation of A
(d) Both A and R are correct, but R is not the correct explanation of A
Answer:
(c) Both A and R are correct and R is the correct explanation of A

IV. Match the following

Answer:
A. (iii)
B. (iv)
C. (i)
D. (v)
E. (ii)

V. Answer the following questions briefly

Question 1.
How are the peasant uprisings in British India classified?
Answer:
There were nearly a hundred peasant uprisings during British rule. They can be classified into the following categories –

• Restorative rebellions
• Religious movements
• Social Banditry
• Mass insurrection

Question 2.
Write about the Kanpur Massacre of 1857.
Answer:

1. The seige of Kanpur was an important episode in the 1857 Rebellion.
2. The rebel forces under Nana Sahib besieged the Company forces and civilians in Kanpur.
3. They were unprepared for the extended besiege.
4. It forced them to surrender to the rebel forces under Nana Sahib, in return for a safe passage to Allahabad.
5. The boats in which they were proceeding were burned and most of them were killed including Major General Hugh Wheeler the British Commander of Kanpur.

Question 3.
Name the territories annexed by the British under the Doctrine of Lapse.
Answer:
Satara, Sambalpur, parts of Punjab, Jhansi and Nagpur.

Question 4.
What do you mean by drain of wealth?
Answer:
India was economically subjugated and transformed into a supplier of raw materials. It became a market to dump English manufactures and for the investment of British Capital. So the colonial economy was a continuous transfer of resources from India to Britain without any favourable returns back to India. This is referred as “the drain of wealth”.

Question 5.
Explain the concept of constructive swadeshi?
Answer:
Under Constructive Swadeshi, the self-defeating modest approach of moderates was rejected and self-help was focused on through swadeshi industries, national schools, arbitration courts and constructive programmes in the village. It was totally non-political in nature.

Question 6.
Highlight the objectives of Home Rule Movement.
Answer:
Objectives of the Home Rule Movement:

1. To attain self Government within the British empire by constitutional means.
2. To obtain the status of dominion a political position.
3. To use non-violence constitutional methods to achieve their goals.

Question 7.
Summarise the essence of Lucknow Pact.
Answer:
In the Lucknow Pact that took place in 1916, the Congress Party and the Muslim League agreed that there should be self-government in India as soon as possible. In return of this gesture from the Muslim League, the congress leadership accepted the concept of separate electorate for Muslims. This created a new sense of enthusiasm among the people.

VI. Answer all the questions under each caption

Question 1.
Deccan riots

(a) When and where did the first recorded incident of rioting against the moneylenders in the Deccan appear?
Answer:
In May 1875 in Supa, a village near Poona the first recorded incident of rioting against the moneylenders in the Deccan appeared.

(b) What was the right given to moneylenders under a new law of the British?
Answer:
Under the new law of the British the moneylenders were given the right to attach the mortgaged land of the defaulters auction it off.

(c) What did it result in?
Answer:
It resulted in the transfer of land from the cultivators to the non-cultivating classes.

(d) Against whom was the violence directed in the Deccan riots.
Answer:
In the Deccan riots violence was directed against the Gujarat money lenders.

Question 2.
The Revolt of 1857
(a) Who assaulted his officer, an incident that led to the outbreak of 1857 Revolt?
Answer:
Mangal Pandey assaulted his officer.

(b) Who was proclaimed the Shahenshah-e-Hindustan in Delhi?
Answer:
The Mughal Emperor Bahadur Shah II was proclaimed the Shahenshah-e-Hindustan in Delhi.

(c) Who was the correspondent of London Times to report on the brutality of the 1857 revolt?
Answer:
The correspondent’s name was William Howard Russell.

(d) What did the Queen’s proclamation say on matters relating to religion?
Answer:
The Queen proclaimed to the Indian people that the British government would not interfere in traditional institutions and religious matters.

Question 3.
Indian National Congress

(a) What were the techniques adopted by the Congress to get its grievances redressed ?
Answer:
The congress to get its grievances redressed adopted the techniques by way of appeals petitions and delegations.

(b) What do you know of Lal-Bal-Pal triumvirate?
Answer:
Lala Lajpat Rai of Punjab, Bal Gangadara Tilak of Maharashtra and Bipin Chandra Pal of Bengal called as Lai – Bal – Pal.
Lai – Bal – Pal triumvirate were the prominent Congress leaders of militiant nationalists.

(c) Where was the first session of Indian National Congress held?
Answer:
The first session of Indian National Congress was held at Bombay.

(d) How did the British respond to the Swadeshi Movement?
Answer:
The British brutally crushed the Swadeshi Movement. Revolutionaries were hanged. Press was crushed and prominent leaders were arrested and imprisoned for long terms.

VII. Answer in detail

Question 1.
Discuss the causes and consequences of the Revolt of 1857?
Answer:
The Great Rebellion of 1857 is a unique example of resistance to the British authorities, in India. There were several reasons that triggered the Revolt:
(i) The annexation policy of British India created dissatisfaction among the native rulers. The British claimed themselves as paramount, exercising supreme authority. New territories were annexed on the grounds that the native rulers were corrupt, and inept.

(ii) The British annexed several territories such as Satara, Sambalpur, parts of Punjab, Jhansi and Nagpur through the Doctrine of Lapse. This also angered many Indian rulers.

(iii) Indian sepoys were upset with discrimination in salary’ and promotion. They were paid much less than their European counterparts. They felt humiliated and racially abused by their seniors.

Consequences:
(i) India was pronounced as one of the many crown colonies to be directly governed by the Parliament. This resulted in the transfer of power from the East India company to the British crown.

(ii) Queen Victoria proclaimed to the Indian people that the British government would not interfere in traditional institutions and religious matters. It was promised that Indians would be absorbed in government services.

(iii) There came significant changes in the Indian army. The number of Indians was reduced.
Indians were restrained from holding important ranks and position.

(iv) It was also decided that instead of recruiting soldiers from Rajputs, Brahmins and North Indian Muslims, more soldiers would be recruited from the Gorkhas, Sikhs and Pathans.

Question 2.
How did the people of Bengal respond to the Partition of Bengal (1905)?
Answer:

1. In 1899 Lord Curzon was appointed as the Viceroy of India.
2. Curzon resorted to repressive measures to undermine the idea of local Government, autonomy of higher educational Institutions and gag the press.
3. The idea of partition was planned to suppress the political activities against the British rule in Bengal by creating a Hindu-Muslim divide.
4. It was openly stated that the main notion of partition was to curtail Bengali mfluence and to weaken the nationalist movement.
5. Bengal was Partitioned into two units Bengali Hindus (West Bengal) and Muslims (East Bengal).
6. Partition of Bengal in 1905 led to widespread protests all across India, starting a new phase of the Indian National movement.
7. The partition instead of dividing, united the people of Bengal.
8. People marched on the streets of Calcutta in thousands singing Bande mataram.
9. The partition led to the Boycott of the British goods and Swadeshi movement.

Question 3.
Attempt a narrative account of how Tilak and Annie Besant by launching Home Rule Movement sustained the Indian freedom struggle after 1916?
Answer:
(i) The Indian National Movement was revived and also radicalised during the Home Rule , League Movement that lasted from 1915 to 1918. It was led by Lokamanya Tilak and Annie Besant.

(ii) The objective of the Home Rule Movement was to attain self-government within the British Empire.

(iii) Tilak set up the first Home Rule League in April 1916. In September 1916, after repeated demands of her followers, Annie Besant decided to start the Home Rule League without the support of the Congress. Both the Leagues worked independently.

(iv) The Home Rule Leagues were utilised to carry extensive propaganda through press, speeches, public meetings, lectures, discussions and touring in favour of self government.

(v) Both the leagues succeeded in enrolling young people in large numbers and extending the movement to the rural areas.

VIII. Activity

Question 1.
Identify the Acts passed in British India from 1858 to 1919, with a brief note on each.
Answer:
Government of India Act (1858):

1. It was passed to end the rule of the East India Company and transfer the power to the British Crown.
2. The British Governor General Post was designated as viceroy of India, who became the representative of the British Monarch.

Indian Council Act – 1892:

1. The British Parliament introduced various amendments to the composition and functions of legislative council, increased the number of additional members to be represented both in central and provinces.
2. The members were given the right to ask questions on budget.
3. This Act laid the foundation of parliamentary system in India.
4. It is a landmark in the constitutional development.

Indian Council Act of 1909:

1. Popularly known as Minto – Morley Reforms.
2. This Act directly introduced the elective principle to membership in the imperial and local legislative councils.
3. It increased the involvement of Indians limitedly in the British Governance.

Montagu – Chelmsford Reform (1919):

1. The British Parliament passed this Act to expand participation of Indians in the division of executive branch of each provincial Government in to authoritarian and popularly responsible section for the provinces of British India.
2. Embodied reforms recommended in the report of the secretary of state of India.
3. This Act promised gradual progress of India towards self – Government.

Dy Archy (1919):

1. This Act introduced dual Government for the provinces of British India. One is accountable and the other one non accountable.
2. It marked the 1st introduction of democratic principle into the executive branch of British administration.
3. It was the association of Indians with the legislation work.
4. Introduced Port – folio system.

Question 2.
Mark the important centres of 1857 Revolt on an outline map.
Answer:

Question 3.
Prepare an album with pictures of frontline leaders of all the anti-colonial struggles launched against the British.
Answer:
Pictures of Moderates

Tribal Rebellion and other movement

Samacheer Kalvi 10th Social Science Anti-Colonial Movements and the British of Nationalism Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
The Nawab of Bengal ……………….. was defeated by the East India company at the Battle of Plassey.
(a) Shuja-ud-daullah
(b) Siraj-ud-daullah
(c) Mirjafar
(d) Mir Kasim
Answer:
(b) Siraj-ud-daullah

Question 2.
Indian Historians describes the revolt of 1857 as ……………….
(a) Sepoy mutiny
(b) First war of Indian Independence
(c) Military revolt
Answer:
(b) First war of Indian Independence

Question 3.
The collective farming of the tribals of Ranchi was known as:
(a) Jhum
(b) Bethbegari
(c) Khunkatti
(d) Ryotwari
Answer:
(c) Khunkatti

Question 4.
The peasants had to pay heavy …………….
(a) land taxes
(b) tariffs
(c) service taxes
Answer:
(a) land taxes

Question 5.
The ……………….. had leased out to moneylenders the job of revenue collection.
(a) Raja of Chota Nagpur
(b) European officers
(c) Nawab of Bengal
(d) Birsaite Raj
Answer:
(a) Raja of Chota Nagpur

Question 6.
The sepoys broke into open revolt at …………..
(a) Meerut
(b) Kanpur
(c) Barrackpore
Answer:
(a) Meerut

Question 7.
On ……………….. a band of sepoys from Meerut marched to the Red Fort in Delhi.
(a) 1^st May 1858
(b) 11^th May 1852
(c) 11^th May 1857
(d) 19^th September 1916
Answer:
(c) 11^th May 1857

Question 8.
After the  1857 revolt the Governor-General of India was designated as …………….
(a) Viceroy of India
(b) Ruler of India
(c) Minister of India
Answer:
(a) Viceroy of India

Question 9.
……………….. led the Revolt at Bareilly.
(a) Bahadur Shah – II
(b) Khan Bahadur
(c) Nana Sahib
(d) Kunwar Singh
Answer:
(b) Khan Bahadur

Question 10.
Rani Lakshmi Bai led the revolt at …………….
(a) Kanpur
(b) Central India
(c) Lucknow
Answer:
(b) Central India

Question 11.
The play “Nil Darpan” by ……………….. did much to draw attention in India and Europe to the plight of the indigo growers.
(a) Dina Bandhu mitra
(b) Bankim Chandra Chatterjee
(c) Lockmanya Tilak
(d) Ranajit Guha
Answer:
(a) Dina Bandhu mitra

Question 12.
In 1858, the Royal Durbar was held at …………..
(a) Meerut
(b) Allahabad
(c) Delhi
Answer:
(b) Allahabad

Question 13.
The Madras Native Association was formed in the year:
(a) 1806
(b) 1852
(c) 1884
(d) 1852
Answer:
(b) 1852

Question 14.
Which one was not a trading company?
(a) The Portuguese
(b) The French
(c) The Japanese
Answer:
(c) The Japanese

Question 15.
……………….. lent his services to facilitate the formation of Indian National Congress.
(a) A.O.Hume
(b) W.C.Baneijee
(c) Mrs. Annie Besant
(d) V.O.Chidambarampillai
Answer:
(a) A.O.Hume

II. Fill in the blanks

1. The ………………….. helped to unite the Congress party after the Surat split.
2. The ………………….. movement enhanced to participation of masses in Nationalist Politics.
3. The British mainly responded to political activities of nationalists by repression and …………………..
4. The Indian National Movement was revived and ………………….. during the Home Rule movement.
5. ………………….. launched the Swadeshi Steam Navigation Company in Tuticorin.
6. One of the common goals of the extremist leaders was to achieve …………………..
7. For ………………….. Swaraj was the attainment of complete autonomy and total freedom from foreign rule.
8. ………………….. decided to started the Home Rule League without the support of the Congress.
9. The Home Rule Movement in India borrowed much of its principles from the …………………..
10. In the ………………….. session of Indian National Congress (1916) decided to admit the militant faction in to the party.
11. Pherozeshah Metha and Gokhale two main voices of opposition against militant faction had died in …………………..
12. Bengal was officially partitioned on ………………….. by Lord Curzon.
13. The official declaration of partition of Bengal was observed as a day of …………………..
14. In a divided Bengal Curzen made the Bengali speaking people to a …………………..
15. In the year 1899 ………………….. was appointed as the viceroy of India.
16. Early Indian Nationalists advocated …………………..
17. The formation of the ………………….. in 1885 was intended to establish an All India Organisation.
18. The early leaders felt that ………………….. was the main obstacle to the India’s Economic Development.
19. One of the key demand of the Indian National Congress was creation of ………………….. at provincial and central level.
20. ………………….. played a significant role in propagating the ideas of Nationalism.
21. Under British rule peasants were forced to pay revenue directly to the …………………..
22. Vicious cycle of debt forced the peasants to abandon ………………….. in 1875.
23. The British planters forced the cultivators to grow ………………….. rather than food crops.
24. ………………….. was appointed by the British Parliament to look into the Indian affairs after 1857 revolt.
25. In November 1858 the power to govern India was transferred from ………………….. to the British Crown.
26. The ………………….. was an important episode in the rebellion of 1857.
27. The Kingdom of Jhansi was annexed under …………………..
28. De throning of many Indian rulers affected the livelihood of ………………….. due to lose of patronage.
29. ………………….. of the people against the British took the form of a people’s revolt.
30. Thousands of weavers were thrown out of employment due to the dumping of …………………..
31. By the beginning of June 1857 except ………………….. and ………………….. British Rule in North India had disappeared because of the mutineers.
32. The precursor to the revolt was the introduction of new ………………….. of the Enfiled Rifles.
33. The ………………….. claimed themselves as paramount power.
34. The ………………….. was the first major revolt of armed forces accompanied by civilian rebellion.
35. In the 1890’s ………………….. offered resistance against the alienation of tribal people from their land.
36. The ………………….. prompted the British to formulate a policy on Tribal land.
37. The Munda people were forcefully recruited as ………………….. to work on plantations.
38. The Munda rebellion movement received an impetus when ………………….. declared himself as the messenger of God.
39. The disillusionment with ………………….. aggravated the miseries of Munda people.
40. One of the prominent tribal rebellion in Ranchi was known as …………………..
41. After the battle of ………………….. the British adopted a policy of territorial expansion.
42. The British ………………….. was rapidly mechanized with the money received by the company from Mir Jafar.
43. India was led to the path of because of Britsh manufactured goods.
44. ………………….. was forced to create a market for the products from Britain.
45. The plunder of India by the ………………….. continued for nearly 190 years.
46. There were nearly a hundred ………………….. during the British rule.
47. The leaders of ………………….. movements were looked upon by their people as heroes of their cause.
48. The ………………….. are usually leaderless and spontaneous uprising.
49. The subletting of land by the zamindars increased the ………………….. on the peasants.
50. Wahhabi Rebellion originated in 1827 in and around ………………….. of Bengal.

Answer:

1. Home Ruler Movement
2. Swadeshi
3. Reconciliation
4. Radicaliszed
5. V.O.Chidambaranar
6. Swaraj or Self Rule
7. Tilak
8. Mrs. Annie Besant
9. Irish Home Rule Movement
10. Lucknow session
11. 1915
12. 16^th October 1905
13. Mourning
14. Linguistic minority
15. Lord Curzon
16. Industrialisation
17. Indian National Congress
18. Colonialism
19. Legislative councils
20. Print media
21. Government
22. agriculture
23. Indigo plant
24. Secretary of State
25. English East India Company
26. Seige of Kanpur
27. Doctrine of Lapse
28. Artisans and handicrafts persons
29. Collective anger
30. British manufacture
31. Punjab and Bengal
32. greased cartridges
33. British
34. Great Rebellion of 1857
35. Tribal chiefs
36. Munda rebellion
37. Indentured labourers
38. Birsa Munda
39. Christian missionaries
40. Ulugalan rebellion
41. Plassey
42. Textile industry
43. De. industrialisation
44. India
45. East India company
46. Peasant uprisings
47. Social banditry
48. Mass insurrection
49. Tax burden
50. Barasat

III. Choose the correct statement

Question 1.
(i) The urban elite of India was busy responding to the western ideas through socio – religious reform movements.
(ii) The traditional elite and peasantry wanted to restore pre – colonial order by revolts.
(iii) The practice of letting out and subletting of land complicated the industrial relations.
(iv) Changes introduced in the land tenures significantly altered the agrarian relations.
(a) (i), (ii) and (iv) are correct
(b) (i), (ii) and (iii) are correct
(c) (i), (iii) and (iv) are correct
(d) (ii), (iii) and (iv) are correct
Answer:
(a) (i), (ii) and (iv) are correct

Question 2.
(i) The commercialisation of forest led to the disintegration of the traditional tribal system.
(ii) The usury and forcible eviction of tribals from their land led to the resentment of kols.
(iii) The pushed out santhals were forced to rely on the moneylenders for their subsistence.
(iv) Santhals felt secured under the British.
(a) (i), (ii) and (iv) are correct
(b) (i), (iii) and (iv) are correct
(c) (i), (ii)-and(iii) are correct
(d) (ii), (iii) and (iv) are correct
Answer:
(c) (i), (ii)-and(iii) are correct

Question 3.
(i) The British annexed more territories through two major policies.
(ii) Indian sepoys accepted the new dress code and overseas service.
(iii) Before loading into Enfiled Rifle the cartridges had to be bitten off.
(iv) The Indian Sepoys felt humiliated and racially abused by their seniors.
(a) (i) and (iii) are correct
(b) (i), (ii) and (iii) are correct
(c) (i), (ii) and (iv) are correct
(d) (i), (iii) and (iv) are correct
Answer:
(d) (i), (iii) and (iv) are correct

Question 4.
Assertion (A): The mutiny was equally supported by an aggrieved rural society of North India.
Reason (R): Sepoys working in British army were infact peasants in uniform.
(a) Both A and R are wrong.
(b) Both A and R are correct and R is the correct explanation of A.
(c) A is correct R is wrong.
(d) Both A and R are correct but R is the not the correct explanation of A.
Answer:
(b) Both A and R are correct and R is the correct explanation of A.

Question 5.
Assertion (A): India extended its support to the British in world war I. Reason (R): Hoping for the attainment of self – Government after the war.
(a) A is correct R is wrong.
(b) Both A and R are wrong.
(c) Both A and R are correct but R is not the correct explanation of A.
(d) Both A and R are correct and R is the correct explanation of A.
Answer:
(d) Both A and R are correct and R is the correct explanation of A.

IV. Match the following

Question 1.
Match the Column I with Column II.

Answer:
A. (iii)
B. (v)
C. (iv)
D. (i)
E. (ii)

Question 2.
Match the Column I with Column II.

Answer:
A. (ii)
B. (v)
C. (iv)
D. (i)
E. (ii)

Question 3.
Match the Column I with Column II.

Answer:
A. (ii)
B. (v)
C. (i)
D. (iii)
E. (vi)
F. (vii)

V. Answer the following question briefly

Question 1.
What caused huge loss of revenue in Bengal?
Answer:
Aurangzeb’s farman had granted the company only the right to trade duty free. But the officials of the company, who were carrying on private trade on side also stopped paying duty. This caused a huge loss of revenue for Bengal.

Question 2.
Mention some of the issues of peasants that added to the sense of resentment against the British.
Answer:

1. The concept of private property rights in land.
2. Rigorous collection of land revenue.
3. Encroachment of tribal land by non-tribal people.
4. Interference of Christian Missionaries in the socio – religious life of the local people.

Were some of the issues of resentment against the British.

Question 3.
Why did the Battle of Plassey become famous?
Answer:
It was the first major victory the company won in India.

Question 4.
What were the reasons for Tribal upraising?
Answer:

1. Under colonial rule the Government claimed a direct proprietary right over forests.
2. The commercialisation of forests led to the disintegration of the traditional tribal system.
3. It encouraged the incursion of tribal areas by non-tribal people such as contractors, moneylenders traders, land grabbers.
4. This led to the wide spread loss of adivasi land and their displacement from their traditional habitats. So Tribal resistance arose.

Question 5.
What were the grievances of the company regarding the Nawabs of Bengal?
Answer:
The company declared that the unjust demands of the local officials were ruining the trade of the company. Trade could flourish only if the duties were removed. It was also convinced to expand trade, it had to enlarge its settlements, buy up villages and rebuild its forts.

Question 6.
Name the early leaders who criticized about colonial economy.
Answer:
Dadabhai Naoroji, Justice Ranade and Romesh Chandra Dutt strongly criticised about the colonial economy.

They clearly stated that the prosperity of the British lay in the economic and political subjugation of India.

They concluded that the colonialism was the main obstacle to the India’s economic development.

Question 7.
Which battle did Robert Clive fight in 1757 and against whom?
Answer:
In 1757, he fought the Battle of Plassey against Siraj-ud-daulah.

VI. Answer all the questions under each caption

Question 1.
Political causes for the Revolt of 1857.

(a) Who introduced subsidiary Alliance?
Answer:
Lord Wellesley introduced subsidiary Alliance.

(b) Name the policy introduced by Lord Balhousie.
Answer:
Lord Dalhousie introduced the policy of “Doctrine of Lapse”.

(c) What was the order issued by the British against the Mughal emperor?
Answer:
The British Government had ordered that the Mughal emperor had to give up their ancestral palace and Red fort.

(d) Why did Nana Saheb develop a grudge against the British.
Answer:
The British stopped the pension to Nana Saheb. So he developed a grudge against the British.

Question 2.
Great Rebellion of 1857

(a) What was the biggest challenge witnessed by the British in 1857?
Answer:
The Great Rebellion by the Sepoys and the civilians.

(b) What was witnessed by both sides during the revolt?
Answer:
Unprecedented violence

(c) What were the causes of the revolt?
Answer:

1. Annexation policy of the British in India.
2. Insensitivity of the British to Indian cultural sentiments.

(d) What was the people’s opinion on the new regulations of the British.
Answer:
There was always a suspicion among the people regarding British new regulations intention.

Question 3.
Wahhabi Rebellion in Barasat

(a) Who led the Wahhabi Rebellion? Write a few lines about him.
Answer:
Titu Mir, an Islamic preacher led this rebellion. He was deeply influenced by the Wahhabi teachings. He became an important figure among the predominantly Muslim peasantry oppressed under the zamindari system.

(b) How did this movement acquire an anti-Hindu complexion?
Answer:
The majority of zamindars were Hindus. Thus, the movement acquired an anti-Hindu complexion.

(c) what happened on 6 November 1831?
Answer:
On 6 November 1831, the first major attack was made in the town of Pumea. Titu Mir immediately declared freedom from British Rule.

(d) How did the British respond to this rebellion?
Answer:
The British sent a large number of Troops to Narkelberia. Titu Mir along with his soldiers were killed in the staiggle.

Question 4.
Peasant and Tribal Resistance

(a) What was the nature of the resistance against the British rule emerged in rural India?
Answer:
More aggressive response emerged in rural India.

(b) Who revolted against the British in rural areas?
Answer:
Traditional elite and peasants along with tribals revolted.

(c) What did they seek for?
Answer:
They sought for the restoration of the Pre-colonial order and not the removal of the British.

(d) What was the outlook of the tribals on British?
Answer:
The tribal people started looking at the British as invaders and encroachers.

VII. Answer in detail

Question 1.
Enumerate the cause for the failure of the Great Revolt of 1857.
Answer:
Administrative changes:

1. Disunity among the Indians was the first and the foremost cause.
2. A large number of rulers of the Indian states and the big zamindars did not join the movement,
3. The rulers of the Indian states, who did not support the movement, remained neutral.
4. The educated Indians did not support the movement.
5. The telegraph and postal communication proved very helpful to the British for proper military actions and sending their reinforcements at the earliest time.
6. The rebellious soldiers were short of modem weapons and other materials of war.
7. The rebellious soldiers had to fight with traditional weapons which were no match to modem weapons possessed by the British forces.
8. The revolt was not extended beyond North.
9. The Indian leaders like Nana Saheb, Tantia Tope, Rani Lakshmi Bai where no match to the British generals.
10. The revolt broke out prematurely and the preparations for the revolt remained incomplete.
11. The organization and the planning of the rebels was very poor.
12. The Indian leaders were brave and selfless but they lacked unity of command and discipline.
13. The revolutionaries had no common idea.
14. The Muslims wanted to revive Mughal rule and the Hindus wanted to receive the Peshwa Raj.
15. The British diplomacy of Divide and Rule prevented most of the Indian mlers to join together for a common cause.

Question 2.
What was the objective of the partition of Bengal (1905) and what was its result?
Answer:

1. The main objective of partition of Bengal was to divide the Hindu – Muslim unity and to influence and weaken the nationalist movement.
2. Bengal was partitioned into two administrative units.
3. Reduced the Bengali – speaking people to a linguistic minority in a divided Bengal.
4. Curzon assured Muslims that in the new province of East Bengal Muslim would enjoy a unity.

Result:

1. Curzon thought the partition would divide the Bengali people on religious line.
2. Instead the partition united the people of Bengal.
3. The growth of the vernacular newspapers played a vital role in building a sense of proud Bengali identity.
4. The day Bengal was officially partitioned (16th Oct 1905) was declared as a day of mourning.
5. Thousands of people took bath in Ganga and marched on the streets of Calcutta singing Bande Mataram.

Question 3.
Throw light on the Farazi Movement.
OR
Highlight the different phases of the Farazi Movement under Haji Shariatullah and his son Dudu Mia.
Answer:
Farazi Movement under Haji Shariatullah:
The Farazi Movement was launched by Haji Shariatullah in 1818, in the parts of eastern Bengal. The movement advocated the participants to keep themselves away from conflict with the zamindars and subsequently with the British, who favoured the zamindars to suppress the peasant uprising.

Farazi Movement under Dudu Mian:
After the death of Shariatullah in 1839, the movement was led by his son Dudu Mian. He called upon the peasant not to pay tax. The movement became popular on a simple doctrine that land and all wealth should be equally enjoyed by the common mass. Dudu Mian laid emphasis on the egalitarian nature of religion and declared that “Land belongs to God’’ and collecting rent or levying taxes on it was therefore against the divine law. The movement spread far and wide and was joined by a huge number of peasants. There were violent crashes throughout 1840s and 1850s with the zamidars and planters. The movement continued to resist even after the death of Dudu Mian in 1862.

Question 4.
What were the main objectives and key demands of Indian National Congress?
Answer:
The main objectives of Indian National Congress were to develop and consolidate the sentiments of national unity and loyalty to Britain.

Some of the key demands were:

1. Creation of legislative councils at provincial and central level.
2. Reducing military expenditure.
3. Holding civil services exams in India as well as in England.
4. Promotion of Indian industries and an end to unfair tariffs and an end to unfair tariffs and excise duties.
5. Extension of trial by jury.
6. Increasing the number of elected members in the legislative council.
7. Police reforms
8. Reduction of Home charges.
9. Reconsideration of forest laws.
10. Separating Judicial and executive functions.

Students can download 10th Science Chapter 4 Electricity Questions and Answers, Notes, Samacheer Kalvi 10th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 4 Electricity

Samacheer Kalvi 10th Science Electricity Text Book Back Questions and Answers

I. Choose the best answer.

Question 1.
Which of the following is correct?
(a) Rate of change of charge is electrical power.
(b) Rate of change of charge is current.
(c) Rate of change of energy is current.
(d) Rate of change of current is charge.
Answer:
(b) Rate of change of charge is current.

Question 2.
SI unit of resistance is:
(a) mho
(b) joule
(c) ohm
(d) ohm meter
Answer:
(c) ohm

Question 3.
In a simple circuit, why does the bulb glow when you close the switch?
(a) The switch produces electricity.
(b) Closing the switch completes the circuit.
(c) Closing the switch breaks the circuit.
(d) The bulb is getting charged.
Answer:
(b) Closing the switch completes the circuit

Question 4.
Kilowatt hour is the unit of:
(a) resistivity
(b) conductivity
(c) electrical energy
(d) electrical power
Answer:
(c) electrical energy

II. Fill in the blanks.

1. When a circuit is open, ……….. cannot pass through it.
2. The ratio of the potential difference to the current is known as ……….
3. The wiring in a house consists of ………… circuits.
4. The power of an electric device is a product of ……… and ………..
5. LED stands for ………..

Answer:

1. current
2. resistance
3. parallel
4. potential difference, current
5. Light Emitting Diode

III. State whether the following statements are true or false: If false correct the statement.

1. Ohm’s law states the relationship between power and voltage.
2. MCB is used to protect house hold electrical appliances.
3. The SI unit for electric current is the coulomb.
4. One unit of electrical energy consumed is equal to 1000 kilowatt hour.
5. The effective resistance of three resistors connected in series is lesser than the lowest of the individual resistances.

Answer:

1. False – Ohm’s law states that the relationship between current and voltage.
2. True
3. False – The SI unit for electric current is ampere.
4. False – One unit of electrical energy consumed is equal to 1 kilowatt hour.
5. False – The effective resistance of three resistors connected in series is greater than the highest of the “individual resistance.

IV. Match the items in column-1 to the items in column-ll.

Answer:
(i) – (e)
(ii) – (a)
(iii) – (b)
(iv) – (c)
(v) – (d)

V. Assertion and reason type Questions.

Mark the correct choice as
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.
1. Assertion: Electric appliances with a metallic body have three wire connections.
Reason: Three pin connections reduce heating of the connecting wires.
Answer:
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.

2. Assertion: In a simple battery circuit the point of highest potential is the positive terminal of the battery.
Reason: The current flows towards the point of the highest potential.
Answer:
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.

3. Assertion: LED bulbs are far better than incandescent bulbs.
Reason: LED bulbs consume less power than incandescent bulbs.
Answer:
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.

VI. Very short answer questions.

Question 1.
Define the unit of current.
Answer:
The current flowing through a conductor is said to be one ampere, when a charge of one coulomb flows across any cross-section of a conductor, in one second. Hence,
1 ampere = \(\frac{1 coulomb}{1 second}\)

Question 2.
What happens to the resistance, as the conductor is made thicker?
Answer:
If the conductor is made a thicker area of cross-section of conduction increases that will decrease the resistance.

Question 3.
Why is tungsten metal used in bulbs, but not in fuse wires?
Answer:
Tungsten metal is used in bulbs because its melting point is the greatest.
But it is not used in fuse wires. When a current more than 5A flows tungsten wire will be melted. Hence tungsten is not used in fuse wire.

Question 4.
Name any two devices, which are working on the heating effect of the electric current.
Answer:
The heating effect of electric current is used in many home appliances such as electric iron and electric toaster.

VII. Short Answer Questions.

Question 1.
Define electric potential and potential difference.
Answer:
Electric Potential: It is the amount of work done in moving unit positive charge from infinity to that point against the electric force.
Electric potential

Potential difference : It is the amount of work done in moving a unit positive charge from one point to another against the electric force.
Potential difference V_A – V_B = \(\frac{W_{A}-W_{B}}{Q}\)

Question 2.
What is the role of the earth wire in domestic circuits?
Answer:

1. The earth wire provides a low resistance path to the electric current.
2. The earth wire sends the current from the body of the appliance to the Earth, whenever a live wire accidentally touches the body of the metallic electric appliance.
3. Thus, the earth wire serves as a protective conductor, which saves us from electric shocks.

Question 3.
State Ohm’s law.
Answer:
According to Ohm’s law, at a constant temperature, the steady current ‘I’ flowing through a conductor is directly proportional to the potential difference ‘V’ between the two ends of the conductor.
I ∝ V. Hence, = \(\frac{1}{V}\) = constant.
The value of this proportionality constant is found to \(\frac{1}{R}\)
Therefore, I = (\(\frac{1}{R}\)) V
V = IR

Question 4.
Distinguish between the resistivity and conductivity of a conductor.
Answer:

Question 5.
What connection is used in domestic appliances and why?
Answer:

1. In the domestic appliance, it is used as a parallel connection to avoid short circuit and breakage.
2. It has an alternative current (AC). Not DC current as it is from cables, so high potential flows through this.
3. One more advantage of the parallel connection of circuits is that each electric appliance gets an equal voltage.

VIII. Long answer Questions.

Question 1.
With the help of a circuit diagram derive the formula for the resultant resistance of three resistances connected:
(a) in series and
(b) in parallel
Answer:
(a) Resistors in series : A series circuit connects the components one after the other to form a ‘single loop’. A series circuit has only one loop through which current can pass. If the circuit is interrupted at any point in the loop, no current can pass through the circuit and hence no electric appliances connected in the circuit will work. Series circuits are commonly used in devices such as flashlights. Thus, if resistors are connected end to end, so that the same current passes through each of them, then they are said to be connected in series.

Let, three resistances R₁, R₂ and R₃ be connected in series. Let the current flowing through theorem be I. According to Ohm’s Law, the potential differences V₁,V₂ and V₃ across R₁, R₂ and R₃ respectively, are given by:
V₁ = I R₁ ………. (1)
V₂ = I R₂ ……… (2)
v₃ = I R₃ ………. (3)
The sum of the potential differences across the ends of each resistor is given by:
V = V₁ + V₂ + V₃
Using equations (1), (2) and (3), we get
V = I R₁ + I R₂ + I R₃ …….. (4)
The effective resistor is a single resistor, which can replace the resistors effectively, so as to allow the same current through the electric circuit. Let, the effective resistance of the series-combination of the resistors, be R_S.
Then,
V = I R_S ……….(5)
Combining equations (4) and (5), we get,
I R_S = I R₁ + I R₂ + I R₃
R_S = R₁ + R₂ + R₃ ……….. (6)
Thus, you can understand that when a number of resistors are connected in series, their equivalent resistance or effective resistance is equal to the sum of the individual resistances. When ‘n’ resistors of equal resistance R are connected in series, the equivalent resistance is ‘n R’.
i.e., R_S = n R
The equivalent resistance in a series combination is greater than the highest of the individual resistances.

(b) Resistors in Parallel : A parallel circuit has two or more loops through which current can pass. If the circuit is disconnected in one of the loops, the current can still pass through the other loop(s). The wiring in a house consists of parallel circuits.

Consider that three resistors R₁, R₂ and R₃ are connected across two common points A and B The potential difference across each resistance is the same and equal to the potential difference between A and B. This is me sured using the voltmeter. The current I arriving at A divides into three branches I₁, I₂ and I₃ passing through R₁, R₂ and R₃ respectively.
According to the Ohm’s law, you have,

The total current through the circuit is given by
I = I₁ + I₂ + I₃
Using equations (1), (2) and (3), you get
I = \(\frac{V}{R_1}\) + \(\frac{V}{R_2}\) + \(\frac{V}{R_3}\) ……… (4)
Let the effective resistance of the parallel combination of resistors be R_P Then,
I = \(\frac{V}{R_P}\) ……… (5)
Combining equations (4) and (5), you have

Thus, when a number of resistors are connected in parallel, the sum of the reciprocals of the individual resistances is equal to the reciprocal of the effective or equivalent resistance. When ‘n’ resistors of equal resistances R are connected in parallel, the equivalent resistance is \(\frac{R}{n}\)

The equivalent resistance in a parallel combination is less than the lowest of the individual resistances.

Question 2.
(a) What is meant by electric current? Give its direction?
(b) Name and define its unit.
(c) Which instrument is used to measure the electric current? How should it be r connected in a circuit?
Answer:
(a) (i) Electric current is often termed as ‘current’ and it is represented by the symbol ‘I’. It is defined as the rate of flow of charges in a conductor.
(ii) The electric current represents the number of charges flowing in any cross-section of a conductor (say a metal wire) in unit time.

(b) The SI unit of electric current is ampere (A).
The current flowing through a conductor is said to be one ampere, when a charge of one coulomb flows across any cross-section of a conductor, in one second. Hence,
1 ampere = \(\frac{1 \text { coulomb }}{1 \text { second }}\)

(c) (i) The ammeter is used to measure the current.
(ii) An Ammeter is connected in series with the circuit.
(iii) The Ammeter is a low impedance device connecting it in parallel with the circuit would cause a short circuit, damaging the Ammeter or the circuit.

Question 3.
(a) State Joule’s law of heating.
(b) An alloy of nickel and chromium is used as the heating element. Why?
(c) How does a fuse wire protect electrical appliances?
Answer:
(a) Joule’s law of heating states that the heat produced in any resistor is:

1. directly proportional to the square of the current passing through the resistor.
2. directly proportional to the resistance of the resistor.
3. directly proportional to the time for which the current is passing through the resistor.

(b) Because,

1. It has high resistivity,
2. It has a high melting point,
3. It is not easily oxidized.

(c) When a large current passes through the circuit, the fuse wire melts due to Joule’s heating effect and hence the circuit gets disconnected. Therefore, the circuit and the electric appliances are saved from any damage.

Question 4.
Explain about domestic electric circuits, (circuit diagram not required)
Answer:

1. Electricity is distributed through the domestic electric circuits wired by the electricians.
2. The first stage of the domestic circuit is to bring the power supply to the main-box from a distribution panel, such as a transformer.
3. The important components of the main-box are: (i) a fuse box and (ii) a meter. The meter is used to record the consumption of electrical energy.
4. The fuse box contains either a fuse wire or a miniature circuit breaker (MCB).
5. The function of the fuse wire or an MCB is to protect the household electrical appliances from overloading due to excess current.

Question 5.
(a) What are the advantages of LED TV over the normal TV?
(b) List the merits of LED bulb.
Answer:
(a) Advantages of LED TV:

1. It has brighter picture quality.
2. It is thinner in size.
3. It uses less power and consumes very less energy.
4. Its life span is more.
5. It is more reliable.

(b) Advantages of LED bulb:

1. As there is no filament, there is no loss of energy in the form of heat.
2. It is cooler than the incandescent bulb.
3. In comparison with the fluorescent light, the LED bulbs have significantly low power requirement.
4. It is not harmful to the environment.
5. A wide range of colours is possible here.
6. It is cost-efficient and energy efficient.
7. Mercury and other toxic materials are not required. One way of overcoming the energy crisis is to use more LED bulbs.

IX. Numerical problems.

Question 1.
An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220 V. What is the current in each case?
Answer:
(i) When heating is maximum, the power
P₁ = 420 W
Applied voltage V = 220 V
P = VI
Current I = \(\frac{P}{V}\)
I = \(\frac{420}{220}\) = 1.909 A
I = 1.909 A

(ii) When heating is minimum
Power P₂ = 180 W
Applied voltage V = 220 V
P = VI
∴ Current I = \(\frac{P}{V}\)
I = \(\frac{180}{220}\) = 0.8181 A
I = 0.8181 A

Question 2.
A 100-watt electric bulb is used for 5 hours daily and four 60 watt bulbs are used for 5 hours daily. Calculate the energy consumed (in kWh) in the month of January.
Solution:
100 W = 100 joules per second
1 watt hours = 3600 joules
The electric bulb is lighted for 5 hours daily,
100 W × 5 = 500 watt hours
500 watt hours = 1800000 joules
1 kWh = 3600000 joules
Units consumed per day = \(\frac{1800000}{3600000}\) = 0.5 units
Untis consumed in month = 0.5 × 31 = 15.5 units …. (1)
Now, Sum of power of four 60 watt bulbs = 240 W
240 W × 5 hours = 1200 watt hours
1200 watt hours = 4320000 joules
Energy consumed per day = \(\frac{4320000}{3600000}\) = 1.2 units
Energy consumed in a month = 1.2 × 31 = 37.2 units …. (2)
Total energy consumed in a month = 15.5 + 37.2 = 52.7 units
1 unit = 1 kWh
The energy consumed in the month of January = 52.7 kWh.

Question 3.
A torch bulb is rated at 3 V and 600 mA. Calculate it’s
(a) power
(b) resistance
(c) energy consumed if it is used for 4 hour.
Answer:
Voltage V = 3 V
Current I = 600 mA
(a) Power = VI
= 3 × 600 × 10^-3
= 1800 × 10^-3
= 1.8 W

(c) Time = 4h
Energy consumed E = P × t
E = 1.8 × 4
= 7.2 W

Question 4.
A piece of wire having a resistance R is cut into five equal parts.
(a) How will the resistance of each part of the wire change compared with the original resistance?
(b) If the five parts of the wire are placed in parallel, how will the resistance of the combination change?
(c) What will be ratio of the effective resistance in series connection to that of the parallel connection?
Answer:
(a) Original resistance
R = \(\frac{l}{A}\)
∴ R α l
After cutting length of each piece
r = \(\frac{l}{5}\)
New resistance
R’ = \(\frac{l’}{A}\)
R’ α l’

R : R’ = 5 : 1

(b) When five parts of the wire are placed in parallel.
Effective Resistance

Resistance of the combinations
R_P = \(\frac{R}{25}\)

(c) When resistance are connected in series

R_S = R
When resistance are connected in parallel
R_P = \(\frac{R}{25}\)
R_S : R_P = R : \(\frac{R}{25}\)
= 25 R : R_1
R_S : R_P = 25 : 1

X. HOT Questions.

Question 1.
Two resistors when connected in parallel give the resultant resistance of 2 ohm; but when connected in series the effective resistance becomes 9 ohm. Calculate the value of each resistance.
Answer:
Let the resistance be R, and R2 when two resistances are connected in series
R_S = R₁ + R₂
= 9
R₁ + R₂ = 9 ……….(1)
When two resistance are connected in parallel

Using (1) equation (2) becomes
\(\frac{9}{R_{1}R_2}\)
R₁ R₂ = 18 ……….(3)
(R₁ – R₂)² = (R₁ + R₂)² – 4R₁R₂
= (9)² – 4 × 18
= 81 – 72 = 9
∴ (R₁ – R₂) = √9 = 3 ………(4)
From (1)
R₁ + R₂ = 9
2R₁ = 12
∴ R₁ = \(\frac{12}{2}\) = 6 ohm
From (1)
R₂ = 9 – R₁
= 9 – 6 = 3Ω
The values of resistances are
R₁ = 6 ohm
R₂ = 3 ohm

Question 2.
How many electrons are passing per second in a circuit in which there is a current of 5 A?
Solution:
Current I = 5A
Time (t) = 1 second
Charge of electron e = 1.6 × 10^-19 C
\(\mathbf{I}=\frac{q}{t}=\frac{n e}{t}\)
Number of electron, n = \(\frac{\mathrm{I} t}{e}\) = \(\frac{5 \times 1}{1.6 \times 10^{-19}}\)
n = 3.125 × 10¹⁹.

Question 3.
A piece of wire of resistance 10 ohm is drawn out so that its length is increased to three times its original length. Calculate the new resistance.
Answer:
Resistance R = 10Ω
Let l be the length of the wire R ∝ 1
When the length is increased to three times,
l’ = 3l
∴ New Resistance
R’ ∝ l’ ∝ 3l
∴ \(\frac{R}{R’}\) = \(\frac{l}{3l}\) = \(\frac{1}{3}\)
∴ R’ = 3R
New resistance = 3 times the original resistance.

Samacheer Kalvi 10th Science Electricity Additional Important Questions and Answers

I. Choose the best answer.

Question 1.
Electric current is defined as the rate of flow of:
(a) energy
(b) power
(c) mass
(d) charge
Answer:
(d) charge

Question 2.
The S.I. unit of electric current is _____.
(a) Volt
(b) Power
(c) Ampere
(d) newton.
Answer:
(c) Ampere

Question 3.
The unit of electric current is:
(a) ampere
(b) volt
(c) watt
(d) kilo-watt
Answer:
(a) ampere

Question 4.
The work done in moving a charge of 2 C across two points in a circuit is 2 J. What is the potential difference between the points?
(a) 1 V
(b) 10 V
(c) 100 V
(d) 0.
Answer:
(a) 1 V

Question 5.
The amount of work done to move a unit charge from one point to the other is:
(a) resistance
(b) current
(c) Potential
(d) none of the above
Answer:
(c) Potential

Question 6.
Ohm’s law gives the relative between potential difference and:
(a) emf
(b) temperature
(c) resistance
(d) current
Answer:
(d) current

Question 7.
The unit of resistance is _____.
(a) volt
(b) volt ampere^-1
(c) ampere
(d) Joule.
Answer:
(b) volt ampere^-1

Question 8.
The symbol of battery is:

Answer:
(b)

Question 9.
Electrical resistivity for a given material is ______.
(a) zero
(b) constant
(c) both (a) and (b)
(d) only (b).
Answer:
(b) constant

Question 10.
The potential difference required to pass a current 0.2 A in a wire of resistance 20 ohm is:
(a) 100 V
(b) 4 V
(c) 0.01 V
(d) 40 V
Answer:
(b) 4 V

Question 11.
The unit of electrical conductivity ______.
(a) ohm^-1 metre
(b) ohm^-1 metre^-1
(c) Volt Ampere^-1
(d) ohm.
Answer:
(b) ohm^-1 metre^-1

Question 12.
Kilowatt-hour is the unit of:
(a) potential difference
(b) electric power
(c) electric energy
(d) charge
Answer:
(c) electric energy

Question 13.
The resistivity of a material is 4 × 10^-8 Ωm and its conductivity ______.
(a) 25 × 10^-8 mho m^-1
(b) 0.25 × 10^-8 mho m^-1
(c) 25 × 10⁸ mho m^-1
(d) 0.25 × 10⁸ mho m^-1.
Answer:
(d) 0.25 × 10⁸ mho m^-1.

Question 14.
The commonly used safely fuse wire is made of:
(a) nickel
(b) lead
(c) an alloy of tin and lead
(d) copper
Answer:
(c) an alloy of tin and lead

Question 15.
The value of one horse power is:
(a) 746 kW
(b) 746 W
(c) 3.6 × 10⁵ W
(d) 3.6 × 10⁶ kW
Answer:
(b) 746 W

Question 16.
When ‘n’ number of resistors are connected in series, the effecive resistance for series is ______.
(a) nR
(b) \(\frac{n}{\mathrm{R}}\)
(c) \(\frac{\mathbf{R}}{n}\)
(d) none of these.
Answer:
(a) nR

Question 17.
Name the physical quantity which is measured in kW:
(a) electric energy
(b) electric power
(c) electric current
(d) electric potential
Answer:
(b) electric power

Question 18.
What is the amount of current, when 20 C of charges flows in 4 s through a conductor? [l = \(\frac{q}{v}\)]
(a) 5 A
(b) 80 A
(c) 4 A
(d) 2 A
Answer:
(a) 5 A

Question 19.
Nichrome is ______.
(a) a conductor
(b) an insulator
(c) an alloy
(d) none of these.
Answer:
(c) an alloy

Question 20.
The main source of biomass energy is:
(a) coal
(b) heat energy
(c) thermal energy
(d) cow-dung
Answer:
(d) cow-dung

Question 21.
The value of one ampere is:
(a) \(\frac{1second}{1coulomb}\)
(b) 1 coulomb × sec
(c) \(\frac{1coulomb}{1second}\)
(d) 1 coulomb
Answer:
(c) \(\frac{1coulomb}{1second}\)

Question 22.
The heat produced in an electric heater of resistance 2 Ω is connected to an electric source, when a current of 6 A flows for 5 minutes _____.
(a) 216 × 10² J
(b) 2160 J
(c) 900 J
(d) 150 J.
Answer:
(a) 216 × 10² J
Hint: Formula H = I²Rt Joule.

Question 23.
The value of \(\frac{1joule}{1coulomb}\)
(a) 1 kWh
(b) 1 Wh
(c) ampere
(d) volt
Answer:
(d) volt

Question 24.
The mathematical from of Ohm’s law is given by:
(a) V = IR
(b) I = VR
(c) R = \(\frac{I}{V}\)
(d) I = \(\frac{R}{V}\)
Answer:
(a) V = IR

Question 25.
One kilowatt hour is _____.
(a) 3.6 × 10⁶ J
(b) 36 × 10⁶ J
(c) 3.6 × 10⁵ J
(d) 36 × 10⁵ J.
Answer:
(a) 3.6 × 10⁶ J

Question 26.
If the length and radius of a conductor is doubled then its specific resistance will:
(a) be doubled
(b) be halved
(c) be tripled
(d) remain the same
Answer:
(d) remain the same

Question 27.
The value of resistivity of nichrome is:
(a) 1.5 × 10⁶ Ωm
(b) 1.5 × 10^-6 Ωm
(c) 5.1 × 10⁶ Ωm
(d) 5.1 × 10^-6 Ωm
Answer:
(b) 1.5 × 10^-6 Ωm

Question 28.
Due to short circuit, effective resistance in the circuit becomes _____.
(a) large
(b) very small
(c) very large
(d) zero.
Answer:
(b) very small

Question 29.
if a conductor has a length of 1 m and area of 1 m² then its resistivity is equal to its:
(a) resistance
(b) conductance
(c) length
(d) conductivity
Answer:
(a) resistance

Question 30.
When resistors are connected in parallel, potential difference across each resistor will be:
(a) different
(b) same
(c) vary
(d) none of the above
Answer:
(b) same

Question 31.
LED TV screen was developed by James P. Mitchell in _____.
(a) 1797
(b) 1977
(c) 2009
(d) 1987.
Answer:
(b) 1977

Question 32.
Heat developed across a conductor H =
(a) IRt
(b) VR
(c) I²Rt
(d) I²R
Answer:
(c) I²Rt

Question 33.
Expression for electric energy is:
(a) W = \(\frac{V}{I}\)
(b) W = VIt
(c) W = Vt
(d) W = \(\frac{V}{It}\)
Answer:
(b) W = VIt

Question 34.
In our home, fuse box consists of:
(a) fuse wire
(b) MCB
(c) fuse wire or MCB
(d) switches
Answer:
(c) fuse wire or MCB

Question 35.
Which of the following is a semi conductor device?
(a) LED bulb
(b) fuse
(c) MCB
(d) switch
Answer:
(a) LED bulb

II. Fill in the blanks.

1. The flow of charge: Electric current. A continuous closed path of an electric current is ………. The unit of charge: Coulomb then-current ……….
2. Electric current I: Charge (Q)/ ………. while electric potential V is ……….
3. A resistor of resistance R:  Then variable resistance and ……….. rheostat ……….
4. In series connection of resistors: ………. Then for parallel connection of resistors: ………..
5. The transformation of energy in Electric oven: ………… Electric cell ………..
6. The expression obtained from Ohm’s law ………… joule’s law
7. The unit of electric power …………. then electric energy ………..
8. The equivalent of 1 volt ………. then for 1 ohm ………..
9. The tap-key is used to ……… and ……….. an electric circuit.
10. The opposition to flow of current is called ………. and its unit is ………..
11. The heat developed in a conductor is directly proportional to the square of ………… and ………. of flow.
12. The S.I unit of electric current is ……….
13. The S.l unit of resistance is ……….
14. ……….. is the S.l unit of potential difference.
15. From Ohm’s law \(\frac{V}{I}\) =
16. If a current 2A flows through conductor having a potential difference of 6 V then its resistance is ……….
17. If R is the resistance of a conductor then its conductance is G = ……….
18. Conductivity is ……… for ……….. than insulators.
19. When resistors are connected in series the equivalent resistance is …………. than the highest resistance of individual resistors.
20. In series connection ……….. is less as effective resistance is more.
21. Tungsten is used as heating element because its resistance is ……….
22. Tungsten is used as filament in the electric bulb because its melting points is …………
23. If a current of 6A flows through a 5Ω resistance for 10 minutes than heat developed in the resistance is ……….
24. When a current of IA flows through a conductor having potential difference of IV, the electric power is ………..
25. 746 watt is equivalent to ………..
26. In displays are used ………….
Answer:
1. Electric circuit, Ampere
2. Time (t), Work done (W)/charge (Q)
3.
4. Current is same, Potential difference is same
5. electrical into heat energy, chemical into electrical energy
6. V = IR, H = I²Rt
7. Kilowatt, want hour
8. \(\frac{1joule}{1coulomb}\), \(\frac{1volt}{1ampere}\)
9. open, close
10. resistance, ohm
11. current, time
12. ampere
13. Ohm 15. R
14. Volt
15. R
16. 3 ohm
17. \(\frac{I}{R}\)
18. more, conductors
19. greater
20. Current
21. high
22. high
23. 108 kJ
24. 1 W
25. 1 horse power
26. LED bulbs

III. State whether the following statements are true or false: If false correct the statement.

1. Current is the rate of flow of charges
2. The symbol of diode is

3. Potential = \(\frac{charge}{time}\)
4. Mathematical form of ohm’s law is V = IR
5. Nichrome is used in electric bulb.
6. The unit of conductance is mho.
7. The equivalent resistance in a parallel combination is less than the lowest of the individual resistance.
8. In parallel connection the effective resistance is R_P = \(\frac{R_{1}+R_{2}}{R_{1}R_{2}}\)
9. Heat produced in a conductor is H = l²Rt
10. 1 kWh = 3.6 J.
11. An MCB is a switching device.
12. LED means Light Emitting Diode.
Answer:
1. True
2. True
3. False – Potential = \(\frac{Workdone(W)}{Charge(Q)}\)
4. True
5. False – Nichrome is used in heating device.
6. True
7. True
8. False – In parallel connection, the effective resistance is R_P = \(\frac{R_{1}R_{2}}{R_{1}+R_{2}}\)
9. True
10. False – 1 kWh = 3.6 × 10⁶ J
11. True
12. True

IV. Match the items in column-1 to the items in column-ll.

Question 1.
Match the Column I with Column II.

Answer:
(i) – (d)
(ii) – (c)
(iii) – (a)
(iv) – (b)

Question 2.
Match the components with symbols

Answer:
(i) – (d)
(ii) – (c)
(iii) – (b)
(iv) – (a)

Question 3.
Match the Column I with Column II.

Answer:
(i) – (c)
(ii) – (d)
(iii) – (b)
(iv) – (a)

Question 4.
Match the Column I with Column II.

Answer:
(i) – (d)
(ii) – (c)
(iii) – (b)
(iv) – (a)

Question 5.
Match the column I with column II.

Answer:
(i) – (e)
(ii) – (d)
(iii) – (a)
(iv) – (b)

Question 6.
Match the column I with column II:

Answer:
(i) – (d)
(ii) – (e)
(iii) – (a)
(iv) – (b)

Question 7.
Match the column I with column II:

Answer:
(i) – (e)
(ii) – (a)
(iii) – (d)
(iv) – (c)

V. Assertion and reason type questions.

Question 1.
Assertion: In a series system, equivalent resistance is the sum of the individual resistance.
Reason: The current that passes through each resistor is the same.
(a) Assertion is true but Reason is false.
(b) Assertion is true and Reason doesn’t explains Assertion,
(c) Both Assertion and Reason are false.
(d) Assertion is true and Reason explains Assertion
Answer:
(d) Assertion is true and Reason explains Assertion

Question 2.
Assertion: In a parallel system, the total current is equal to the sum of the current through each resistor.
Reason: The potential difference across each resistor is the same.
(a) Assertion is true and Reason explains Assertion.
(b) Assertion is true and Reason doesn’t explains Assertion.
(c) Both Assertion and Reason are false
(d) Assertion is true but Reason is false.
Answer:
(a) Assertion is true and Reason explains Assertion.

Question 3.
Assertion: The unit of power watt is not frequently used in practice. Reason: it cannot be converted into Joule.
(a) Both Assertion and Reason are false.
(b) Assertion is true but Reason is false.
(c) Both Assertion and Reason are true and Reason explains Assertion.
(d) Both Assertion and Reason are true and Reason doesn’t explains Assertion.
Answer:
(b) Assertion is true but Reason is false.

Question 4.
Assertion: A wire carrying a current has electric field around d.
Reason: A wire carrying current is stays electrically neutral.
(a) If both the assertion and the reason a re true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.
Answer:
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.

Question 5.
Assertion: In order to pass current through electric circuit, it must be closed.
Reason: In our home, the switch is ON, then the current flows through the bulb. So, the bulb glows.
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.
Answer:
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.

Question 6.
Assertion: Resistance of a material opposes the flow of charges.
Reason: It is different for different materials.
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.
Answer:
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.

Question 7.
Assertion: Electrical conductivity is the reciprocal of electrical resistivity. Reason: The unit of conductivity is Ohm.
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.
Answer:
(c) If the assertion is true, but the reason is false.

Question 8.
Assertion: One end of the earthing wire is connected to a body of the electrical appliance and its other end is connected to a metal tube that is burried into the Earth.
Reason: The earth wire provides low resistance path to the electric current.
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.
Answer:
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.

Question 9.
Assertion: The passage of electric current through a wire results in the production of heat.
Reason: The heating effect is used in electric heater electric iron etc.
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.
Answer:
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.

Question 10.
Assertion: One kilowatt hour is known as one unit of electrical energy.
Reason: 1 kWh = 3.6 × 10⁶J
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.
Answer:
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.

VI. Very short answer type Questions

Question 1.
If a charge of QC flows through a conductor in time t second then what is the value of current?
Answer:
Charge = \(\frac{Charge}{time}\)
I = \(\frac{Q}{t}\)

Question 2.
What is the electric circuit?
Answer:
An electric circuit is a closed conducting loop.
(or)
path, which has a network of electrical components through which electrons are able to flow. This path is made using electrical wires so as to connect an electric appliance to a source of electric charges (battery).

Question 3.
If the length of a wire is doubled and its cross-section is also doubled than what happens its resistance?
Answer:
Resistance of a wire
R = \(\frac{pl}{A}\) ………. (1)
l’ = 2l
A’ = 2A
∴ New Resistance
R’ = l × \(\frac{2l}{2A}\)
R’ = \(\frac{pl}{A}\) …….. (2)
Form (1) and (2) it is found that resistance remains unchanged.

Question 4.
What is the unit of resistance and resistivity of a conductor?
Answer:
(i) The unit of resistance is ohm.
(ii) The unit of resistivity is ohm meter.

Question 5.
Define the unit of resistance? (or) Define one ohm.
Answer:
The resistance of a conductor is said to be one ohm if a current of one ampere flows through it when a potential difference of one volt is maintained across its ends.
\(\text { Ohm }=\frac{1 \text { volt }}{1 \text { ampere }}\).

Question 6.
What is the unit of conductivity?
Answer:
The unit of conductivity is mho meter.

Question 7.
What is the value of one kilo watt hour?
Answer:
One kilowatt hour = 1000 W hr
1 kWh = 3.6 × 10⁶J

Question 8.
What is the heating effect of electric current?
Answer:
The passage of electric current through a wire resulting in the production of heat. This phenomenon is called the heating effect of current. This heating effect of current is used in devices like electric heater, electric iron, etc.

VII. Short Answer Questions.

Question 1.
What is an electric circuit?
Answer:
An electric circuit is a closed conducting loop (or) path, which has a network of electrical components through which electrons are able to flow.

Question 2.
Draw a circuit diagram to represent a simple electric circuit.
Answer:

Question 3.
What is the direction of conventional current?
Answer:
By convention, the direction of current is taken as the direction of flow of positive charge (or) opposite to the direction of flow of electrons.

Question 4.
Define electric potential.
Answer:
The electric potential at a point is defined as the amount of work done in moving a unit positive charge from infinity to that point against the electric force.

Question 5.
What is meant by overloading?
Answer:
(i) Overloading happens when a large number of appliances are connected in series to the same source of electric power. This leads to a flow of excess current in the electric circuit.

(ii) When the amount of current passing through a wire exceeds the maximum permissible limit, the wires get heated to such an extent that a fire may be caused. This is known as overloading.

Question 6.
What is meany by short circuit?
Answer:

1. When a live wire comes in contact with a neutral wire, it causes a ‘short circuit’.
2. This happens when the insulation of the wires get damaged due to temperature changes or some external force.
3. Due to a short circuit, the effective resistance in the circuit becomes very small, which leads to the flow of a large current through the wires.
4. This results in heating of wires to such an extent that a fire may be caused in the building.

Question 7.
Draw an electric circuit to understand Ohm’s law.
Answer:

Question 8.
Define resistance of a conductor.
Answer:
The resistance of a conductor can be defined as the ratio between the potential difference across the ends of the conductor and the current flowing through it.

Question 9.
Define Resistance. Give its unit and conductance.
Answer:
The resistance of a conductor can be defined as the ratio between the potential difference across the ends of the conductor and the current flowing through it.
Conductance: It is defined as the reciprocal of its resistance (R). Hence, the conductance ‘G’ of a conductor is given by
\(\mathrm{G}=\frac{1}{\mathrm{R}}\)
Its unit is ohm^-1. It is also represented as ‘mho’.

Question 10.
Define electrical resistivity of a material.
Answer:
The electrical resistivity of a material is defined as the resistance of a conductor of unit length and unit area of cross section. Its unit is ohm metre.

Question 11.
What is meant by electrical conductivity?
Answer:
The reciprocal of electrical resistivity of a material is called its electrical conductivity.
σ = \(\frac{1}{p}\)

Question 12.
Mention the differences between the combination of resistances in series and parallel.
Answer:

Question 13.
Write short notes about filament in electric bulbs.
Answer:
In electric bulbs, a small wire is used, known as filament. The filament is made up of a material whose melting point is very high. When current passes through this wire, heat is produced in the filament. When the filament is heated, it glows and gives out light. Tungsten is the commonly used material to make the filament in bulbs.

Question 14.
What is meant by electric power?
Answer:
The electric power is the product of the electric current and the potential difference due to which the current passes in a circuit.

Question 15.
What is meant by overloading of an electric circuit?
Answer:
When the amount of current passing through a wire exceeds the maximum permissible limit, the wires get heated to such an extent that a fire may be caused. This is known as overloading.

Question 16.
What is meant by LED bulb?
Answer:
An LED bulb is a semiconductor device that emits visible light when an electric current passes through it. The colour of the emitted light will depend on the type of materials used.

Question 17.
W hat is meant by seven segment display? state its uses.
Answer:
(i) A ‘Seven Segment Display’ is the display device used to give an output in the form of numbers or text.
(ii) It is used in digital meters, digital clocks, microwave ovens, etc.

Question 18.
What do you know about LED television.
Answer:
LED Television is one of the most important applications of Light Emitting Diodes. An LED TV is actually an LCD TV (Liquid Crystal Display) with LED display. An LED display uses LEDs for backlight and an array of LEDs act as pixels. LEDs emitting white light are used in monochrome (black and white) TV; Red, Green and Blue (RGB) LEDs are used in colour television.

Question 19.
What is fuse wire?
Answer:
The function of fuse wire or an MCB is to protect the household electrical appliances from excess current due to overloading or a short circuit.

Question 20.
Draw a group between potential difference and current.
Answer:

Question 21.
Write short note about short circuit?
Answer:
When a live wire comes in contact with a neutral wire, it causes a ‘short ‘ circuit’. This happens when the insulation of the wires get damaged due to temperature changes or some external force. Due to a short circuit, the effective resistance in the circuit becomes very small, which leads to the flow of a large current through the wires. This results in heating of wires to such an extent that a fire may be caused in the building.

VIII. Long answer questions.

Question 1.
Tabulate various components used in electrical circuit and their uses?
Answer:

Question 2.
Explain series connection of parallel resistors.
Answer:

If we consider the connection of a set of parallel resistors that are connected in series, you get a series – parallel circuit. Let R₁ and R₂ be connected in parallel to give an effective resistance of R_p1. Similarly, let R₃, and R₄ be connected in parallel to give an effective resistance of R_p2. Then, both of these parallel segments are connected in series. Using equation we get

We get = R₁ + R₂ + R₃ ……….(1)
Finally, using equation (1), the net effective resistance is given by
R_total = R_P1 + R_P2

Question 3.
Explain parallel connection of series resistors.
Answer:
If you consider a connection of a set of series resistors connected in a parallel circuit, you get a parallel-series circuit. Let R₁ and R₂ be connected in series to give an effective resistance of R_S1. Similarly, let R₃ and R₄ be connected in series to give an effective resistance of R_S2. Then, both of these serial segments are connected in parallel.

Using equation
R_S = R₁ + R₂ + R₃
We get R_S1 = R₁ + R₂, R_S2 = R₃ + R₄
Finally, using equation
\(\frac{1}{R_P}\) = \(\frac{1}{R_1}\) + \(\frac{1}{R_2}\) + \(\frac{1}{R_3}\)
the net effective resistance is given by
\(\frac{1}{R_{total}}\) = \(\frac{1}{R_{S1}}\) + \(\frac{1}{R_{S2}}\)

Question 4.
Explain applications of heating effect.
Answer:
Electric Heating Device: The heating effect of electric current is used in many home appliances such as electric iron, electric toaster, electric oven, electric heater, geyser, etc. In these appliances Nichrome, which is an alloy of Nickel and Chromium is used as the heating element. Because:
(i) it has high resistivity,
(ii) it has a highmelting point,
(Hi) it is not easily oxidized.

Fuse Wire : The fuse wire is connected in series, in an electric circuit. When a large current passes through the circuit, the fuse wire melts due to Joule’s heating effect and hence the circuit gets disconnected. Therefore, the circuit and the electric appliances are saved from any damage. The fuse wire is made up of a material whose melting point is relatively low.

Filament in bulbs : In electric bulbs, a small wire is used, known as filament. The filament is made up of a material whose melting point is very high. When current passes through this wire, heat is produced in the filament. When the filament is heated, it glows and gives out light. Tungsten is the commonly used material to make the filament in bulbs.

Question 5.
Write short notes about
(i) LED bulb
(ii) Seven segment display
Answer:
(i) An LED bulb is a semiconductor device that emits visible light when an electric current passes through it. The colour of the emitted light will depend on the type of materials used. With the help of the chemical compounds like Gallium Arsenide and Gallium Phosphide, the manufacturer can produce LED bulbs that radiates red, green, yellow and orange colours. Displays in digital watches and calculators, traffic signals, street lights, decorative lights, etc., are some examples for the use of LEDs.

(ii) A ‘Seven Segment Display’ is the display device used to give an output in the form of numbers or text. It is used in digital meters, digital clocks, micro wave ovens, etc. It consists of 7 segments of LEDs in the form of the digit 8. These seven LEDs are named as a, b, c, d, e, f and g. An extra 8th LED is used to display a dot.

IX. Numerical problems.

Question 1.
An electric iron draws a current of 0.5 A when the voltage is 220 volts. Calculate the amount of electric charge flowing through it in one hour.
Answer:
I = \(\frac{Q}{t}\)
Charge Q = ?
Charge I = 0.5 A
Time = 1 hour
= 60 × 60 s
Q = It
= 0.5 × 3600
= 1800 C
The amount of electric charge flowing = 1800 C

Question 2.
A current of 5A flows through a heater for 10 minutes. Calculate the amount of electric charge flowing through the electric circuit.
Answer:
Q = I × t
Current I = 5A
Time t = 10 × 60 = 600 s
= 5 × 600 = 3000 C

Question 3.
A torch bulb draws a current 0.6 A, when glowing from a source of 6 V. Calculate the resistance of the bulb when glowing.
Answer:
V = IR
Current I = 0.6A
Potential V = 6V
R = ?
R = \(\frac{V}{I}\) = \(\frac{6}{0.6}\) = 10Ω
The resistance of the bulb = 10Ω

Question 4.
Find the potential difference required to pass a current of 0.2 A in a wire of resistant 20Ω.
Answer:
V = IR
Current I = 0.2A
Resistance R = 20Ω
Potential difference V = ?
V = 0.2 × 20 = 4V
The potential difference in a wire = 4V

Question 5.
Calculate the amount of work done in moving charge of 25 C across two points having potential difference of 20V.
Answer:
W = QV
Charge Q = 25 C
Potential difference V = 20 V
W = 25 × 20 = 500 J

Question 6.
Three resistances are connected in an electrical circuit as shown in the circuit diagram. Determine the potential difference across resistance R₂.
Answer:

For series connection, the effective resistance
R_S = R₁ + R₂ + R₃
= 1 + 2 + 3 = 6Ω
Total potential = 12V
Amount of current flowing through the circuit
I = \(\frac{V}{R_{S}}\) = \(\frac{12V}{6Ω}\) = 2A
Potential difference across resistance R₂
V = I × R₂
= 2 × 2 = 4V
The potential difference across the resistance R₂ = 4 V

Question 7.
In the given network, find the equivalent resistance between A and B.
Answer:

An equivalent of the given network is drawn in the relevant parts as follows: Resistance of the combination R₁ and R₂ is
R_S = 5 + 5 = 10Ω
Resistance of the combination R₁, R₂ and R₃ is

The resistance of series combination R_P1 and R₄ is R_S1 = 5 + 5 = 10Ω
Resistance of the combination R_S1 and R₅ is

Resistance of the series combination R_P2 and R₆ is
R_S2 = 5 + 5 = 10Ω
Resistance of the combination R_S2 and R₇ is

Resistance of the series combination R_P3 and R₈ is
R_P3 = 5 + 5 = 10Ω
Resistance of the combination R_S3 and R₉ is

Resistance of the series combination R_P4 and R₆ is
R_S4 = 5 + 5 = 10Ω
Resistance of the combination R_S4 and R₈ is

∴ Resistance between A and B is 5Ω

Question 8.
For a given circuit calculate
(i) the total effective resistance of the circuit.
(ii) the total current in the circuit
(iii) the current through each resistor.
Answer:

For parallel connection, the effective resistance

(i) Total effective resistance of the circuit
R_P = 0.588Ω

(ii) Total current in the circuit
I = 10.2 A

(iii) Current through R₁ = 6A
Current through R₂ = 3A
Current through R₃ = 1.2A

Question 9.
An electric iron a rating of 750 W, 220 V.
(i) Calculate current passing through it and
(ii) Its resistance when in use.
Answer:
P = VI
I = \(\frac{P}{V}\)
Ohm’s law V = IR

(i) The amount of current passing
I = 3.4A
(ii) Resistance
R = 64.7Ω

Question 10.
Following graph was plotted between V and I values. What would be the values of \(\frac{V}{I}\) ratios when the potential difference is 0.8 V and 1.2 V?
Answer:

V₁ = 0.8V, I₁ = 32A; V₂ = 1.2V; I₂ = 48A

Question 11.
Three resistors of 2Ω, 4Ω and 8Ω are connected in parallel with a battery of 3 V. Calculate
(i) Current through each resistor and
(ii) Total current in the circuit.
Answer:

Potential difference across each resistor is same.
(i) Current through each resistor:

(ii) Total current in the circuit: I = I₁ + I₂ + I₃
I = 1.5 + 0.75 + 0. 375
I = 2.625 A

Question 12.
Two bulbs of 40 W and 60 W are connected in series to an external potential difference. Which bulb will glow brighter? Why?
Answer:
Let the external potential difference be 230 V

For 40 W bulb resistance is R

For 60 W bulb resistance is R

According to Ohm’s law
I = \(\frac{V}{R}\)
Current flowing through 40 W bulb is
\(\frac{230}{1322.5}\) = 0.1739 A
Current flowing through 60 W bulb is
\(\frac{230}{881.6}\) = 0.2608 A
When bulbs are connected in series effective resistance is
R_S = R₁+ R₂ = 1322.5 + 881.6
R_S = 2204.1Ω
Net current
I = \(\frac{230}{2204.1}\) = 0.1043 A
Using power equation P = I²R
For 40 W bulb P = I²R
= (0.1043)² × 1322.5
= (0.01087) × 1322.5 = 14.386 W
For 60 W bulb P = I²R
= (0.1043)² × 881.6
= (0.01087) × 881.6 = 9.5904 W
In a series system, higher the resistance, higher the brightness so, 40 W bulb glows brighter.

Question 13.
A wire is bent into a circle. The effective resistance across the diameter is 8Ω. Find the resistant if the wire.
Answer:
R_P = 8Ω = resistance across diameter
\(\frac{1}{R}\) + \(\frac{1}{R}\) = \(\frac{1}{8}\)
\(\frac{2}{R}\) = \(\frac{1}{8}\)
R = 16Ω
x is the resistance of the wire.
x = 16 + 16 = 32Ω
x = 32Ω

X. HOT Questions.

Question 1.
A 60 W bulb is connected in parallel with a room heater. This combination is connected across the mains. If 60 W bulb is replaced by a 100 W bulb what happens to the heat produced by the heater? Given reason.
Answer:
Heat produced by the heater will be same. When the bulb and a heater are connected in parallel and this combination is connected across the mains, potential difference across each is the same equal to the voltage V of the mains irrespective of the resistance of the bulb.

If R is the resistance of the heater then heat produced by the heater will be \(\frac{V^2}{R}\) in both cases. Hence heat produces by heater will not be changed.

Question 2.
Two bulbs 60 W and 100 W are connected in series and this combination is connected to a d.c power supply. Will the potential difference across 60 W bulb be higher than that across 100 W bulb?
Answer:
60 W bulb has a higher resistance than the resistance across 100 W bulb since the power developed is P = \(\frac{V^2}{R}\).
Potential difference across a bulb will be proportional to resistance. Hence potential difference across 60 W bulb is higher than that across 100 W bulb.

Question 3.
Super conductors has lowest resistance. Is it true. Give reason.
Answer:
True. When the temperature of super conductor is reduced to zero or near by zero its resistance becomes zero.

Question 4.
A constant voltage is applied between two ends of a uniform conducting wire. If both the length and radius of the wire is doubled then what happens to the heat produced in the wire?
Answer:
We know that resistance of a conducting wire is R = \(\frac{pl}{A}\)
\(\frac{Pl}{πr^{2}}\)
If length l and radius r are doubled, then resistance will become half. But heat produced H = \(\frac{V^2}{R}\).
Hence, heat produced per second will become thrice.

Question 5.
Calculate the effective resistance between A and B.
Answer:

The electrical circuit can be redrawn as

The resistance R₁ and R₂ are in series
R_S = R₁ + R₂ = 2 + 2 = 4Ω
The resistance R_S and R₃ are in parallel

∴ Effective resistance R_eff= 1.33Ω

Question 6.
Two wires of same material and length have resistances 5Ω and 10Ω respectively. Calculate the ratio of radii of the two wires.
Answer:
Resistance

∴ r₁ : r₂ = √2 : 1

Question 7.
An iron box of 400 W power is used daily for 30 minutes. If the cost per unit is 75 paise, find the weekly expense on using the iron box.
Answer:
Power P = 400 W

Energy consumed = Power × Time
= 400 × \(\frac{1}{2}\) = 200 Wh
Energy consumed in one week= 200 × 7
= 1400 Wh = 1.4 kWh
= 1.4 unit
∴ Total cost per week = 1.4 × 0.75 = Rs 1.05
Weekly expense = Rs 1.05

Students can Download Samacheer Kalvi 10th English Model Question Paper 1 Pdf, Samacheer Kalvi 10th English Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamil Nadu Samacheer Kalvi 10th English Model Question Paper 1

General Instructions:

1. The question paper comprises of four parts.
2. You are to attempt all the sections in each part. An internal choice of questions is provided wherever applicable.
3. All questions of Part I, II, III and IV are to be attempted separately.
4. Question numbers I to 14 in Part I are Multiple Choice Questions of one mark each. These are to be answered by writing the correct answer along with the corresponding – option code.
5. Part II has got four sections. The questions are of two marks each. Question numbers 15 to 18 in Section I and Question numbers 19 to 22 in Section II are to be answered in about one or two sentences each. Question numbers 23 to 28 in Section III and IV are to be answered as directed.
6. Question numbers 29 to 45 in Part III are of five marks each and have been divided in five sections. These are to be answered as directed.
7.  Question numbers 46 and 47 in Part IV are of eight marks each. Question number 47 has four questions of two marks each. These are to be answered as directed.

Time: 2.30 Hours
Maximum Marks: 100

Part – I

Answer all the questions. [14 x 1= 14]
Choose the most suitable answer and write the code with the corresponding answer.
Choose the appropriate synonyms for the italicised words.

Question 1.
The whole family walked about on the big plateau.
(a) highland
(b) pinnacle
(c) lake
(d) valley
Answer:
(a) highland

Question 2.
Before I could intervene, the cops were in the attic.
(a) interfere
(b) interrogate
(c) instigate
(d) investigate
Answer:
(a) interfere

Question 3.
Nagen had a rustic look.
(a) urban
(b) rural
(c) modem
(d) crude
Answer:
(d) crude

Choose the appropriate antonym for the italicised words.

Question 4.
I gave my crew members the best dishes with the limited resources.
(a) limitations
(b) partial
(c) incomplete
(d) boundless
Answer:
(d) boundless

Question 5.
They continue to grapple with the challenges of inclusion.
(a) seclusion
(b) enclosure
(c) addition
(d) exclusion
Answer:
(d) exclusion

Question 6.
The man was startled.
(a) annoyed
(b) alarmed
(c) reassured
(d) amused
Answer:
(c) reassured

Question 7.
Choose the correct plural form of ‘millennium’.
(a) millennia
(b) millenniums
(c) millenniumes
(d) millenniaas
Answer:
(a) millennia

Question 8.
Form a derivative by adding the right suffix to the word – imagine.
(a) or
(b) ary
(c) al
(d) tion
Answer:
(d) tion

Question 9.
Choose the correct expansion of the abbreviation SAARC.
(a) South African Association for Regional Cooperation
(b) South Asian Association for Railways Cooperation
(c) South Asian Association for Regional Cooperation
(d) South Asian Association for Regional Corporation
Answer:
(c) South Asian Association for Regional Cooperation

Question 10.
Complete the following sentence with the most appropriate phrasal verb given below:
The match was ……………. due to rain.
(a) called upon
(b) called on
(c) called off
(d) called at
Answer:
(c) called off

Question 11.
Choose the suitable option to pair it with the word ‘flower’ to form a compound word.
(a) sun
(b) rain
(c) sky
(d) son
Answer:
(a) sun

Question 12.
Fill in the blank with the most appropriate preposition given below:
The cat was hiding …………………….. the table.
(a) by
(b) under
(c) at
(d) for
Answer:
(b) under

Question 13.
Complete the following sentence using the most appropriate tense form of the verb given below:
I speak, and the words appear on my screen and then ……………………….. I them out.
(a) can be printed
(b) can printing
(c) were printed
(d) can print
Answer:
(d) can print

Question 14.
Choose the most appropriate linker from the given four alternatives.
The baby isn’t sleeping, ………………………. it’s late.
(a) in spite
(b) even though
(c) although
(d) so
Answer:
(b) even though

Part – II [10 x 2 = 20]

Section -I

Answer any THREE of the following questions in a sentence or two. [3 x 2 = 6]

Question 15.
What happened to the young seagull when it landed on the green sea?
Answer:
When the young seagull landed on the green sea, he completely forgot that he had not always been able to fly and shrieked shrilly, turning his beak sideways and crowed amusedly. He screamed with fright when he dropped his legs to stand on the green sea and sank into it.

Question 16.
What was the mean act of Holmes with Dr. Watson?
Answer
When Dr. Watson offered to examine symptoms and treat him Holmes said he would have a doctor in whom he had confidence. This was really very rude of Holmes and showed his madness.

Question 17.
What is the meaning of Tarini? Why is it worshipped?
Answer
The word ‘Tarini ’ means ‘boat ’ and in Sanskrit it means ‘ Saviour ’. Tara – Tarini is worshipped for safety and success at sea.

Question 18.
What did Sasanka tell Aditya, looking at the fifteen ten-rupee notes in his hand?
Answer
Sasanka said to Aditya, ‘Aditya, this smacks too much of charity. Doesn’t it? I had recognised you at Nagen uncle’s tea shop by that mole on your right cheek. I could see you had not recognised me. So I recited the same poem that I had recited on the prize-giving day, on purpose, so that you may remember. Then, when you came to visit me, I couldn’t help venting my anger on you.’

Section – II

Read the following sets of poetic lines and answer any THREE of the following. [3 x 2 = 6]

Question 19.
“In the dim past, nor holding back in fear From what the future veils; but with a whole And happy heart, that pays its toll
To Youth and Age, and travels on with cheer.”
(a) How can one travel on with cheer?
(b) What is meant by ‘veil’?
Answer
(a) One can travel cheerfully with a happy heart.
(b) A veil is a cover that is used to partially hide something.

Question 20.
“And so it were wisest to keep our feet From wandering into Complaining Street;”
(a) What is the wisest thing that the poet suggests?
(b) What does the phrase ‘to keep our feet from wandering’ refer to?
Answer
(a) The wisest thing is to avoid wandering into the complaining street.
(b) The phrase, ‘to keep our feet from wandering’ refer to restricting your path from strolling.

Question 21.
“At last by starvation and famine made bold,
All dripping with wet, and all trembling with cold,”
(a) What made the cricket bold?
(b) Why did the cricket drip and tremble?
Answer
(а) Starvation and hunger made the cricket bold.
(b) The cricket dripped wet and trembled with cold because it was winter.

Question 22.
“Some water, coal, and oil is all we ask,
And a thousandth of an inch to give us play:
And now, if you will set us to our task,
We will serve you four and twenty hours a day!”
(a) What is the requirement of the machines?
(b) What does the second line indicate?
Answer
(a) The requirement of the machines is water, coal and oil.
(b) The second line indicates the close arrangement of the nuts, screws and bolts.

Section – III

Answer any THREE of the following. [3 x 2 = 6]

Question 23.
Rewrite the following sentence to the other voice.
Answer
I will never forget this experience.
This experience will not be forgotten by me

Question 24.
Rewrite using indirect speech.
Answer
They asked us, “Are you going anywhere at the weekend.?”
They asked us if we were going anywhere at the weekend.

Question 25.
Punctuate the following.
Answer

• M Hamel saw me and said very kindly go to your place quickly, little Franz we were beginning without you
• M. Hamel saw me and said very kindly, “Go to your place quickly, little Franz. We were beginning without you

Question 26.
Transform the following sentence into a simple sentence.
Answer
He is rich, yet he is unhappy.
Despite being rich he is unhappy.

Question 27.
Rearrange the words in the correct order to make meaningful sentences.
(a) Six puppies / to/ had / Maya’s / given birth / dog
(b) Many times / Sita told Ravi / two dogs / have / already / we
Answer
(a) Maya’s dog had given birth to six puppies.
(b) Many times Sita told Ravi we already have two dogs.

Section – IV

Answer the following. [1 x 2 = 2]

Question 28.
Help the stranger from Mariadass street to reach his/her destination, Madha Poonga with the help of the given road-map and write down the steps

• From Mariadoss street, proceed further and take the left at the crossroads on P.V.Koil Street.
• Go further down and cross Andhra Post office on the left and R.K.Oil Mill on the right.
• After half a furlong, you must take the right on P. V.Koil street where you will find Madha Poonga on the left.

Part – III [10 x 5 = 50]
Section – I

Answer any TWO of the following in utmost 10 lines. [2 x 5 = 10]

Question 29.
What do you know about James Thurber, the narrator?
Answer:
The narrator James Thurber, presents himself as acting judiciously, although his actions are uncommon to raise the uncertainties of the policemen. He is the first person in the household to hear the mysterious sound, as he is stepping out of the bathtub at 1:15 a.m. on November 17th. After waking his brother Herman, he is the one who resolves that the reason of the sound downstairs must be an apparition. When his hasty mother decides that the sounds must be caused by intruders, the narrator thinks that she is past reasoning. Even when the cops arrive, he is still wrapped in a towel from his bath.

Later, when the reporter comes around asking questions, the narrator puts on one of his mother’s blouses, explaining that it is the only thing that he can find at the moment. He chooses to be honest with the reporter and tell him that the problem was caused by ghosts, but the reporter does not take him earnestly. Later, when the policeman who has been shot by Grandfather wants to challenge him and take his gun back, the narrator mediates with composed receptivity and offers to take the gun over to the police station in the morning.
“A judicious reticence is hard to learn, but
it is a lifetime lesson.’’

Question 30.
What are the various innovations made in India to help the differently-abled lead a normal life?
Answer:
There are various innovations made in India to help the differently abled lead a normal life. Lechal Shoes by Krispian Lawrence is an innovation for the disabled to use GPS & Blutooth. This enabled shoes to help the disabled navigate streets, based on instructions from map software on a smartphone. The App also records the route and also counts steps.

Blee Watch by industrial designers Nupura Kirloskar and Janhavi Joshi of Mumbai invented the Smart watch for the hearing impaired. It converts sound waves into vibrations and colour codes to alert users to emergency sounds and ringing doorbells. It even helps them feel the rhythm of music. iGEST by Anil Prabhakar, IIT-M professor and cofounder of enability technologies innovated a wearable device which tracks gestures of speech-impaired people and speaks for them. I guess technology makes a differently abled person’s life easier.
“Exploration is the engine that drives Innovation.”

Question 31.
What do you know about the Navikaa Sagar Parikrama?
Answer:
Navika Sagar Parikrama was a project undertaken in consonance with the National policy to empower women to attain their full potential. The Project is considered essential towards promoting ocean sailing activities in the Navy while depicting Government of India’s thrust for Nari Shakti which means women power. The Chief of the Naval Staff, Admiral Sunil Lanba gave his welcome speech when this project was launched.

The voyage was aimed to show case ‘Make in India’ initiative by sailing on-board indigenously built INSV Tarini. The special feature of this sailboat is that it encouraged use of environment friendly non-conventional renewable energy resources such as the wind; collected and updated meteorological, ocean and wave data on regular basis for accurate weather forecast by India Meteorological Department (IMD) and also collected data for monitoring marine pollution on high seas.
“The goal is not to sail the boats, but rather to help the boat sail herself.’’

Question 32.
‘Man does change with time’-What were the various changes that came about in Aditya?
Answer:
Man does change with time. According to Sanyal, Aditya was a boy who could never compete him in scholastic or non-scholastic activities. He was a liar and an envious personality. But, years later Aditya no longer is the same personality. He is more matured and responsible. His childish nature makes him feel guilty, for stealing the medal that belonged to Sanyal.

Aditya now wanted to restore Sanyal, his lost happiness. Knowing about his financial constraints, he decides to give him the cost of the silver medal. He drives with a firm determination to his ancestral house. When he reaches, he rushes to the attic. Aditya gets on top of a packing Case and pushes his hand inside the ventilator, upsetting a sparrow’s nest. However, he heaves a sigh of relief when he gets what he had been looking for. He goes straight to the Jeweller to determine the current rate of the medal in the market. All these surely show a remarkable change in him.

Even when Sanyal behaves rudely, Aditya is courteous and friendly. His only intention is penitence. He is so mature that he even understands and justifies the grievances Sanyal had in his heart. When Sanyal prefers the medal, without second thoughts he restores it to Sanyal whole-heartedly.
“Change is universal.”

Section – II

Answer any TWO of the following in utmost 10 lines. [2 x 5 = 10]

Question 33.
Narrate the fable of ‘The Ant and the Cricket’ in your own words.
Answer:
The silly young cricket was fun-loving. He used to sing all through the pleasant sunny months of summer and spring. He was short-sighted. He didn’t bother to store food for the rainy season and cold winter. When the earth was covered with ice and snow, he found that he had nothing to eat and his cupboard was empty. There were no flowers nor leaves on the trees. He grew nervous. Starvation could be seen over his face. Wet with the rain and shivering with cold, the hungry cricket went to an ant to get shelter and food.

He made it clear that he would return the borrowed grain the next day. With humility, the miserly ant said that he was surely the servant and friend of the cricket. But as a matter of principle, the ants neither borrow nor lend. He asked why he never bothered to store something for the rainy day. The cricket admitted that he had been careless and foolish. He enjoyed the beauties of summer and sang merrily. The ant then told him bluntly to go and dance all winter and turned the poor cricket out.
‘Prudence is foresight and farsightedness. ’

Question 34.
The poem ‘No men are foreign’ has a greater relevance in today’s world. Elucidate.
Answer:
The poet, James Kirkup, quotes various instances to prove that no men are foreign. The very title of the poem is thought-provoking and forces the reader to think about the issue of people living in other countries as foreigners and strangers. As the poem advances, the poet recurrently emphasises that all human beings are indistinguishable in their nature and tactics. All live on the same earth; enjoy air, sun and water; love peace and are opposed to war.

They all have mutual experiences and toil in a similar manner to earn the living. The realistic reasoning put forth by the poet and the numerous reminders fully satisfy the reader that no men are foreign. He gets the message that alienation from fellow brethren is equally damaging to himself. He also understands that by treating other men as foreign, the world stands exposed to the risk of war which can lead to permanent destruction and pollution of mother earth. It is true that many people have been telling us to live harmoniously since long. We never follow their message.

We also know that our greed to get more wealth and power cannot give us peaceful life. But some deep-rooted evils in our society make us draw a distinction between people. We know that all customs and conventions have been made by people. We start to hate even our family members due to our ego to be more powerful. By doing so, we at last harm ourselves. In society, people dislike selfish people. So before going to hurt other’s feeling, first of all we should think whether doing such act with others are justified by other people or society.
‘Smile at strangers and you just might change a life. ’

Question 35.
Read the following stanza and answer the questions given below.
“Let me but live my life from year to year,
With forward face and unreluctant soul;
Not hurrying to, nor turning from the goal; – Not mourning for the things that disappear ”
(i) Pick out the alliterated words in the first line.
(ii) What is the figure of speech used in the second line?
(iii) Pick out the rhyming words from the above lines.
(iv) Give an example of the usage of couplet in the above stanza.
Answer:
(i) ‘Let, live, life’ are the alliterated words in the first line.
(ii) The figure of speech is alliteration, (e.g. forward face)
(iii) Year and disappear; soul and goal are the rhyming words.
(iv) With forward face and unreluctant soul;
Not hurrying to, nor turning from the goal;

Question 36.
Paraphrase the following stanza.
Some water, coal, and oil is all we ask,
And a thousandth of an inch to give us play:
And now, if you will set us to our task,
We will serve you four and twenty hours a day!
Answer:
Here it is clearly stated that the only requirement for the machine is water, coal and oil. The moving parts may have a clearance of a thousandth of an inch which may be the permissible variation from the required dimensions. These parts are closely arranged with bolts and nuts leaving only less than an inch for the movement of wheels. With such a setup, the machines are willing to work round the clock, non-stop without any rest.

Section – III

Answer any ONE of the following: [1 x 5 = 5]

Question 37.
Rearrange the following sentences in coherent order.
(i) Peter’s mother asked Peter to go across the dike and take cakes to his friend.
(ii) The little boy was glad to go on such an errand, and started off with a light heart.
(iii) Holland is a country where much of the land lies below sea level.
(iv) Even the little children know the dikes must be watched every moment.
(v) Peter’s father opened and closed the sluices for ships to pass out of Holland’s canals into the great sea.
Answer:
Rearranged number sequence: (iii), (iv), (v), (i), (ii)
(iii) Holland is a country where much of the land lies below sea level.
(iv) Even the little children know the dikes must be watched every moment.
(v) Peter’s father opened and closed the sluices for ships to pass out of Holland’s canals into the
great sea.
(i) Peter’s mother asked Peter to go across the dike and take cakes to his friend.
(ii) The little boy was glad to go on such an errand, and started off with a light heart.

Question 38.
Read the following passage and answer the questions that follow.
The next room, a broad gallery about a quarter of a mile long, was devoted to publicity, and it well may be imagined what the publicity for such a journal as the Earth Herald had to be. It brought in a daily average of three million dollars. They are gigantic signs reflected on the clouds, so large that they can be seen all over a whole country.

From that gallery a thousand projectors were unceasingly employed in sending to the clouds, on which they were reproduced in colour, these inordinate advertisements. At that moment the clock struck twelve. The director of the Earth Herald left the hall and sat down in a rolling armchair. In a few minutes he had reached his dining room half a mile away, at the far end of the office. The table was laid and he took his place at it.

Within reach of his hand was placed a series of taps and before him was the curved surface of a phonotelephote, on which appeared the dining room of his home in Paris. Mr and Mrs Bennett had arranged to have lunch at the same time – nothing could be more pleasant than to be face to face in spite of the distance, to see one another and talk by means of the phonotelephotic apparatus.
Questions
(i) Where was the broad gallery?
(ii) What happened in the broad gallery?
(iii) What was the income of the Earth Herald every day?
(iv) Why did the director sit on the roiling armchair?
(v) State the use of the phonoteleohote.
Answer:
(i) The broad gallery was in Earth Herald, the world’s largest newspaper.
(ii) The broad gallery was devoted to publicity. From that gallery a thousand projectors were unceasingly employed in sending to the clouds, on which they were reproduced in colour, inordinate advertisements.
(iii) The income of Earth Herald was an average of three million dollars every day.
(iv) He sat down in a rolling armchair to reach his dining room which was half a mile away, at the far end of the office.
(v) One can see each other and talk by means of the phonotelephotic apparatus.

Section – IV

Answer any FOUR of the following. [4 x 5 = 20]

Question 39.
Prepare an attractive advertisement using the hints given below.
Branded water purifier – Introductory offer only Rs. 8,500/-. Best virus remover

Question 40.
You are S. Sundaram. Write a letter to the Commissioner of Chennai Corporation, complaining about the poor sanitary conditions and mosquito menace in your locality.
Answer:
S. Sundaram
34, Periyar Road
Chennai-46
19 September, 20XX
The Commissioner
Chennai Municipal Corporation
Chennai
Sir,
Sub: Poor sanitary conditions and mosquito menace in Periyar Road I want to draw your kind attention towards the poor sanitary conditions prevailing in our locality – Periyar Road. It seems that the cleaners have forgotten the existence of this locality on the civic map of Chennai. Heaps of rubbish are lying here and there, with flies swarming around and pigs wallowing in the filth and mud caused by the overflow of dirty water from the drains on to the road. The drains are choked as they are neither cleaned nor flushed.

The dirty water collects on the road forming cesspools of filthy water. There are also many pits on the roads which are full of drain water. All these serve as breeding places for mosquitoes. The mosquito menace is so intense in our locality that we have to use anti mosquito sprays, mats and repellants have undisturbed sleep for a couple of hours. You are requested to pay
a surprise visit to the locality and judge the state yourself. Kindly take some immediate and effective steps to improve the sanitation and rid us of the menace of mosquitoes.

Hoping for a favourable action.
Yours faithfully
S. Sundaram

Address on the envelope
To
The Commissioner
Chennai Municipal Corporation
Chennai

Question 41.
You are Juliet / Gideon, Gymkhana Club of Coimbatore. Draft a notice to be sent to the members asking them to attend the extraordinary meeting of the Governing Body (Insert the necessary details).
Answer:

Gymkhana Club, Coimbatore 10 March 20XX NOTICE Members are requested to make it convenient to attend an extraordinary meeting of the Governing Body to discuss amendments in guest charges and monthly subscriptions. Date : 20th March 20XX Time : 7 p.m. Place : Gymkhana Club Complex, Coimbatore Governing Body members are requested to stay for dinner. Prabhat/Parvi Secretary

Question 42.
Look at the following picture and express your views on it in about five sentences.

Answer:
Circus
In the world of public entertainment, circus occupies a prominent place. We feel thrilled to watch the antics of the lion, bear and elephants who dance to their ring master’s tunes. Animals were born free, but man has tamed them and uses them for his own benefit. The tricks and feats of these animals provide a sheer contrast to the adventurous feats of performing artistes. The children express their joy with clapping while the grown-ups just marvel at the daredevilry of the ringmasters.

Question 43.
Make notes or write a summary of the following passage.
Answer:
The greatness of a country depends upon its people. India is fortunate to have vast human resources. Our countrymen are second to none in intelligence and in doing hard work. From the ancient period Indians excelled in art, architecture, knowledge of metals, medicines, literature etc., After our independence in 1947, the Government took steps to improve our country in all sphere. By the first Five-Year Plan was specially designed to improve our irrigational methods. By the five year plans, provisions are made for the development of the country.

The first Five-Year Plan was specially designed to improve our irrigational methods. By the green revolution we attained self sufficiency in the field of agricultural production. The present age is the atomic age. India too established an Atomic Energy Commission under the guidance of Dr. Bhabha. India made the first successful nuclear explosion on 18th Mary, 1974 which made India the sixth member of the world nuclear club.

No other country’s scientists helped; it was purely Indian efforts. We have sent our Indian cosmonaut to space also. On April 3,1984 Shri Rakesh Sharma, the best pilot of Indian Air Forse, travelled into space with two Soviet spacemen in Soyuz II spaceship.

Notes
Title: Greatness of India
1. (a) Greatness of the country – people
(b) our country men are second to none
(c) From the ancient people Indians excelled in arts and crafts
(d) After Independence Government took steps to improve in all spheres
(e) The first five year plan was designed
(f) Green revolution attained self sufficiency

2. (a) The present age is the atomic age
(b) India made the first nuclear explosion
(c) India sent cosmonauts to space

Summary

Title: Greatness of India
Rough Draft
India fortunate to have vast human resources. Our countrymen are second to none in intelligence and in doing hard work. Ancient Indians excelled in art, architecture, metallurgy, medicine, literature etc After Independence, by the five year plans, provisions are made for the development of the country green revolution we attained self sufficiency in the field of agricultural production. Present age is the atomic age. An Atomic Energy Commission under the guidance of Dr. Babha. Due to the successful clear explosion in 1974, India the sixth member of the world nuclear club. It was purely Indian effort we have sent Rakesh Sharma to space in Soyuz II.

Fair Draft:

India is fortunate to have vast human resources. Ancient Indians excelled in art, architecture, metallurgy, medicine, literature etc., After Independence by the green revolution we attained self sufficiency in agricultural production. Present age is the atomic age. Due to the successful nuclear explosion in 1974, India is the sixth member of the world nuclear club.
No. of words in the Fair Draft: 55

Question 44.
Identify and correct the errors in the following sentences.
(a) A group of twelve students are travelling together from Mumbai to Kanyakumari by the last week of September.
(b) One of his sons are a doctor by profession in the United States of America for nearly ten years.
(c) The decoration of the new house, including the furniture are most pleasing.
(d) Though senior in age, his father is junior than my father in service.
(e) He is going everyday for a morning walk with his friends and neighbours.
Answer:
(a) A group of twelve students are travelling together from Mumbai to Kanyakumari in the last week of September.
(b) One of his sons is a doctor by profession in the United States of America for nearly ten years.
(c) The decoration of the new house, including the furniture is most pleasing.
(d) Though senior in age, his father is junior to my father in service.
(e) He goes everyday for a morning walk with his friends and neighbours.

Section – V

Quote from memory. [1 x 5 = 5]

Question 45.
Remember, no …………… and water.
Answer:
Remember, no men are strange, no countries foreign
Beneath all uniforms, a single body breathes
Like ours: the land our brothers walk upon
Is earth like this, in which we all shall lie.
They, too, aware of sun and air and water,

Part – IV

Write a paragraph of about 150 words by developing the following hints. [2 x 8 = 16]

Question 46.
(a) Love of a son for his mother – opposition to the law – tyrant – elderly people inefficient – importance of aged people – decree. Foothills – proclamation – cruel decree – killing aged people wasn’t common – poor farmer distressed.
Answer:
“The Aged Mother” by Matsuo Basho is a Japanese folklore about the love of a son for his mother and the mother’s love in return for her son. They encountered this agony as an opposition to the law of placing aged people to death. The tyrant stated the law of killing the elderly people because he was a warrior himself who felt that only the young men and women who were robust were useful to the country. According to the warrior, elderly people were inefficient and couldn’t be obliging to individuals who were however healthy as him.

To such a despotic leader, the importance of aged people was insignificant. Hence, he pronounced it as a decree. When the poor farmer and his aged mother who lived in a poor hut of the foothills in the country of Shining heard the proclamation by the despotic leader who announced the cruel decree of killing elderly people in that place, their heart was distressed. During this period, killing aged people wasn’t common. Therefore, when the poor farmer came to know of the decree he bore sadness in his heart. He was extremely concerned and was in deep thoughts to make an escape.

[OR]

(b) Narrate the story of Zigzag by developing the following hints.
Dr. Ashok T Krishnan’s family – shelter Somu’s new pet – talks twenty-one languages – genuine African witch doctor’s gift – to Mrs Krishnan a nuisance – children Arvind, Maya – the unique gifts – ZigZag, a disappointment – steadfast sleep – chandelier and fan blades – maid Lakshmi – unfinished masterpiece -e-mail – seventh day – reply – Zig Zag’s snore take a turn – at the clinic.
Answer:
Dr. Ashok T Krishnan’s family shelters Somu’s new pet, Zig-Zag, a queer-looking African bird, who is known for talking and singing in twenty-one different languages. They consider Zigzag to be a harmless, unusual and lovable bird bred by a genuine African witch doctor, who gifted it to Somu when he toured the deepest jungles of Africa. To Somu, the bird is an absolute treasure and a real help. Mrs. Krishnan considers it a nuisance.

Their son Arvind and daughter Maya are keen on having the pet. They both discuss the unique gifts given by Uncle Somu viz insect-eating plant, tiny shark teeth penknife and the aboriginal boomerang. ZigZag turns out to be a disappointment for the Krishnan family. Zigzag does nothing but sleep and snore to annoy all around. All attempts to awaken the bird goes in vain. The bird at first before resorting to a steadfast sleep eats the nuts and fruits, keeps them safe in the chandelier and the fan blades.

The maid Lakshmi shrieks in an excited manner thinking she is blessed with papayas and bananas raining inside the room. Mrs. Krishnan is annoyed at the slice of overripe papaya whizzing off the fan and splattering all over her unfinished masterpiece – Sunset at Marina spreading streaks of gooey orange pulp and shiny black seeds all over it. Dr. Krishnan leaves an e-mail message for Somu, asking him for clear instructions on how to stop Zigzag from snoring. On the seventh day, they receive the reply that he never sleeps nor snores. Mrs. Krishnan wants it to be sent to Visu as her friends and experts will come home and choose her paintings for the exhibition. Krishnan takes ZigZag in the car and hopes to find Visu so that ZigZag’s snore doesn’t add to the din of the sobs and shrieks produced by the tiny patients waiting for him.

However, Ziggy-Zagga, King-of-the-Tonga, was not familiar to being kept waiting, makes his way to the clinic where he perches himself on the nurse’s reception table. Suddenly things take a turn when ZigZag starts speaking. It’s Zigzag’s voice, clear and commanding. Gone was Zigzag’s bored and grumpy expression. Instead, the bird looked happy and alert as it went about the job it had been trained for, first with the African witch doctor and then with Dr. Somu.

Question 47.
Read the following passage and answer the questions given below:
Answer:
Rambutan is a close cousin of the litchi fruit, but not as well known. It is a member of the Sapindaceae family and resembles the litchi, except for its long, flesh coloured spines. Rambutan (Napheluim lappaceum) is an ever green tropical tree which reaches a height of 50 to 80 feet and has a straight trunk, with a dense spreading crown. There are both male and female trees and only female trees bear fruit. It grows best in deep, clay loam or sandy loam rich in organic matter.

Rambutan is usually propagated by seeds. The seeds taken from the fruit, may be planted horizontally with the flattened side downward so that the seeding grows straight and has a strong root system. While harvesting the entire fruit cluster must be cut from the branch. The fruit must be kept dry and well ventilated to prevent them from getting spoilt. The peeled fruits are occasionally stewed as dessert.

Questions.
(a) Which fruit does the Rambutan look like?
(b) What is the botanical name for Rambutan?
(c) What kind of soil is ideal for Rambutan?
(d) Why should the seed be planted horizontally?
Answer:
(a) Rambutan looks like the litchi but for the long, flesh coloured spines.
(b) The botanical name for Rambutan is Napheluim lappaceum.
(c) Rambutan grows best in deep, clay loam or sandy loam rich in organic matter.
(d) The seed should be planted horizontally with the flattened side downward so that the seeding grows straight and has a strong root system.

[OR]

Read the following poem and answer the questions given below:
All are over: does truth sound bitter As one at first believes?
Mark, ‘tis the sparrow’s good night twitter About our cottage eaves?
And the leaf-buds on the vine are woolly,
I noticed that, today;
One day more bursts them open fully You know the red turns grey.
Tomorrow we meet the same then, dearest?
May I take your hand in mine?
Mere friends are we — well, friends the merest Keep much that I resign:
For each glance of the eye so bright and black,
Though I keep with heart’s endeavour, —
Your voice, when you wish the snowdrops back,
Though it stays in my soul forever!
Yet I will but say what mere friends say,
Or only a thought stronger.
I will hold your hand but as long as all may,
Or so very little longer.

Questions.
(a) What is meant by the words, ‘All are over’?
(b) What did the poet note?
(c) What is the deep-rooted desire of the poet?
(d) What are the two things praised in the poem?
Answer:
(a) ‘All are over’ means that the love affair between the lover and his mistress has come to an end.
(b) The poet noted the sparrow’s good night twitter in the cottage roof-space and the leaf- buds on the vine which had gone woolly.
(c) The deep-rooted desire of the poet is to win back his lost beloved.
(d) The eyes and voice are the two things praised in this poem.

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Maths Guide Pdf Chapter 2 Complex Numbers Ex 2.2 Textbook Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Maths Solutions Chapter 2 Complex Numbers Ex 2.2

Question 1.
Evaluate the following if z = 5 – 2i and w = -1 + 3i
(i) z + w
Solution:
z = 5 – 2i, w = -1 + 3i
z + w = (5 – 2i) + (-1 + 3i)
= (5 – 1) + (-2i + 3i)
= 4 + i

(ii) z – iw
Solution:
z – iw = (5 – 2i) – i (-1 + 3i)
= 5 – 2i + i + 3
= (5 + 3) + (-2i + i)
= 8 – i

(iii) 2z + 3w
Solution:
2z + 3w = 2(5 – 2i) + 3 (-1 +3i)
= 10 – 4i – 3 + 9i
= 7 + 5 i

(iv) zw
Solution:
zw = (5 – 2i) (-1 + 3i)
= -5 + 15i + 2i – 6i²
= -5 + 17i + 6
= 1 + 17i

(v) z² + 2zw + w²
Solution:
= (z + w)² [from (i)]
= (4 + i)²
= 16 – 1 + 8i
= 15 + 8i

(vi) (z + w)²
Solution:
(vi) (z + w)² = 15 + 8z [from (v)]

Question 2.
Given the complex number z = 2 + 3i, represent the complex numbers in the Argand diagram.
(i) z = 2 + 3i
iz = i(2 + 3i)
= (2i – 3)
= -3 + 2i
z + iz = (2 + 3i) + (-3 + 2i)
= -1 + 5i

(ii) z, – iz and z – iz
z = 2 + 3i
-iz = -i (2 + 3i)
= -2i – 3i² = -2i + 3
= 3 – 2i
z- iz= 2 + 3i -3 + 2i
= 5 + i

Question 3.
Find the values of the real numbers x and y. if the complex numbers
(3 – i)x – (2 – i) y + 2i + 5 and 2x + (-1 + 2i)y + 3 + 2i are equal.
Solution:
(3 – i) x – (2 – i) y + 2i + 5 = 2x + (-1 + 2i) y + 3 + 2i
⇒ 3x – ix – 2y + iy + 2i + 5 = 2x – y + 2yi + 3 + 2i
⇒ (3x – 2y + 5) + 1 (-x + y + 2) = (2x – y + 3) + i (2y + 2)
Equate real parts on both sides
3x – 2y + 5 = 2x – y + 3
x – y = -2 ……. (1)
Equate imaginary parts on both sides
-x + y + 2 = 2y + 2
-x – y = 0
x + y = 0 ……. (2)
(1) + (2) ⇒ 2x = -2
x = -1
Substituting x = -1 in (2)
-1 + y = 0
⇒ y = 1
∴ x = -1, y = 1

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Maths Guide Pdf Chapter 1 Applications of Matrices and Determinants Ex 1.8 Textbook Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Maths Solutions Chapter 1 Applications of Matrices and Determinants Ex 1.8

Choose the Most Suitable Answer.

Question 1.
If |adj(adj A) |=| A|⁹, then the order of the square matrix A is:
(a) 3
(b) 4
(c) 2
(d) 5
Solution:
(b) 4
Hint:
Since |adj(adj A)| = |A|^{(n – 1)2}
(n – 1)² = 9 = 3²
n – 1 = 3
n = 4

Question 2.
If A is a 3 × 3 non-singular matrix such that AA^T = A^T A and B = A^-1A^T, then BB^T =
(a) A
(b) B
(C) I₃
(d) B^T
Solution:
(C) I
Hint:
AA^T = A^TA and B = A^-1A^T
B^T = (A^-1)^T(A^T)^T = (A^-1)^T A
BB^-1 = (A^-1 A^T) (A^-1)^T A = A^-1 (AA^-1)^T A
= A^-1 (I)^T A = A^-1 A = I₃

Question 3.
If A = \(\begin{bmatrix} 3 & 5 \\ 1 & 2 \end{bmatrix}\) B = adj A and C = 3A, then \(\frac{|adj B|}{|C|}\) =
(a) \(\frac{1}{3}\)
(b) \(\frac{1}{9}\)
(C) \(\frac{1}{4}\)
(d) 1
Solution:
(a) \(\frac{1}{3}\)
Hint:

Question 4.
If A \(\begin{bmatrix} 1 & -2 \\ 1 & 4 \end{bmatrix}\) = \(\begin{bmatrix} 6 & 0 \\ 0 & 6 \end{bmatrix}\), then A:

Solution:
(c) \(\begin{bmatrix} 4 & 2 \\ -1 & 1 \end{bmatrix}\)
Hint:

Solve the equations we get
a = 4, b = 2, c = -1, d = 1
A = \(\begin{bmatrix} 4 & 2 \\ -1 & 1 \end{bmatrix}\)

Question 5.
If A = \(\begin{bmatrix} 7 & 3 \\ 4 & 2 \end{bmatrix}\) then 9I₂ – A =
(a) A^-1
(b) \(\frac{A^{-1}}{2}\)
(c) 3A^-1
(d) 2A^-1
Solution:
(d) 2A^-1
Hint:
|A| = 14 – 12 = 2

Question 6.
If A = \(\begin{bmatrix} 2 & 0 \\ 1 & 5 \end{bmatrix}\) and B = \(\begin{bmatrix} 1 & 4 \\ 2 & 0 \end{bmatrix}\) then |adj (AB)| =
(a) -40
(b) -80
(c) -60
(d) -20
Solution:
(b) -80
Hint:

∴ |adj (AB)| = 8 – 88 = -80

Question 7.
If P = \(\left[ \begin{matrix} 1 & x & 0 \\ 1 & 3 & 0 \\ 2 & 4 & -2 \end{matrix} \right] \) is the adjoint of 3 × 3 matrix A and |A| = 4, then x is
(a) 15
(b) 12
(c) 14
(d) 11
Solution:
(d) 11
Hint:
Since |adj A| = |A|^{n – 1} (n = 3)
1(-6 + 0) – x(-2) = 4²
-6 + 2x = 16
2x = 16 + 6 = 22
x = 11

Question 8.

(a) 0
(b) -2
(c) -3
(d) -1
Solution:
(d) -1
Hint:

Question 9.
If A, B and C are invertible matrices of some order, then which one of the following is not true?
(a) adj A = |A|A^-1
(b) adj (AB) = (adj A)(adj B)
(c) det A^-1 = (det A)^-1
(d) (ABC)^-1 = C^-1B^-1A^-1
Solution:
(b) adj (AB) = (adj A)(adj B)
Hint:
adj (AB) ≠ (adj A)(adj B)

Question 10.

Solution:
(a) \(\begin{bmatrix} 2 & -5 \\ -3 & 8 \end{bmatrix}\)
Hint:
(AB)^-1 = B^-1 A^-1
(AB)^-1 A = B^-1 [A^-1]A
(AB)^-1 A = B^-1
(A^-1)^-1 = A
|A^-1| = 3 – 2 = 1

Question 11.
If A^TA^-1 is symmetric, then A² =
(a) A^-1
(b) (A^T)²
(c) A^T
(d) (A^-1)²
Solution:
(b) (A^T)²
Hint:
(A^T A^-1)^T = A^T A^-1
(A^-1)^T (A^T)^T = A^T A^-1
(A^-1)^T A = A^T A^-1
A^T (A^-1)^T AA = (A^T) A^T A^-1 A
(pre and post multiply by A^T and A)
A² = (A^T)²

Question 12.
If A is a non-singular matrix such that A^-1 = \(\begin{bmatrix} 5 & 3 \\ -2 & -1 \end{bmatrix}\), then (AT)^-1 =

Solution:
(d) \(\begin{bmatrix} 5 & -2 \\ 3 & -1 \end{bmatrix}\)
Hint:
A^-1 = \(\begin{bmatrix} 5 & 3 \\ -2 & -1 \end{bmatrix}\)
Since (A^T)^-1 = (A^-1)^T = \(\begin{bmatrix} 5 & -2 \\ 3 & -1 \end{bmatrix}\)

Question 13.

(a) \(\frac{-4}{5}\)
(b) \(\frac{-3}{5}\)
(c) \(\frac{3}{5}\)
(d) \(\frac{4}{5}\)
Solution:
(a) \(\frac{-4}{5}\)
Hint:
Since A^T = A^-1
AA^T =  I

Question 14.

(a) (cos² \(\frac{θ}{2}\))A
(b) (cos² \(\frac{θ}{2}\))A^T
(c) (cos²θ)I
(d) (sin² \(\frac{θ}{2}\))A
Solution:
(b) (cos² \(\frac{θ}{2}\))A^T
Hint:

Question 15.

(a) 0
(b) sin θ
(c) cos θ
(d) 1
Solution:
(d) 1
Hint:

cos² θ + sin² θ = k
Hence k = 1

Question 16.
If A = \(\begin{bmatrix} 2 & 3 \\ 5 & -2 \end{bmatrix}\) be such that λA^-1 = A, then λ is:
(a) 17
(b) 14
(c) 19
(d) 21
Solution:
(c) 19
Hint:
λA^-1 = A

⇒ λ = 19

Question 17.
If adj A = \(\begin{bmatrix} 2 & 3 \\ 4 & 1 \end{bmatrix}\) and adj B = \(\begin{bmatrix} 1 & -2 \\ -3 & 1 \end{bmatrix}\) then adj (AB) is:

Solution:
(b) \(\begin{bmatrix} -6 & 5 \\ -2 & -10 \end{bmatrix}\)
Hint:
adj (AB) = (adj B) (adj A)

Question 18.

(a) 1
(b) 2
(c) 4
(d) 4
Solution:
(a) 1
Hint:

∴ Number of non zero row = 1
ρ(A) = 1

Question 19.

(a) \(e^{(Δ_{2}/Δ_{1})}\), \(e^{(Δ_{3}/Δ_{1})}\)
(b) log(Δ₁/Δ₃), log(Δ₂/Δ₃)
(c) log(Δ₂/Δ₁), log(Δ₃/Δ₁)
(d) \(e^{(Δ_{1}/Δ_{3})}\), \(e^{(Δ_{2}/Δ_{3})}\)
Solution:
(d) \(e^{(Δ_{1}/Δ_{3})}\), \(e^{(Δ_{2}/Δ_{3})}\)
Hint:
x^ay^b = e^m
a log x + b log y = m
x^cy^d = eⁿ
c log x + d log y = n

Question 20.
Which of the following is/are correct?
(i) Adjoint of a symmetric matrix is also a symmetric matrix.
(ii) Adjoint of a diagonal matrix is also a diagonal matrix.
(iii) If A is a square matrix of order n and λ is a scalar, then adj(λA) = λⁿ adj (A).
(iv) A(adj A) = (adj A)A = |A|I
(a) Only (i)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i), (ii) and (iv)
Solution:
(d) (i), (ii) and (iv)

Question 21.
If ρ(A) ρ([A | B]), then the system AX = B of linear equations is:
(a) consistent and has a unique solution
(b) consistent
(c) consistent and has infinitely many solutions
(d) inconsistent
Solution:
(b) consistent
Hint:
If ρ(A) = ρ[A|B] = no. of unknowns
We say consistent an unique solutions
Hence ρ(A) = ρ[A|B] ← given

Question 22.
If 0 ≤ θ ≤ π and the system of equations x + (sin θ)y – (cos θ)z = 0, (cos θ) x – y + z = 0, (sin θ) x + y + z = 0 has a non-trivial solution then θ is:
(a) \(\frac{2π}{3}\)
(b) \(\frac{3π}{4}\)
(c) \(\frac{5π}{6}\)
(d) \(\frac{π}{4}\)
Solution:
(d) \(\frac{π}{4}\)
Hint:
If AX = 0 has non  trivial solution if |A| = 0

⇒ 1(1 – 1) – sinθ (-cosθ – sinθ) – cosθ (cosθ + sinθ) = 0
⇒ + sinθ cosθ + sin²θ – cos²θ – sinθ cosθ = 0
⇒ sin²θ – cos²θ = 0
⇒ sinθ = cosθ
θ =\(\frac{π}{4}\)

Question 23.

(a) λ = 7, µ ≠ -5
(b) λ = -7, µ = 5
(c) λ ≠ 7, µ ≠ -5
(d) λ = 7, µ = -5
Solution:
(d) λ = 7, µ = -5
Hint:
ρ(A) = ρ[A | B] = 2
λ – 7 = 0 and µ + 5 = 0
λ = 7, µ = -5

Question 24.

(a) 2
(b) 4
(c) 3
(d) 1
Solution:
(b) 4
Hint:
B = A^-1

Question 25.

Solution:
(a) \(\left[\begin{array}{rrr}
3 & -3 & 4 \\
2 & -3 & 4 \\
0 & -1 & 1
\end{array}\right]\)
Hint:
adj (adj A) = |A|^n-2 A = |A|² A
|A|= 3(-3 + 4) + 3(2) + 4 (-2)
= 3 + 6 – 8
= 1

Students can download 10th Social Science History Chapter 1 Outbreak of World War I and Its Aftermath Questions and Answers, Notes, Samacheer Kalvi 10th Social Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Social Science Solutions History Chapter 1 Outbreak of World War I and Its Aftermath

Samacheer Kalvi 10th Social Science Outbreak of World War I and Its Aftermath Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
What were the three major empires shattered by the end of First World War?
(a) Germany, Austria Hungary, and the Ottomans
(b) Germany, Austria-Hungary, and Russia
(c) Spain, Portugal and Italy
(d) Germany, Austria-Hungary, Italy
Answer:
(a) Germany, Austria Hungary, and the Ottomans

Question 2.
Where did the Ethiopian army defeat the Italian army?
(a) Delville
(b) Orange State
(c) Adowa
(d) Algiers
Answer:
(c) Adowa

Question 3.
Which country emerged as the strongest in East Asia towards the close of nineteenth century?
(a) China
(b) Japan
(c) Korea
(d) Mongolia
Answer:
(b) Japan

Question 4.
Who said “imperialism is the highest stage of capitalism”?
(a) Lenin
(b) Marx
(c) Sun Yat-sen
(d) Mao Tsetung
Answer:
(a) Lenin

Question 5.
What is the Battle of Marne remembered for?
(a) air warfare
(b) trench warfare
(c) submarine warfare
(d) ship warfare
Answer:
(b) trench warfare

Question 6.
Which country after the World War I took to a policy of isolation?
(a) Britain
(b) France
(c) Germany
(d) USA
Answer:
(a) Britain

Question 7.
To which country did the first Secretary General of League of Nations belongs?
(a) Britain
(b) France
(c) Dutch
(d) USA
Answer:
(a) Britain

Question 8.
Which country was expelled from the League of Nations for attacking Finland?
(a) Germany
(b) Russia
(c) Italy
(d) France
Answer:
(b) Russia

II. Fill in the blanks

1. Japan forced a war on China in the year ……………….
2. The new state of Albania was created according to the Treaty of ………………. signed in May 1913.
3. Japan entered into an alliance with England in the year ……………….
4. In the Balkans ………………. had mixed population.
5. In the battle of Tannenberg ………………. suffered heavy losses.
6. ………………. as Prime Minister represented France in Paris Peace Conference.
7. ………………. became Prime Minister leading a new coalition of liberals and moderate Socialists before Lenin established the Bolshevik government.
8. Locarno Treaty was signed in the year ………………..

Answers:

1. 1894
2. London
3. 1902
4. Macedonia
5. Russia
6. Clemenceau
7. Kerensky
8. 1925

III. Choose the correct statement

Question 1.
(i) Italy remained a neutral country when the World War broke out.
(ii) Italy was much disappointed over the peace settlement at Versailles.
(iii) The Treaty of Sevres was signed with Italy.
(iv) Italy was denied even small places such as Trieste, Istria and the south Tyrol.
(a) (i) and (ii) are correct
(b) (iii) is correct
(c) (iv) is correct
(d) (i), (iii) and (iv) are correct
Answer:
(a) (i) and (ii) are correct

Question 2.
(i) The Turkish Empire contained many non-Turkish people in the Balkans.
(ii) Turkey fought on the side of the central powers
(iii) Britain attacked Turkey and captured Constantinople
(iv) Turkey’s attempt to attack Suez Canal but were repulsed.
(a) (i) and (ii) are correct
(b) (i) and (Hi) are correct
(c) (iv) is correct
(d) (i), (ii) and (iv) are correct
Answer:
(d) (i), (ii) and (iv) are correct

Question 3.
Assertion (A): Germany and the United States were producing cheaper manufactured goods and capturing England’s markets.
Reason (R): Both the countries produced required raw material for their industries.
(a) Both A and R are correct
(b) A is right but R is not the correct reason
(c) Both A and R are wrong
(d) R is right but it has no relevance to A.
Answer:
(b) A is right but R is not the correct reason

Question 4.
Assertion (A): The first European attempts to carve out colonies in Africa resulted in bloody battles.
Reason (R): There was stiff resistance from the native population.
(a) Both A and R are correct
(b) A is right but R is not the correct reason
(c) Both A and R are wrong
(d) R is right but it has no relevance to A.
Answer:
(a) Both A and R are correct

IV. Match the following

Answers:
A. (iii)
B. (iv)
C. (ii)
D. (v)
E. (i)

V. Answer briefly

Question 1.
How do you assess the importance of Sino-Japanese War?
Answer:
Sino-Japanese war took place in the years 1894 – 1895. China was defeated in the war. Japan annexed the Liaotung peninsula with Port Arthur inspite of warning given by three great powers, Russia, Germany and France. By this Japan had proved that it was the strongest nation of the East – Asia.

Question 2.
Name the countries in the Triple Entente.
Answer:
Britain, France and Russia.

Question 3.
What were the three militant forms of nationalism in Europe?
Answer:
The three militant forms of nationalism were, England’s Jingoism, France’s Chauvinism and Germany’s Kultur.

Question 4.
What do you know of trench warfare?
Answer:
Trench warfare is a type of land warfare using occupied fighting lines consisting largely of military trenches, in which troops are well-protected from the enemy’s small arms fire and are substantially sheltered from artillery. It is a warfare in which opposing armed forces attack, counterattack, and defend from relatively permanent systems of trenches dug in the ground.

Question 5.
What was the role of Mustafa Kemal Pasha?
Answer:
When Britian attacked Turkey directly and tried to capture Constantinople, Turks put up a brave fight and Mustafa Kemal Pasha played a great role to win freedom for the country. He put an end to the sultanate and caliphate. He modernized it and changed it out for recognition.

Question 6.
Highlight the global influence of Russian Revolution?
Answer:
The Russian Revolution fired people’s imagination across the world. In many countries, communist parties were formed. The Russian communist government encouraged the colonies to fight for their freedom and gave all support to them. Debates over key issues, land reforms, social welfare, workers’ rights, and gender equality taking place in a global context.

Question 7.
List out any two causes for the failure of the League of Nations.
Answer:
League did not had the military power of its own , it could not enforce its decisions. Even though, it had world wide membership it become very much the center of European diplomacy.

VI. Answer all the questions given under each caption

Question 1.
Imperialism
(a) What do you know of monopoly capitalism?
(b) How did Japan emerge as an imperial power?
(c) Why did the industrial countries need colonies in the nineteenth century?
(d) What were the contrasts capitalism produced?
Answer:
(a) Capitalism based on the principle of free -trade without any control or regulation by the state is called monopoly Capitalism.
(b) Japan emerged as an imperial power by annexing the Liaotung peninsula with Port Arthur inspite of warning given by Russia, Germany and France.
(c) Because colonies acted as a market for surplus goods and vast supplies of raw materials.
(d) Capitalism produced extreme poverty and extreme wealth. Slum and skyscraper. Empire state and dependent exploited colony.

Question 2.
German Emperor

(a) What was the nature of Emperor Kaiser Wilhelm II of Germany?
Answer:
Emperor Kaiser Wilhelm II of Germany was ruthlessly assertive and aggressive. He proclaimed that Germany would be the leader of the world.

(b) What was the violent form of Germany called?
Answer:
It was called Germany’s Kultur.

(c) Why did Kaiser Wilhelm intervene in the Morocco affair?
Answer:
The British agreement with France over the latter’s interest in Morocco was consented by Germany. So Kaiser Wilhelm II of Germany intentionally recognised the independence of the Sultan and demanded an international conference to decide on the future of Morocco.

(d) What happened to Germany’s colonies in Africa?
Answer:
The German colonies in western and eastern Africa were attacked by the Allies. As these colonies were quite far off from Germany they could not receive any immediate help, and therefore had to surrender to the Allies.

Question 3.
Balkan Wars
(a) Why was Balkan League formed?
(b) What was the outcome of the first Balkan War?
(c) Who were defeated in this war?
(d) What was the name of the Treaty signed at the end of this second Balkan War?
Answer:
(a) To control Greece, Serbia, Bulgaria and Montenegro in succeeding Balkans from Turks, in March 1912 the Balkan League was formed.
(b) The Balkan League defeated the Turkish forces in the 1st Balkan war.
(c) Turkey and Bulgaria were defeated in this war.
(d) Treaty of Bucharest in August 1913.

VII. Answer the following in detail

Question 1.
Discuss the main causes of the First World War.
Answer:
The causes of the First World War are given below:

1. Formation of European alliances and counter alliances
2. Emergence of violent forms of nationalism in countries like England, France and Germany
3. Aggressive attitude of the German Emperor Kaiser Wilhelm II
4. Hostility of France towards Germany
5. Opportunity for imperial power politics in the Balkans
6. The Balkans wars
7. Immediate cause which included the assassination of Archduke Franz Ferdinand, nephew and heir to Franz Joseph, Emperor of Austria-Hungary, by Princip, a Bosnian Serb, on 28 June 1914.

Question 2.
Highlight the provisions of the Treaty of Versailles relating to Germany.
Answer:

1. All the central powers were directed to pay war indemnity especially Germany was to pay heavy amount for the losses suffered.
2. Germany had to pay 6,600 million pounds as per the Reparation Commission, but can be paid in installments.
3. The Germans should not have submarines and airforce, but can have a small navy and an army of one lakh men.
4. Austria and Germany separated and Austria was given independence.
5. All German colonies came under the mandated territories of League of nations.
6. Germany had to give up all her overseas possessions, rights and titles to the allies.
7. Germany surrendered Alsace-Lorraine to France.
8. She signed the Treaty of Brest-Litovsk with Russia and the treaty of Bucharest with Bulgaria.
9. Rhineland was to be occupied by the allies. East of Rhineland area was to be demilitarised.
10. Poland was recreated with a corridor to Baltic containing the port of Danzig of Germany.

Question 3.
Explain the course of the Russian Revolution under the leadership of Lenin.
Answer:

1. Lenin was in Switzerland when the revolution broke out in Russia. He wanted to continued revolution.
2. His slogan of “All power to the Soviets” soon won over the workers’ leaders. Devastated by war time shortages, the people were attracted by the slogan of ‘Bread, Peace and Land’.
3. In October Lenin persuaded the Bolshevik Central Committee to decide on immediate revolution. Trotsky prepared a detailed plan
4. On 7 November the key government buildings, including the Winter Palace, the Prime Minister’s headquarters, were seized by armed factory workers and revolutionary troops
5. On 8 November 1917a new Communist government was in office in Russia. Its head this time was Lenin. The Bolshevik Party was renamed the Russian Communist Party.

Question 4.
Estimate the work done by the League of Nations, pointing out the reasons for its failure?
Answer:

1. League of nations was formed in 1920 with the twin objective of avoiding war and to maintain peace in the world.
2. The main work done by the League was to solve the dispute arose between Sweden and Finland over the sovereignity of Aaland Island. It ruled that the island should go to Finland.
3. League solved the frontier dispute between Poland and Germany in upper Silesia.
4. When dispute arose between Greece and Bulgaria in 1925, Greece invaded Bulgaria and the League ordered a ceasefire.
5. League had been successful in signing the Locarno Treaty in 1925 by which Germany,France, Belgium, Great Britain and Italy mutually guaranteed peace in Western Europe.
6. The main reason for the failure of the League was Italy, Japan and Germany headed by dictators refused to be bound by the orders of the League and started violation and League rules.
7. When League condemned the violation, they withdrew their membership.
8. League did not had a military power of its own.
9. Though it had a world-wide membership, it became the center of European diplomacy.
10. The League remained a passive witness to events, issues and incidents of violations therefore finally dissolved in 1946.

VIII. Activity

Question 1.
Students can be taught to mark the places of battles and the capital cities of the countries that were engaged in the War.
Answer:
(a) Battles of I World war:
(i) Battle of Tannenberg
(ii) Battle of Marne
(iii) Battle of Gallipoli
(iv) Battle of Jutland
(v) Battle of Verdun
(vi) Battle of Passchendaele
(vii) Battle of Caporetto
(viii) Battle of Cambrai
(ix) Battle of the Somme.

(b) Capital cities of countries engaged in the IWW.
Central powers & Capital:
(i) Germany – Berlin
(ii) Austria – Vienna
(iii) Hungary – Budapest
(iv) Italy – Rome
(v) Ottoman Empire – Istanbul, Bursa, Edirne, Sogut
(vi) Bulgaria – Sofia
(vii) Tu rkey – An ka ra
Allies- Capital:
(i) Great Britain – London
(ii) France – Paris
(iii) Russia – Moscow
(iv) Italy – Rome
(v) United States – Washington D. C

Question 2.
An assignment or a project work on the role of Indian soldiers in different battle fields across the globe and the casualties they suffered during the War be attempted by the students.
Answer:
During the War, the Indian Army contributed a large number of divisions and independent brigades to the European, Mediterranean and the Middle East. The Indian Army fought against the German Empire in German East Africa and on the Western Front. Indian divisions were also sent to Egypt, Gallipoli and nearly 700,000 served in Mesopotamia against the Ottoman Empire. While some divisions were sent overseas others had to remain in India guarding the North West Frontier and on internal security and training duties.

In addition to the permanent divisions, the Indian Army also formed a number of independent brigades. As part of the Southern Army the Aden Brigade was stationed in the Aden Protectorate on the strategically important naval route from Europe to India, where there was limited fighting.

The Bannu Brigade, the Derajat Brigade and the Kohat Brigade were all part of the Northern Army and they were deployed along the North West Frontier. The South Persia Brigade was formed in 1915 at the start of the Persian Campaign to protect the Anglo- Persian oil installations in south Persia and the Persian Gulf.

On the outbreak of war, the Indian Army had 150,000 trained men and the Indian Government offered the services of two cavalry and two infantry divisions for service overseas. The force known as Indian Expeditionary Force A was attached to the British Expeditionary Force and the four divisions were formed into two army corps: an infantry Indian Corps and the Indian Cavalry Corps.

Indian Expeditionary Force B consisted of the 27th (Bangalore) Brigade from the 9th (Secunderabad) Division and an Imperial Service Infantry Brigade, a pioneer battalion, a mountain artillery battery and engineers were sent to Tanganyika with the task of invading German East Africa. Force C was formed from the Indian Army’s 29th Punjabis, together with half battalions from the Princely states of Jind, Bharatpur, Kapurthala and Rampur. The largest Indian Army force to serve abroad was the Indian Expeditionary Force D in Mesopotamia, under the command of Lieutenant-General Sir John Nixon.

Over one million Indian troops served overseas, of whom 62,000 died and another 67,000 were wounded. In total at least 74,187 Indian soldiers died during the War. Field-Marshal Sir Claude Auchinleck, Commander-in-Chief of the Indian Army from 1942, commented that the British “couldn’t have come through both wars [World War I and II] if they hadn’t had the Indian Army.”

IX. Map Work

Mark the following countries on the world map.

1. Great Britain
2. Germany
3. France
4. Italy
5. Morocco
6. Turkey
7. Serbia
8. Bosnia
9. Greece
10. Austria-Hungary
11. Bulgaria
12. Rumania

Timeline:

Samacheer Kalvi 10th Social Science Outbreak of World War I and Its Aftermath Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
The Treaty of serves was signed with:
(a) Austria
(b) Hungary
(c) Turkey
(d) Bulgaria
Answer:
(c) Turkey

Question 2.
The policy of imperialism followed by the European countries from 1870-1945 was known as ……
(a) New imperialism
(b) Military imperialism
(c) Neo-imperialism
Answer:
(a) New imperialism

Question 3.
President Woodrow Wilson put forward ………….. points in the League of nations.
(a) 12
(b) 11
(c) 10
(d) 14
Answer:
(d) 14

Question 4.
With a modem army and navy, ….. had emerged as an advanced industrialised
power.
(a) Germany
(b) Japan
(c) Italy
Answer:
(b) Japan

Question 5.
Germany surrendered in:
(a) 1917
(b) 1918
(c) 1919
(d) 1916
Answer:
(b) 1918

Question 6.
The ‘Sphere of influence’ was adopted by the European countries in ……
(a) Japan
(b) China
(c) India
Answer:
(b) China

Question 7
………….. is the name of the parliament of Russia.
(a) Tsar
(b) Trotsky
(c) Duma
(d) Rasputin.
Answer:
(c) Duma

Question 8.
The word “Imperialism” is derived from ……
(a) Greek
(b) German
(c) Latin
Answer:
(c) Latin

Question 9.
Nicholas II abdicated from his throne on ……………. 1917.
(a) March 12
(b) March 15
(c) November 18
(d) October 14
Answer:
(b) March 15

Question 10.
The development of ……. speeded the movements of goods between colonies and other countries.
(a) Roadways
(b) Waterways
(c) Railways
Answer:
(c) Railways

II. Fill in the blanks

1. The biggest outcome of the first world war was the …………….
2. The Trust is an industrial organisation in the …………….
3. The Imperialist Prime Minister of South Africa was called …………….
4. Cartel means ……………. of enterprises in the same field of business.
5. The treaty of ……………. was signed after the Russo-Japanese war and Japan got back port Arthur.
6. The violent form of nationalism in Germany was called as …………….
7. France and Germany were old …………….
8. The enemity between and led to the outbreak of war in 1914.
9. The new state of Albania was created according to the treaty of ……………. signed in 1913.
10. Russia suffered heavy loses in the battle of …………….
11. Trench warfare was the style followed in the battle of …………….
12. Russia signed the treaty of ……………. with Germany.
13. Italy formally joined the allies in …………….
14. Battle of Jutland is a ……………. battle.
15. ……………. is the name of the American ship sunk by Germany.
16. ……………. was one of the principle in the fourteen points of Paris peace conference.
17. The war conditions led to the ……………. movement in India.
18. ……………. modernised Turkey and changed it out of all recognition.
19. £ is the symbol of …………….
20. The Bolshevik party was renamed as ……………. party.

Answers:

1. Russian Revolution
2. USA
3. Cecil Rhodes
4. Association
5. Portsmouth
6. Kultur
7. Rivals
8. Austria and Serbia
9. London
10. Tannenburg
11. Marne
12. Brest Litovsk
13. 1916
14. Naval
15. Lusitania
16. Self determination
17. Home Rule
18. Pound sterling
19. Kemal Pasha
20. Russian communist

III. Choose the correct statements.

Question 1.
(i) The Industrial achievements of Germany in the later half of the 19th Century gave her a dominating position in Europe.
(ii) When Germany came to the scene of exploitation, it became weak in its military power.
(iii) When there was nowhere else to expand, imperialist countries grab other’s possession.
(iv) Russia, Britain and France joined in the scramble for colonies.
(a) (i) and (ii) are correct
(b) (i) and (iii) are wrong
(c) (ii) and (iv) are wrong
(d) (i), (ii) and (iv) are correct
Answer:
(c) (ii) and (iv) are wrong

Question 2.
(i) The Central powers consisted of Germany, Austria-Hungary, Turkey and Bulgaria.
(ii) Italy strongly supported Germany.
(iii) In April 1916, Britain, France and Italy signed the Treaty of London.
(iv) Italy agreed to enter the war against the central powers in-return of this territory after the war.
(a) (i), (ii) and (iii) are correct
(b) (ii), (iii) and (iv) are correct
(c) (i) and (iii) are correct
(d) (i) and (iv) are correct
Answer:
(d) (i) and (iv) are correct

Question 3.
(i) Trenches are ditches dug by troops enabled soldiers.
(ii) It was done to protect themselves from enemy fire.
(iii) The battle of Jutland is a memorable one for Trench war fare.
(iv) Trench system used in the first world war consisted of six to seven trench lines running parallel to each other.
(a) (ii) and (iv) are correct
(b) (i) and (ii) are correct
(c) (i) and (iv) are correct
(d) (iii) and (iv) are correct
Answer:
(b) (i) and (ii) are correct

Question 4.
(i) The main provision of the Versailles treaty was that all central powers were directed to pay war indemnity.
(ii) All the German colonies became mandated territories under the League of nations.
(iii) The Saar coal mine was given to Bulgaria.
(iv) Northern Schleswig was given to France.
(a) (iii) and (iv) are correct
(b) (i) and (ii) are correct
(c) (i), (ii), (iv) are correct
(d) (ii) and (iv) are correct
Answer:
(b) (i) and (ii) are correct

Question 5.
(i) Triple Alliance was signed in 1882 between Germany, Austria-Hungary and Italy.
(ii) Entente cordiale was signed in 1906 between Britain and Russia.
(iii) Triple Entente was signed between Britain, France and Russia.
(iv) The Britain violation of Belgian neutrality forced German to enter the war.
(a) (i), (ii), (iv) are correct
(b) (iii) and (iv) are correct
(c) (i) and (iii) are correct
(d) (ii) and (iv) are correct
Answer:
(c) (i) and (iii) are correct

IV. Assertion and Reason

Question 1.
Assertion (A): Inspite of warning of the three great powers, Russia, Germany and France, Japan annexed the Liaotung Peninsula with Port Arthur.
Reason (R): Japan proved that it was the strongest nation of the East Asia.
(a) Both A and R are correct
(b) A is right but R is not the correct reason
(c) Both A and R are wrong
(d) R is right but it has no relevant to A
Answer:
(a) Both A and R are correct

Question 2.
Assertion (A): Two peace conferences were held at the Hague in Holland in 1899 and in 1907.
Reason (R): Lenin of Russia wanted to bring Universal peace and suggested these conferences.
(a) Both A and R are correct
(b) A is right but R is not the correct reason
(c) Both A and R are wrong
(d) R is right but it has no relevant to A
Answer:
(b) A is right but R is not the correct reason

Question 3.
Assertion (A): Italy formally joined with the allies fighting with Austria, initially sustained, but finally collapsed.
Reason (R): Germans came to Austria’s help.
(a) Both A and R are correct
(b) A is right but R is not the correct reason
(c) Both A and R are wrong
(d) R is right but it has no relevant to A
Answer:
(a) Both A and R are correct

Question 4.
Assertion (A): In Germany and Austria, women and children suffered from hunger and privation.
Reason (R): Aeroplanes were used for bombing targeted Civilian population.
(a) Both A and R are correct
(b) A is right but R is not the correct reason
(c) Both A and R are wrong
(d) R is right but it has no relevant to A
Answer:
(b) A is right but R is not the correct reason

Question 5.
Assertion (A): Marxists in Russia had the fortune of getting Lenin as their leader.
Reason (R): Tsar Nicholas li was under the strong influence of his wife Alexandra.
(a) Both A and R are correct
(b) A is right but R is not the correct reason
(c) Both A and R are wrong
(d) R is right but it has no relevant to A
Answer:
(b) A is right but R is not the correct reason

Question 6.
Assertion (A): The League of nations could apply the principle of collective security.
Reason (R): It was supported by Italy, Japan and Germany.
(a) Both A and R are correct
(b) A is right but R is not the correct reason
(c) Both A and R are wrong
(d) R is right but it has no relevant to A
Answer:
(c) Both A and R are wrong

V. Match the following

Question 1.
Match the Column I with Column II.

Answer:
A. (iv)
B. (v)
C. (i)
D. (ii)
E. (iii)

Question 2.
Match the column I with column II.

Answer:
A. (iv)
B. (i)
C. (v)
D. (ii)
E. (iii)

VI. Answer the following questions briefly

Question 1.
What was the aim of the capitalist countries?
Answer:
The aim of the capitalistic countries was to produce more and more. The surplus wealth that was produced was used to build more factories, railways, steamship and other such undertakings.

Question 2.
What is colonialism?
Answer:
(i) Colonialism refers to the policy of acquiring and maintaining colonies especially for exploitation.
(ii) It also means that it is a relationship between an indigenous majority and a minority foreign invaders.

Question 3.
What was the immediate cause of the first world war?
Answer:
The nephew and heir to Franz Joseph, Emperor of Austria-Hungary. The Arch duke Franz Ferdinand was killed by Princip a Serbian of Bosnia. This was the immediate cause as Austria got help from Germany and Serbia got help from Russia. Thus the war began in 1914.

Question 4.
How did China became an International colony?
Answer:

1. The Boers were defeated by foreign powers.
2. When they reached Peking, the capital of China, Empress Dowager fled from the capital,
3. The U.S.A. and England formulated the Open Door Policy or Me Too Policy.
4. The Chinese territories were partitioned among the foreign powers for trade rights. Thus China became an international colony.

Question 5.
What do you understand by Paris peace conference?
Answer:
The Paris peace conference held in January 1919 two months after the signing of the armistice.
Woodrow Wilson of America and Lloyd George of Britain were the important personalities. On 28 June 1919, the peace treaty was signed in The Hall of Mirrors at Versailles.

Question 6.
What was the immediate cause of the First World War?
Answer:

1. In 1908, Austria annexed Bosnia and Herzegovina against the Congress of Berlin.
2. Austrian Prince Francis Ferdinand and his wife were assassinated at Sarajevo on June 28, 1914.
3. Austria sent an ultimatum to Serbia, but Serbia ignored it.
4. So Austria declared war on Serbia on 28th July 1914.

Question 7.
Write the slogans raised by Lenin that attracted soviet people.
Answer:
“All power to the soviets” and “Bread, Peace and Land” were the slogans raised by Lenin that attracted the soviet people who were devastated by war time shortages.

Question 8.
Write any two terms of the Treaty of Versailles.
Answer:

1. A huge war indemnity was imposed on Germany. Her army was reduced.
2. The overseas possessions of Germany were divided among the victorious nations.

Question 9.
Write any two objectives of the League.
Answer:
The two main objective of the League of Nations was (i) To avoid war and to maintain peace in the world, (ii) To promote international co-operation in economic and social affairs.

Question 10.
What do you mean by Russian Revolution?
Answer:
The fall of monarch in February 1917 and the events of October are known as the Russian Revolution.

Question 11.
What is Duma? Why did the Tsar dismiss the first Duma within 75 days of its election?
Answer:
An elective legislative assembly established in 1905 by Nicholas II in Russia is known as Duma. Because the Tsar did not want anyone to question his authority, so he dismissed the first Duma within 75 days.

VII. Answer all the questions given under each caption

1. Characteristics of Imperialism

(a) What led to concept of Imperialism?
Answer:
Capitalism inevitably led to the concept of Imperialism.

(b) What was Lenin idea on Imperialism?
Answer:
According to Lenin, imperialism is the highest stage of Capitalism.

(c) What were the purposes for which the colonies were made use of?
Answer:
The colonies served as a market for goods and also vast suppliers of raw materials like cotton, Rubber etc.

(d) What was the logic behind Imperialism apart from colonisation?
Answer:
The logic behind Imperialism apart from colonisation was, total militarisation and total war.

2. The ambition of Germany

(а) Who was the ruler of Germany during the First World War?
Answer:
Kaiser Wilhelm II.

(b) What did he believe?
Answer:
He believed that Germany alone was competent to rule the whole world.

(c) What could not be tolerated by him?
Answer:
He could not tolerate the British saying that the Sun never sets in the British Empire.

3. Naval Battles

(a) Name the Naval battle that took place in 1916?
Answer:
In 1916, the Naval battle had taken place in the North sea called as Battle of Jutland.

(b) Which country started the Sub-marine warfare thereafter?
Answer:
Germany started their Submarine warfare thereafter.

(c) Name the ship that bombarded Madras?
Answer:
The ship that bombarded Madras was the famous Emden ship.

(d) Name the American ship torpedoed by a German Submarine.
Answer:
Lusitania, an American ship was torpedoed by a German Submarine.

4. Course of the First World War

(a) Give the duration of the First World War.
Answer:
From July 28, 1914 to November 11, 1918.

(b) Who were called the Central Powers?
Answer:
The countries which were on the side of Germany were called the Central Powers.

(c) Who were called the Allies?
Answer:
The countries which were on the side of Britain were called as the Allies.

(d) What and all were used in war?
Answer:
Artillery, Tanks and submarines were used in the war.

5. Lenin

(a) Where was he born?
Answer:
Lenin was bom in 1870 near the middle Volga to educated parents.

(b) What was his belief?
Answer:
Lenin believed that the wav for freedom was through mass action.

(c) When and why was he arrested?
Answer:
He was arrested in 1895 and kept in Serbia for encouraging the ideas of Marxism to the factory workers in St. Petersburg.

(d) How did he form the Bolshevik party?
Answer:
Lenin gained the support of small majority called Bolshmstvo known as Bolsheviks which later became the Bolshevik party.

6. Results of the war

(a) How were the terms of the treaties drafted?
Answer:
Based upon the fourteen points of the American President Woodrow Wilson.

(b) What did Germany surrendered to France?
Answer:
Germany surrendered Alsace and Lorraine to Europe.

(c) Where was monarchy abolished?
Answer:
In Germany, Russia, Austria and Turkey.

(d) Name the new Republics.
Answer:
Czechoslovakia and Poland.

VIII. Answer the following in detail

Question 1.
Write a note on the structure and composition of its League of Nations.
Answer:

1. The covenant of the League of Nations was formed at the Paris peace conference after the first world war.
2. President of USA -Woodrow Wilson largely supported for this task to be accomplished.
3. The structure of the League consist of the Assembly, the council, the Secretariat, the permanent court of Justice and the International Labour organization.
4. Each member country was represented in the Assembly.
5. Each member country’ and had one vote and also possessed the right of veto.
6. Britain, France, Italy, Japan and United States were originally declared permanent members of the council.
7. The council was the executive of the League.
8. The staff of the secretariat was appointed by the Secretary General in consultation with the council.
9. The court of Justice consisted of fifteen Judges.
10. The International Labour organization comprised a Secretariat. The general conference will include four representatives from each country.
11. The first secretary general of League of Nations was Sir Eric Drummond from Britain.

Question 2.
What were the results of the first world war?
Answer:
The Paris Peace Conference:

1. The first world war came to an end by the Paris Peace Conference of 1919.
2. The city of Danzig was internationlized.
3. Lithuvania, Latvia and Estonia were granted independence.

The formation of the League of Nations:

1. The first world war brought untold miseries to people.
2. All the nations wanted a permanent body to maintain peace in the world. So the League of Nations was formed in 1920.
3. The victorious nations forced the defeated nations with unfair treaties. It sowed the seed for the second world war.

Question 3.
What was the impact of First world war on India?
Answer:

1. The first world war had multiple effects on the Indian economy, society and politics.
2. Indians had taken an active part in the war on the side of Britain, believing that they would reward Independence after the war.
3. But also, disappointment was rewarded to the Indians.
4. Indian soldiers asked to serve in Europe, Africa and West Asia.
5. India contributed £230 million in cash and over £125 million in loan towards war expenses.
6. India also sent war materials to the value of £ 250 million .
7. There were economic distress all over the country.
8. Towards the end of the war, India suffered under the world wide epidemic of influenza.
9. Home Rule Movement arose in India due to the war conditions.
10. The congress split of extremists and moderates reunited.
11. The Ottoman Empire under the Turkish Sultan was defeated in World war I and the territories shared between Britain and France.
12. This led to the formation of Khilafat Movement in India.

Students can download Maths Chapter 6 Trigonometry Additional Questions and Answers, Notes, Samacheer Kalvi 10th Maths Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Maths Solutions Chapter 6 Trigonometry Additional Questions

I. Multiple Choice Questions

Question 1.
(1 – sin² θ) sec² θ = …………
(1) 0
(2) 1
(3) tan² θ
(4) cos² θ
Answer:
(2) 1
Hint: (1 – sin² θ) sec² θ = cos² θ sec² θ = cos² θ \(\frac{1}{\cos ^{2} \theta}\) = 1

Question 2.
(1 + tan² θ) sin² θ = ………….
(1) sin² θ
(2) cos² θ
(3) tan² θ
(4) cot² θ
Answer:
(3) tan² θ
Hint: (1 + tan² θ) sin² θ = sec² θ sin² θ = \(\frac{1}{\cos ^{2} \theta}\) sin² θ = \(\frac{\sin ^{2} \theta}{\cos ^{2} \theta}\) = tan² θ

Question 3.
(1 – cos² θ) (1 + cot² θ) = ………..
(1) sin² θ
(2) 0
(3) 1
(4) tan² θ
Answer:
(3) 1
Hint: (1 – cos² θ) (1 + cot² θ) = sin² θ cosec² θ = sin² θ. \(\frac{1}{\sin ^{2} \theta}\)= 1

Question 4.
sin (90° – θ) cos θ + cos (90° – θ) sin θ = …………..
(1) 1
(2) 0
(3) 2
(4) -1
Answer:
(1) 1
Hint: sin (90° – θ) cos θ + cos (90° – θ) sin θ = cos θ cos θ + sin θ sin θ = cos² θ + sin² θ = 1

Question 5.
1 – \(\frac{\sin ^{2} \theta}{1+\cos \theta}\) = ……………….
(1) cos θ
(2) tan θ
(3) cot θ
(4) cosec θ
Answer:
(1) cos θ
Hint:

Question 6.
cos⁴ x – sin⁴ x = ……………
(1) 2 sin² x – 1
(2) 2 cos² x – 1
(3) 1 + 2 sin² x
(4) 1 – 2 cos² x
Answer:
(2) 2 cos² x – 1
Hint:
cos⁴ x – sin⁴ x (cos² x)² – (sin² x)²
= (cos² x + sin²x) (cos² x – sin²x)
= 1 (cos² x – sin² x)
= cos² x – (1 – cos² x)
cos² x – 1 + cos² x
= 2 cos² x – 1.

Question 7.
If tan θ = \(\frac { a }{ x } \) , then the value of \(\frac{x}{\sqrt{a^{2}+x^{2}}}\) = ………………
(1) cos θ
(2) sin θ
(3) cosec θ
(4) sec θ
Answer:
(1) cos θ
Hint:

Question 8.
If x = a sec θ, y = b tan θ, then the value of \(\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}\) = ………………..
(1) 1
(2) -1
(3) tan² θ
(4) cosec² θ
Answer:
(1) 1
Hint:

Question 9.
\(\frac{\sec \theta}{\cot \theta+\tan \theta}\) = ………..
(1) cot θ
(2) tan θ
(3) sin θ
(4) – cot θ
Answer:
(3) sin θ
Hint:

Question 10.

Answer:
(1) tan θ
(2) 1
(3) -1
(4) sin θ
Answer:
(2) 1
Hint:

Question 11.
In the adjoining figure, AC = ………….

(1) 25m
(2) 25 \(\sqrt { 3 }\) m
(3) \(\frac{25}{\sqrt{3}}\)
(4) 25 \(\sqrt { 2 }\) m
Answer:
(2) 25 \(\sqrt { 3 }\) m
Hint:
tan θ = \(\frac { AC }{ AB } \) ⇒ tan 60° = \(\frac { AC }{ 25 } \) ⇒ AC = 25 \(\sqrt { 3 }\) m

Question 12.
In the adjoining figure ∠ABC =

(1) 45°
(2) 30°
(3) 60°
(4) 50°
Answer:
(3) 60°
Hint:
tan B = \(\frac { AC }{ AC } \) = \(\frac{100 \sqrt{3}}{100}\) = \(\sqrt { 3 }\) ⇒ ∴ tan B = \(\sqrt { 3 }\) ⇒ ∠B = 60°

Question 13.
A man is 28.5 m away from a tower. His eye level above the ground is 1.5 m. The angle of elevation of the tower from his eyes is 45°. Then the height of the tower is …………..
(1) 30 m
(2) 27.5 m
(3) 28.5 m
(4) 27 m
Answer:
(1) 30 m
Hint:
tan 45° = \(\frac { AB }{ BC } \)

1 = \(\frac { x }{ 28.5 } \) ⇒ x = 28.5
Height of tower = 28.5 + 1.5 = 30 m

Question 14.
In the adjoining figure, sin θ = \(\frac { 15 }{ 17 } \) Then BC = ………….
(1) 85 m
(2) 65 m
(3) 95 m
(4) 75 m
Answer:
(4) 75 m
Hint:
sin θ = \(\frac { BC }{ AC } \) ⇒ \(\frac { 15 }{ 17 } \) = \(\frac { BC }{ 85 } \) ⇒ BC = \(\frac{85 \times 15}{17}\) = 75 m

Question 15.
(1 + tan² θ) (1 – sin θ) (1 + sin θ) = …………..
(1) cos² θ – sin² θ
(2) sin² θ – cos² θ
(3) sin² θ + cos² θ
(4) 0
Answer:
(3) sin² θ + cos² θ
Hint:
(1 + tan² θ) (1 – sin θ) (1 + sin θ) = (1 + tan² θ) (1 – sin² θ) = sec² θ × cos² θ = sec² θ × cos² θ = sec² θ × \(\frac{1}{\sec ^{2} \theta}\) = 1 = sin² θ + cos² θ

Question 16.
(1 + cot² θ) (1 – cos θ) (1 + cos θ) = ………………….
(1) tan² θ – sec² θ
(2) sin² θ – cos² θ
(3) sec² θ – tan² θ
(4) cos² θ – sin² θ
Answer:
(3) sec² θ – tan² θ
Hint:
(1 + cot² θ) (1 – cos θ) (1 + cos θ) = (1 + cot² θ) (1 – cos² θ) = cosec² θ. sin² θ
= \(\frac{1}{\sin ^{2} \theta}\) sin² θ = 1 = sec² θ – tan² θ.

Question 17.
(cos² θ – 1) (cot² θ + 1) + 1 = ……………….
(1) 1
(2) -1
(3) 2
(4) 0
Answer:
(4) 0
Hint:
(cos² θ – 1) (cot² θ + 1) + 1 = – sin² θ (cosec² θ) + 1 = – sin² θ \(\frac{1}{\sin ^{2} \theta}\) + 1 = -1 + 1 = 0

Question 18.
\(\frac{1+\tan ^{2} \theta}{1+\cot ^{2} \theta}\) = …………….
(1) cos² θ
(2) tan² θ
(3) sin² θ
(4) cot² θ
Answer:
(2) tan² θ
Hint:

Question 19.
Sin² θ + \(\frac{1}{1+\tan ^{2} \theta}\) …………
(1) cosec² θ + cot² θ
(2) cosec² θ – cot² θ
(3) cot² θ – cosec² θ
(4) sin² θ – cos² θ
Answer:
(2) cosec² θ – cot² θ
Hint:
sin² θ + \(\frac{1}{1+\tan ^{2} \theta}\) = sin² θ + \(\frac{1}{\sec ^{2} \theta}\) = sin² θ + cos² θ = 1 cosec² θ – cot² θ

Question 20.
9 tan² θ – 9 sec² θ = ……..
(1) 1
(2) 0
(3) 9
(4) -9
Answer:
(4) -9
Hint:
9 tan² θ – 9 sec² θ = 9(tan² θ – sec² θ) = 9(-1) = -9

Question 21.
The length of shadow of a tower on the plane ground is \(\sqrt { 3 }\) times the height of the tower. The angle of elevation of sum is …………..
(1) 45°
(2) 30°
(3) 60°
(4) 90°
Ans.
(2) 30°
Hint: Let the height of the tower be “x”
Lenght of the shadow is \(\sqrt { 3 }\) x

In the right ∆ ABC, tan θ = \(\frac{\mathrm{AB}}{\mathrm{BC}}=\frac{x}{\sqrt{3} x}=\frac{1}{\sqrt{3}}\)
= tan 30°
θ = 30°

Question 22.
A ladder makes an angle of 60° with the ground, when placed against a wall. If the foot of the ladder is 2m away from the wall, then the length of the ladder (in metres) is …………
(1) \(\frac{4}{\sqrt{2}}\) m
(2) 4 \(\sqrt { 3 }\) m
(3) 2 \(\sqrt { 2 }\) m
(4) 4 m
Answer:
(4) 4 m
Hint:
Let the length of the ladder be x.

In ∆ ABC, cos 60° = \(\frac { BC }{ AC } \) = \(\frac { 2 }{ x } \)
\(\frac { 1 }{ 2 } \) = \(\frac { 2 }{ x } \) ⇒ x = 4m

Question 23.
The angle of depression of a car parked on the road from the top of a 150m high tower is 30°. The distance of the car from the tower (in metres) is ……….
(1) 150 \(\sqrt { 3 }\) m
(2) 150 \(\sqrt { 2 }\)
(3) 75 cm
(4) 50 \(\sqrt { 3 }\) m
Answer:
(4) 50 \(\sqrt { 3 }\) m
Hint:
Let the distance of the car from the tower is “x” m
In ∆ ABC, tan 30° = \(\frac { AB }{ BC } \)

\(\frac{1}{\sqrt{3}}\) = \(\frac { 150 }{ x } \) ⇒ x = 150 \(\sqrt { 3 }\) m

Question 24.
The angle of elevation of the top of a tower at a point on the ground 50 m away from the foot of the tower is 45°. Then the height of the tower (in meters) is ……….
(1) 50 \(\sqrt { 3 }\) m
(2) 50 m
(3) \(\frac{50}{\sqrt{2}}\) m
(4) \(\frac{50}{\sqrt{3}}\) m
Answer:
(4) \(\frac{50}{\sqrt{3}}\) m
Hint:
Let the height of the AB be “x”
On ∆ ABC
tan 45° = \(\frac { AB }{ BC } \)

1 = \(\frac { x }{ 50 } \) ⇒ x = 50 m

Question 25.
If x = a cos θ and y = b sin θ, then b²x² + a²y² = ……………
(1) a²b²
(2) ab
(3) a4b4
(4) a² + b²
Answer:
(1) a²b²
Hint:
b²a² cos² θ + a² b² sin² θ = a²b² (cos² θ + sin² θ) = a²b² × 1 = a²b²

II. Answer The Following Questions.

Question 1.
Prove that sec² θ + cosec² θ = sec² θ cosec² θ
Answer:
L.H.S = sec² θ + cosec² θ

Question 2.
Prove that \(\frac{\sin \theta}{1-\cos \theta}\) = cosec θ + cot θ.
Answer:

Question 3.
Prove that \(\frac{\cos \theta}{\sec \theta-\tan \theta}\) = 1 + sin θ
Answer:

= 1 + sin θ = R.H.S
L.H.S = R.H.S

Question 4.
Prove that sec θ (1 – sin θ) (sec θ + tan θ) = 1
Answer:
L.H.S = sec θ (1 – sin θ) (sec θ + tan θ)

Question 5.
Prove that \(\frac{\sin \theta}{\csc \theta+\cot \theta}=1\) – cos θ
Answer:

Question 6.
Prove the identify \(\frac{\sin \theta}{\csc \theta}+\frac{\cos \theta}{\sec \theta}=1\)
Answer:

Question 7.
Prove the identify \(\sqrt{\frac{1-\cos \theta}{1+\cos \theta}}\) = cosec θ – cot θ
Answer:

(∵ 1 – cos² θ = sin² θ)
L.H.S = R.H.S

Question 8.
Prove the identity [cosec (90° – θ) – sin (90° – θ)] [cosec θ – sin θ] [tan θ + cot θ] = 1
Answer:
Now, [cosec (90° – θ) – sin (90° – θ)] [cosec θ – sin θ] [tan θ + cot θ]

Question 9.
A kite is flying with a string of length 200 m. If the thread makes an angle 30° with the ground, find the distance of the kite from the ground level. (Here, assume that the string is along a straight line.)
Answer:
Let h denote the distance of the kite from the ground level.
In the figure, AC is the string
Given that ∠CAB = 30° and AC = 200 m.
In the right ∆ CAB,
sin 30 = \(\frac { BC }{ AC } \)

sin 30 = \(\frac { h }{ 200 } \)
⇒ h = 200 sin 30°
∴ h = 200 × \(\frac { 1 }{ 2 } \) = 100 m
Hence the distance of the kite from the ground level is 100 m.

Question 10.
Find the angular elevation (angle of elevation from the ground level) of the Sun when the length of the shadow of a 30 m long pole is 10 \(\sqrt { 3 }\) m.
Answer:
Let S be the position of the Sun and BC be the pole.
Let AB denote the length of the shadow of the pole.
Let the angular elevation of the Sun be θ.
Given that AB = 10 \(\sqrt { 3 }\) m and BC = 30 m
In the right ∆ CAB,tan θ = \(\frac { BC }{ AB } \) = \(\frac{30}{10 \sqrt{3}}=\frac{3}{\sqrt{3}}\)
⇒ tan θ = \(\sqrt { 3 }\)
∴ θ = 60°
Thus, the angular elevation of the Sun from the ground level is 60°

Question 11.
A ramp for unloading a moving truck, has an angle of elevation of 30°. If the top of the ramp is 0.9 m above the ground level, then find the length of the ramp.
Answer:
Let AC be the length of the ramp and AC = “x” metre
In the right angled ∆ ABC,
∠A = 30° and BC = 0.9 m
sin 30° = \(\frac { BC }{ AC } \)

\(\frac { 1 }{ 2 } \) = \(\frac { 0.9 }{ x } \)
x = 0.9 × 2 = 1.8 m
∴ Length of the ramp x = 1.8 m

Question 12.
A girl of height 150 cm stands in front of a lamp-post and casts a shadow of length 150 \(\sqrt { 3 }\) cm on the ground. Find the angle of elevation of the top of the lamp-post.
Answer:
The height of the girl (BC) = 150 cm
Length of the shadow = 150 \(\sqrt { 3 }\) cm
Let θ be the angle of elevation of the lamp post.

In θ = \(\frac{150}{150 \sqrt{3}}\) = \(\frac{1}{\sqrt{3}}\)

tan 30° = \(\frac{1}{\sqrt{3}}\) ⇒ ∴ θ = 30°
∴ Angle of elevation of the lamp post = 30°

Question 13.
Prove that \(\sqrt{\cot ^{2} \theta-\cos ^{2} \theta}\) = cot θ . cos θ
Answer:

Question 14.
Prove that \(\frac{1+\sin \theta}{\cos \theta}+\frac{\cos \theta}{1+\sin \theta}\) = 2 sec θ
Answer:

Question 15.
A tower is 100 \(\sqrt { 3 }\) metres high. Find the angle of elevation of its top from a point 100 metres away from its foot.
Answer:
Let MN be the tower of height 100 \(\sqrt { 3 }\) m
“O” be the point of observation such that OM = 100 m

Let 0 be the angle of elevation
In the right ∆ OMN, we have
tan θ = \(\frac { MN }{ OM } \) = \(\frac{100 \sqrt{3}}{100}\)
tan θ = \(\sqrt { 3 }\) = tan 60°
∴ θ = 60°
Hence the angle of elevation is 60°

Question 16.
If sin θ = x and sec θ = y, then find the value of cot θ
Answer:
Given sin θ = x
y = sec θ = \(\frac{1}{\cos \theta}\)
∴ cos θ = \(\frac { 1 }{ y } \) ⇒ cot θ = \(\frac{\cos \theta}{\sin \theta}=\frac{1}{y} \div x\)
cot θ = \(\frac { 1 }{ xy } \)

Question 17.
A circus artist is climbing a 20 m long rope, which is tightly stretched and tied from the top of a vertical pole to the ground. Find the height of the pole, if the angle made by the rope with the ground level is 30° ( see figure).
Answer:
In the figure, let AC is the rope and AB is the pole. In right ∆ ABC, we have
\(\frac { AB }{ AC } \) = sin 30°
But, sin 30° = \(\frac { 1 }{ 2 } \)
\(\frac { AB }{ AC } \) = \(\frac { 1 }{ 2 } \) ⇒ \(\frac { AB }{ 20 } \) = \(\frac { 1 }{ 2 } \)
[∵ AC = 20 m]

AB = 20 × \(\frac { 1 }{ 2 } \) = 10 m
Thus, the required height of the pole is 10 m.

Question 18.
A kite is flying at a height of 60 m above the ground. The string attached to the kite is temporarily tied to a point on the ground. The inclination of the string with the ground is 60°. Find the length of the string, assuming that there is no slack in the string.
Answer:
Let in the right ∆ AOB,
OB = Length of the string
AB = 60 m = Height of the kite.
In the right ∆ OAB

sin 60° = \(\frac { AB }{ OB } \)
\(\frac{\sqrt{3}}{2}\) = \(\frac { 60 }{ OB } \)
\(\sqrt { 3 }\) × OB = 120
OB = \(\frac{120}{\sqrt{3}}=\frac{120 \times \sqrt{3}}{3}\)
Lenght of the string = 40 \(\sqrt { 3 }\) = 40 \(\sqrt { 3 }\) m

Question 19.
Prove that sin⁶ θ + cos⁶ θ + 3 sin² θ cos² θ = 1
Answer:
L. H. S = sin⁶ θ + cos⁶ θ + 3 sin² θ cos² θ
= (sin² θ)³ + (cos² θ)³ + 3 sin² θ cos² θ
= (sin² θ + cos² θ)³ – 3 × sin² θ cos² θ (sin² θ + cos² θ) + 3 × sin² θ cos² θ
[Using a³ + h³ = (a + h)³ – 3 ab (a + h)]
= 1³ – 3 sin² θ cos² θ (1) + 3 sin² θ cos² θ
= 1 – 3 sin² θ cos² θ + 3 sin² θ cos² θ
= 1
L.H. S = R. H. S

III. Answer The Following Questions.

Question 1.
Prove that \(\sqrt{\frac{\sec \theta-1}{\sec \theta+1}}+\sqrt{\frac{\sec \theta+1}{\sec \theta-1}}=2\) cosec θ
Answer:

Question 2.
Prove that \(\frac{1+\cos A}{\sin A}+\frac{\sin A}{1+\cos A}\) = 2 cosec A.
Answer:

Question 3.
Prove that 2 (sin⁶ θ + cos⁶ θ) – 3 (sin⁴ θ + cos⁴ θ) + 1 = θ
Answer:
consider, sin⁶ θ + cos⁶ θ
= (sin² θ)³ + (cos² θ)³
[Using a³ + b³ = (a + b)³ – 3 ab(a + b)]
= (sin² θ + cos² θ)³ – 3 sin² θ cos² θ (sin² θ + cos² θ)
= 1 – 3 sin² θ cos² θ
Now sin⁴ θ + cos⁴ θ = (sin² θ)² + (cos² θ)² (a² + b² = (a + b)² – 2 ab)
= (sin² θ + cos² θ)² – 2 (sin² θ cos² θ)
= 1 – 2 (sin² θ cos² θ)
L. H. S = 2 (sin⁶ θ + cos⁶ θ) – 3 (sin⁴ θ + cos⁴ θ) + 1
= 2(1 – 3 sin² θ cos² θ) – 3 (1 – 2 sin² θ cos² θ) + 1
= 2 – 6 sin² θ cos² θ – 3 + 6 sin² θ cos² θ + 1
= 3 – 3 = 0
L.H.S. = R.H.S

Question 4.
Prove that \(\frac{\sin \left(90^{\circ}-\theta\right)}{1+\sin \theta}+\frac{\cos \theta}{1-\cos \left(90^{\circ}-\theta\right)}\) = 2 sec θ
Answer:

Question 5.
Prove that \(\frac{\tan \theta}{1-\cot \theta}+\frac{\cot \theta}{1-\tan \theta}\) = 1 + sec θ cosec θ
Answer:

Question 6.
Prove that \(\frac{\sin \left(90^{\circ}-\theta\right)}{1-\tan \theta}+\frac{\cos \left(90^{\circ}-\theta\right)}{1-\cot \theta}\) = cos θ + sin θ
Answer:

L.H.S = R.H.S
Hence Proved

Question 7.
Prove that \(\frac{\tan \left(90^{\circ}-\theta\right)}{\csc \theta+1}+\frac{\csc \theta+1}{\cot \theta}\) = 2 sec θ
Answer:

Question 8.
Prove that

Answer:

Question 9.
Prove that (1 + cot θ – cosec θ) (1 + tan θ + sec θ) = 2
Answer:
L.H.S = (1 + cot θ – cosec θ) (1 + tan θ + sec θ)

L. H. S = R. H. S
Hence proved

Question 10.
Prove that \(\frac{\sin \theta-\cos \theta+1}{\sin \theta+\cos \theta-1}=\frac{1}{\sec \theta-\tan \theta}\)
Answer:

Question 11.
Prove that

Answer:

LHS = RHS
Hence proved

Question 12.
If tan θ = n tan α and sin θ = m sin α, then prove that cos² θ = \(\frac{m^{2}-1}{n^{2}-1}, n \neq \pm 1\)
Answer:
Given tan θ = n tan α and sin θ = m sin α
Let us eliminate using cosec² α – cot² α = 1

Question 13.
If sin θ, cos θ and tan θ are in G. P., then prove that cot⁶ θ – cot² θ = 1.
Answer:
Given, sin θ, cos θ, tan θ are in G. P., To prove cot⁶ θ – cot² θ = 1

Question 14.
A person in an helicopter flying at a height of 700 m, observes two objects lying opposite to each other on either bank of a river. The angles of depression of the objects are 30° and 45°. Find the width of the river. (\(\sqrt { 3 }\) = 1. 732)
Answer:
Let C be the point of observation.
The objects A and B lying opposite to each other on either bank of a river.
Width of the river AB = AD + BD
In the right ∆ ACD,

tan 30° = \(\frac { CD }{ AD } \) ⇒ \(\frac{1}{\sqrt{3}}\) = \(\frac { 700 }{ AD } \)
∴ AD = 700 \(\sqrt { 3 }\)
In the right ∆ BCD tan 45° = \(\frac { CD }{ BD } \)
1 = \(\frac { 700 }{ BD } \) ⇒ BD = 700 m
∴ Width of the river = AD + BD
= 700 \(\sqrt { 3 }\) + 700 = 700 (\(\sqrt { 3 }\) + 1)
= 700 (1.732 + 1) = 700 × 2.732 m
= 1912.400 m
∴ Width of the river = 1912.4 m

Question 15.
A person X standing on a horizontal plane, observes a bird flying at a distance of 100 m from him at an angle of elevation of 30°. Another person Y standing on the roof of a 20 m high building, observes the bird at the same time at an angle of elevation of 45°. If X and Y are on the opposite sides of the bird, then find the distance of the bird from Y.
Answer:
Let the position of the bird be “B”
Given, AY = 20 m, CD = 20 m, BX = 100 m, ∠BXD = 30° and ∠BYC = 45°
In the right ∆ BXD, sin 30° = \(\frac { BD }{ BX } \)
\(\frac { 1 }{ 2 } \) = \(\frac { BD }{ 100 } \) ⇒ BD = \(\frac{100 \times 1}{2}\) = 50 m

BC = BD – DC
BC = 50 m – 20 m = 30 m
In the right ∆ YBC, sin 45° = \(\frac { BC }{ BY } \)
\(\frac{1}{\sqrt{2}}\) = \(\frac { 30 }{ BY } \) ⇒ BY = 30\(\sqrt { 2 }\)
∴ Distance of the bird from the person Y is 30\(\sqrt { 2 }\) m

Question 16.
A boy is standing at some distance from a 30 m tall building and his eye level from the ground is 1.5 m. The angle of elevation from his eyes to the top of the building increases from 30° to 60° as he walks towards the building. Find the distance he walked towards the building.
Answer:
In the given figure A, B, C is a horizontal at the level of the boy
AD = A’D – AA’
AD = 30 – 1.5 = 28.5 m
Let the distance walked by the student CB is ‘x’ m.
Let AB be ‘y’ m
In the right ∆ ABD,tan 60° = \(\frac { AD }{ AB } \)
\(\sqrt { 3 }\) = \(\frac { 28.5}{ y } \)
y =\(\frac{28.5}{\sqrt{3}}\) …….(1)

In the right ∆ ACD,tan 30° = \(\frac { AD }{ AC } \)
\(\frac{1}{\sqrt{3}}\) = \(\frac{28.5}{x+y}\) ⇒ x + y = 28.5 \(\sqrt { 3 }\)
y = 28.5 \(\sqrt { 3 }\) – x ………..(2)
From (1) and (2) we get,
\(\frac{28.5}{\sqrt{3}}\) = 28.5 \(\sqrt { 3 }\) – x
28.5 = 28.5 × 3 – \(\sqrt { 3 }\) x
\(\sqrt { 3 }\) x = 28.5 × 3 – 28.5
\(\sqrt { 3 }\) x = 28.5 × (3 – 1) = 28.5 × 2
\(\sqrt { 3 }\) x = 57.0 m
x = \(\frac{57}{\sqrt{3}}=\frac{57 \times \sqrt{3}}{\sqrt{3} \times \sqrt{3}}\) ⇒ x = \(\frac{57 \times \sqrt{3}}{3}\) = 19 \(\sqrt { 3 }\) m.
∴ The distance walked by the boy = 19 \(\sqrt { 3 }\) m.

Question 17.
A straight highway leads to the foot of a tower. A man standing on the top of the tower spots a van at an angle of depression of 30°. The van is approaching the tower with a uniform speed. After 6 minutes, the angle of depression of the van is found to be 60°. How many more minutes will it take for the van to reach the tower?
Answer:
Let A be the point of observation. B and C be the positions of the van. Let the height of the tower AD be x. Let the speed of the van be “s”. C is the position of van after 6 minutes.
Time taken by the van from B to C be minutes.
Distance BC = 6 × s = 6 s (speed × time)
Let distance between CD be t s (time × speed)

In the right ∆ ABD, tan 30° = \(\frac { AD }{ DB } \)


∴ 3 more minutes will be taken by the van to reach the tower.

Students can download Maths Chapter 6 Trigonometry Unit Exercise 6 Questions and Answers, Notes, Samacheer Kalvi 10th Maths Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Maths Solutions Chapter 6 Trigonometry Unit Exercise 6

Question 1.
Prove that
(i) cot² A \(\left(\frac{\sec A-1}{1+\sin A}\right)\) + sec² A \(\left(\frac{\sin A-1}{1+\sec A}\right)\) = 0
(ii) \(\frac{\tan ^{2} \theta-1}{\tan ^{2} \theta+1}\) = 1 – 2 cos² θ
Answer:


Hence it is proved

= 1 – cos² θ
L.H.S = R.H.S
Hence it is proved.

Question 2.
Prove that
\(\left(\frac{1+\sin \theta-\cos \theta}{1+\sin \theta+\cos \theta}\right)^{2}=\left(\frac{1-\cos \theta}{1+\cos \theta}\right)\)
Answer:

LHS = RHS
Hence it is proved

Question 3.
If x sin² θ + y cos² θ = sin θ cos θ and x sin θ = y cos θ, then prove that x² + y² = 1.
Answer:
Given x sin² θ + y cos² θ = sin θ cos θ
x sin θ = y cos θ ……..(1)
x sin³ θ + y cos³ θ = sin θ cos θ
x sin θ (sin² θ) + y cos θ (cos² θ) = sin θ cos θ
x sin θ (sin² θ) + x sin θ (cos² θ) = sin θ cos θ
x sin θ (sin² θ + cos² θ) = sin θ cos θ
x sin θ = sin θ cos θ
x = cos θ
substitute x = cos θ in (1)
cos θ sin θ = y cos θ y = sin θ
L. H. S = x² + y² = cos² θ + sin² θ = 1
L.H. S = R.H.S
Hence it is proved.

Question 4.
If a cos θ – b sin θ = c, then prove that (a sin θ + b cos θ) = ± \(\sqrt{a^{2}+b^{2}-c^{2}}\).
Answer:
Given a cos θ – b sin θ = c
Squaring on both sides
(a cos θ – b sin θ)² = c²
a² cos² θ + b² sin² θ – 2 ab cos θ sin θ = c²
a² (1 – sin² θ) + b² (1 – cos² θ) – 2 ab cos θ sin θ = c²
a² – a² sin² θ + b² – b² cos² θ – 2 ab cos θ sin θ = c²
– a² sin² θ – B² – cos² θ – 2 ab cos θ sin θ = – a² – b² + c²
a² sin² θ + b² cos² θ + 2 ab cos θ sin θ = a² + b² – c²
(a sin θ + b cos θ)² – a² + b² – c²
a sin θ + b cos θ = ± \(\sqrt{a^{2}+b^{2}-c^{2}}\)
Hence it is proved.

Question 5.
A bird is sitting on the top of a 80 m high tree. From a point on the ground, the angle of elevation of the bird is 45° . The bird flies away horizontally in such away that it remained at a constant height from the ground. After 2 seconds, the angle of elevation of the bird from the same point is 30° . Determine the speed at which the bird flies. (\(\sqrt { 3 }\) = 1.732)
Answer:

A is the initial position of the bird B is the final position of the bird Let the speed of the bird be “s”
Distance = speed × time
∴ AB = 2x
Let CD be x
∴ CE = x + 2s
In the ∆ CDA, tan 45° = \(\frac { AD }{ CD } \)
1 = \(\frac { 80 }{ x } \)
x = 80 ……..(1)
In the ∆ BCE
tan 30° = \(\frac { BE }{ CE } \)
\(\frac{1}{\sqrt{3}}\) = \(\frac { 80 }{ x+2s } \)
x + 2s = 80 \(\sqrt { 3 }\)
x = 80 \(\sqrt { 3 }\) – 2 s ………(2)
From (1) and (2) we get
80 \(\sqrt { 3 }\) – 2 s = 80
80 \(\sqrt { 3 }\) – 80 = 2 s ⇒ 80 (\(\sqrt { 3 }\) – 1) = 2 s
s = \(\frac{80(\sqrt{3}-1)}{2}\) = 40 (1.732 – 1) = 40 × 0.732 = 29.28
Speed of the flying bird = 29.28 m/sec

Question 6.
An aeroplane is flying parallel to the Earth’s surface at a speed of 175 m/sec and at a height of 600 m. The angle of elevation of the aeroplane from a point on the Earth’s surface is 37° at a given point. After what period of time does the angle of elevation increase to 53°? (tan 53° = 1.3270, tan 37° = 0.7536)
Answer:
Let C is the initial and D is the final position of the aeroplane.
Let the time taken by the aeroplane be “t”
∴ CD = 175 t (Distance = speed × time)

Let AB be x
∴ AE = x + 175 t
In the right ∆ ABC


∴ Time taken is 1. 97 seconds

Question 7.
A bird is flying from A towards B at an angle of 35°, a point 30 km away from A. At B it changes its course of flight and heads towards C on a bearing of 48° and distance 32 km away.
(i) How far is B to the North of A?
(ii) How far is B to the West of A?
(iii) How far is C to the North of B?
(iv) How far is C to the East of B?
(sin 55° = 0.8192, cos 55° = 0.5736, sin 42° = 0.6691, cos 42° = 0.7431)
Answer:

(i) To find the distance of B to the north of A
In ∆ ABB,

Distance of B to the North of A = 24. 58 km

(ii) Distance from B to the west of A is AB’
In ∆ ABB’
cos 55° = \(\frac{\mathrm{AB}^{\prime}}{\mathrm{AB}}\)
0.5736 = \(\frac{A B^{\prime}}{30}\)
∴ AB’ = 0.5736 × 30 = 17. 21 km
Distance of B to the West of A is 17. 21 km

(iii) Distance from C to the North of B is CD
In the right ∆ BCD, sin 42° = \(\frac { CD }{ BC } \)
0.6691 = \(\frac { BD }{ 32 } \)
∴ CD = 0.6691 × 32 = 21.41 km
Distance of C to the North B is 21. 41 km

(iv) The distance of C to the East of B is BD
In the right ∆ BDC, cos 42° = \(\frac { BD }{ BC } \)
0.7431 = \(\frac { BD }{ 32 } \)
∴ BD = 0.7431 × 32
= 23.78 km
Distance of C to the East of B is 23.78 km.

Question 8.
Two ships are sailing in the sea on either side of the lighthouse. The angles of depression of two ships as observed from the top of the lighthouse are 60° and 45° respectively. If the distance between the ships is 200 \(\left(\frac{\sqrt{3}+1}{\sqrt{3}}\right)\) meters, find the height of the lighthouse
Answer:
Let A and B the position of the first ship and the second ship
Distance = 200 \(\left(\frac{\sqrt{3}+1}{\sqrt{3}}\right)\) m
Let the height of the light house CD be “h”

In the right ∆ ACD, tan 60° = \(\frac { CD }{ AD } \)
\(\sqrt { 3 }\) = \(\frac { h }{ AD } \)
∴ AD = \(\frac{h}{\sqrt{3}}\) ……….(1)
In the right ∆ BCD
tan 45° = \(\frac { DC }{ BD } \)
1 = \(\frac { h }{ BD } \)
∴ BD = h
Distance between the two ships = AD + BD
200 (\(\frac{\sqrt{3}+1}{\sqrt{3}}\)) = \(\frac{h}{\sqrt{3}}\) + h ⇒ 200 (\(\sqrt { 3 }\) + 1) = h + \(\sqrt { 3 }\) h
200 (\(\sqrt { 3 }\) + 1) = h(1 + \(\sqrt { 3 }\)) ⇒ h = \(\frac{200(\sqrt{3}+1)}{(1+\sqrt{3})}\)
h = 200
Height of the light house = 200 m

Question 9.
A building and a statue are in opposite side of a street from each other 35 m apart. From a point on the roof of building the angle of elevation of the top of statue is 24° and the angle of depression of base of the statue is 34° . Find the height of the statue. (tan 24° = 0.4452, tan 34° = 0.6745)
Answer:
Let the height of the statue be “h” m
Let AD be x
∴ EC = h – x
In the right ∆ ABD,

tan 34° = \(\frac { AD }{ AB } \)
0.6745 = \(\frac { x }{ 35 } \)
∴ x = 0.6745 × 35 ⇒ x = 23.61 m
In the right ∆ DEC ⇒ tan 24° = \(\frac { EC }{ DE } \)
0.4452 = \(\frac { h-x }{ 35 } \) ⇒ h – x = 0.4452 × 35
h – 23.61 = 15. 58 ⇒ h = 15.58 + 23.61 = 39.19 m
Height of the statue = 39.19 m

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Maths Guide Pdf Chapter 1 Applications of Matrices and Determinants Ex 1.7 Textbook Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Maths Solutions Chapter 1 Applications of Matrices and Determinants Ex 1.7

Question 1.
Solve the following system of homogeneous equations.
(i) 3x + 2y + 7z = 0; 4x – 3y – 2z = 0; 5x + 9y + 23z = 0
Solution:

ρ(A) = 2 ρ[A | B] = 2
ρ(A) ρ[A | B] = 2 < n
The system is consistent. It has non trivial solution.
Writing the equivalent equations from echelon form
3x + 2y + 7z = 0 ………… (1)
-17y – 34z = 0 ……….. (2)
Put z = t
(2) ⇒ -17y = 34t
y = \(\frac {34t}{-17}\) = -2t
(1) ⇒ 3x + 2(-2t) + 7t = 0
3x – 4t + 7t = 0
3x + 3t = 0
3x = -3t
x = -t
(x, y, z) (-t, -2t, t) ∀ t ∈ R

(ii) 2x + 3y – z = 0, x – y – 2z = 0, 3x + y + 3z = 0
Solution:

ρ(A) = 3 ρ[A | B] = 3
ρ(A) = ρ[A | B] = 3
The system is consistent. It has trivial solution.
x = 0, y = 0, z = 0

Question 2.
Determine the values of λ for which the following system of equations.
x + y + 3z = 0; 4x + 3y + λz = 0, 2x + y + 2z = 0 has
(i) a unique solution
(ii) a non-trivial solution.
Solution:

Case (i):
if λ ≠ 8
ρ(A) = 3 ρ(A | B) = 3
ρ(A) = ρ(A | B) = 3 = n
The system is consistent. It has unique (trivial) solution.
∴ Solution x = 0, y = 0, z = 0

Case (ii):
if λ = 8
ρ(A)= ρ(A | B) = 2
ρ(A) = ρ(A | B) = 2 < n
The system is consistent. It has non trivial solution.

Question 3.
By using Gaussian elimination method, balance the chemical -reaction equation:
C₂H₆ + O₂ → H₂O + CO₂.
Solution:
We are searching for positive integers x₁, x₂, x₃ and x₄
x₁ C₂H₆ + x₂ O₂ → x₃ H₂O + x₄ CO₂ ……….(1)
The number of carbon atoms on the LHS of (1) should be equal to the number of carbon atoms on the RHS of (1) so we get a linear
homogeneous equation.
2x₁ x₄ = 2x₁ – x₄ = 0 ……..(2)
6x₁ = 2x₃ = 6x₁ – 2x₃ = 0
÷ 2 ⇒ 3x₁ – x₃ = 0 ………(3)
2x₂ = x₃ + 2x₄ ⇒ 2x₂ – x₃ – 2x₄ = 0 ……… (4)
Equation (2), (3) and (4) constitute a homogeneous system of linear equations in four unknowns.
Augmented matrix

The system is consistent and has an infinite number of solutions.
Writing the equations using the echelon form we get
-2x₃ + 3x₄ = 0 ……….. (1)
2x₂ – x₃ – 2x₄ = 0 ………… (2)
2x₁ – x₄ = 0 …………. (3)
Put x₄ = t
(3) ⇒ 2x₁ – t = 0
x₁ = \(\frac {t}{2}\)
(1) ⇒ -2x₃ + 3x₄ = 0
-2x₃ = -3t
x₃ = \(\frac {3}{2}\) t
(2) ⇒ 2x₂ – x₃ – 2x₄ = 0
2x₂ – \(\frac {3}{2}\) t – 2t = 0
2x₂ = \(\frac {3}{2}\) t + 2t = \(\frac {7t}{2}\)
x₂ = \(\frac {7t}{4}\)
(x₁, x₂, x₃, x₄) = (\(\frac {t}{2}\), \(\frac {7t}{4}\), \(\frac {3}{2}\)t, t) ∀ t ∈ R
since x₁, x₂, x₃ and x₄ are positive integers.
Let us choose t = 4

So the balanced equation is
2C₂H₆ + 7O₂ → 6H₂O + 4CO₂.

Students can download 10th Science Chapter 1 Laws of Motion Questions and Answers, Notes, Samacheer Kalvi 10th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 1 Laws of Motion

Samacheer Kalvi 10th Science Laws of Motion Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
Inertia of a body depends on:
(a) weight of the object
(b) acceleration due to gravity of the planet
(c) mass of the object
(d) both (a) & (b)
Answer:
(c) mass of the object

Question 2.
Impulse is equals to ______ .
(a) rate of change of momentum
(b) rate of force and time
(c) change of momentum
(d) rate of change of mass.
Answer:
(c) change of momentum

Question 3.
Newton’s III law is applicable:
(a) for a body is at rest
(b) for a body in motion
(c) both (a) & (b)
(d) only for bodies with equal masses
Answer:
(b) for a body in motion

Question 4.
Plotting a graph for momentum on the X-axis and time on Y-axis. Slope of momentum – time graph gives _____
(a) Impulsive force
(b) Acceleration
(c) Force
(d) Rate of force.
Answer:
(c) Force

Question 5.
In which of the following sport the turning effect of force is used?
(a) swimming
(b) tennis
(c) cycling
(d) hockey
Answer:
(c) cycling

Question 6.
The unit of ‘g’ is ms^-2. It can be also expressed as:
(a) cm s^-2
(b) N kg^-1
(c) N m²kg^-1
(d) cm²s^-2
Answer:
(a) cm s^-2

Question 7.
One kilogram force equals to _____ .
(a) 9.8 dyne
(b) 9.8 × 10⁴ N
(c) 98 × 10⁴ dyne
(d) 980 dyne.
Answer:
(c) 98 × 10⁴ dyne

Question 8.
The mass of a body is measured on planet Earth as M kg. When it is taken to a planet of radius half that of the Earth then its value will be ….. kg.
(a) 4 M
(b) 2 M
(c) M/4
(d) M
Answer:
(c) M/4

Question 9.
If the Earth shrinks to 50% of its real radius its mass remaining the same, the weight of a body on the Earth will:
(a) decrease by 50%
(b) increase by 50%
(c) decrease by 25%
(d) increase by 300%
Answer:
(c) decrease by 25%

Question 10.
To project the rockets which of the following principle(s) is / (are) required?
(a) Newton’s third law of motion
(b) Newton’s law of gravitation
(c) law of conservation of linear momentum
(d) both a and c.
Answer:
(d) both a and c.

II. Fill in the blanks

1. To produce a displacement …….. is required.
2. Passengers lean forward when the sudden brake is applied in a moving vehicle. This can be explained by ……….
3. By convention, the clockwise moments are taken as ……… and the anticlockwise moments are taken as ……….
4. …….. is used to change the speed of the car.
5.  A man of mass 100 kg has a weight of …….. at the surface of the Earth.

Answer:

1. force
2. inertia
3. negative, positive
4. Accelerator
5. Weight = m × g = 100 × 9.8 = 980 N

III. State whether the following statements are true or false. Correct the statement if it is false.

1. The linear momentum of a system of particles is always conserved.
2. Apparent weight of a person is always equal to his actual weight.
3. Weight of a body is greater at the equator and less at the polar region.
4. Turning a nut with a spanner having a short handle is so easy than one with a long handle.
5. There is no gravity in the orbiting space station around the Earth. So the astronauts feel weightlessness.

Answer:

1. True
2. False – Apparent weight of a person is not always equal to his actual weight.
3. False – Weight of a body is minimum at the equator. It is maximum at the poles.
4. False – Turning a nut with a spanner having a longer handle is so easy than one with a short handle.
5. False – Astronauts are falling freely around the earth due to their huge orbital velocity.

IV. Match the following.

Answer:
A. (ii)
B. (Hi)
C. (iv)
D. (i)

V. Assertion and Reasoning.

Mark the correct choice as:
(a) If both the assertion and the reason are true and the reason is the correct explanation of assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
(c) Assertion is true, but the reason is false.
(d) Assertion is false, but the reason is true.
1. Assertion: The sum of the clockwise moments is equal to the sum of the anticlockwise moments.
Reason: The principle of conservation of momentum is valid if the external force on the system is zero.
2. Assertion: The value of ‘g’ decreases as height and depth increases from the surface of the Earth.
Reason: ‘g’ depends on the mass of the object and the Earth.
Answer:
1. (b)
2. (c)

VI. Answer Briefly.

Question 1.
Define inertia. Give its classification.
Answer:
The inherent property of a body to resist any change in its state of rest or the state of uniform motion, unless it is influenced upon by an external unbalanced force, is known as ‘inertia’.
Classifications:

1. Inertia of rest
2. Inertia of motion
3. Inertia of direction

Question 2.
Classify the types of force based on their application.
Answer:
Based on the direction in which the forces act, they can be classified into two types as:

1. Like parallel forces: Two or more forces of equal or unequal magnitude acting along the same direction, parallel to each other are called like parallel forces.
2. Unlike parallel forces: If two or more equal forces or unequal forces act along with opposite directions parallel to each other, then they are called, unlike parallel forces.

Question 3.
If a 5 N and a 15 N forces are acting opposite to one another. Find the resultant force and the direction of action of the resultant force.
Answer:
F₁ = 5 N
F₂ = 15 N
∴ Resultant force F_R = F₁ – F₂
= 5 – 15 = -10 N
It acts in the direction of the force of 15 N (F₂).

Question 4.
Differentiate mass and weight.
Answer:
Ratio of masses of planets is
m₁ = m₂ = 2 : 3
Ratio of radii
R₁ = R₂ = 4 : 7
We know

Question 5.
Define the moment of a couple.
Answer:
When two equal and unlike parallel forces applied simultaneously at two distinct points constitute a couple. A couple results in causes the rotation of the body. This rotating effect of a couple is known as the moment of a couple.

Question 6.
State the principle of moments.
Answer:
Principle of moments states that if a rigid body is in equilibrium on the action of a number of like (or) unlike parallel forces then the algebraic sum of the moments in the clockwise direction is equal to the algebraic sum of the moments in the anticlockwise direction.

Question 7.
State Newton’s second law.
Answer:
The force acting on a body is directly proportional to the rate of change of linear momentum of the body and the change in momentum takes place in the direction of the force.

Question 8.
Why a spanner with a long handle is preferred to tighten screws in heavy vehicles?
Answer:
When a spanner is having a long handle, the turning effect of the applied force is more when the distance between the fixed edge and the point of application of force is more. Hence a spanner with a long handle is preferred to tighten screws in heavy vehicles.

Question 9.
While catching a cricket ball the fielder lowers his hands backwards. Why?
Answer:
While catching a cricket ball the fielder lowers his hands backwards, so increase the time during which the velocity of the cricket ball decreases to zero. Therefore the impact of force on the palm of the fielder will be reduced.

Question 10.
How does an astronaut float in a space shuttle?
Answer:
Astronauts are not floating but falling freely around the earth due to their huge orbital velocity. Since spaceshuttle and astronauts have equal acceleration, they are under free fall condition. (R = 0) Hence, both the astronauts and the space station are in the state of weightlessness.

VII. Solve the given problems.

Question 1.
Two bodies have a mass ratio of 3 : 4 The force applied on the bigger mass produces an acceleration of 12 ms². What could be the acceleration of the other body, if the same force acts on it.
Answer:
Ratio of masses m₁ : m₂ = 3 : 4
Acceleration of m₂ is a₂ = 12 m/s²
Force acting of m₂ is F₂ = m₂a₂
F₂ = 4 × 12 = 48N
but F₂ = F₁
∴ Force acting on m₁ is F₁ = 48N
∴ Acceleration of m₁ = a₁ = \(\frac{F_1}{m_1}\)
a₁ = \(\frac{48}{3}\)
= 16 m/s²
Acceleration of the other body ax = 16 m/s²

Question 2.
A ball of mass 1 kg moving with a speed of 10 ms-1 rebounds after a perfect elastic collision with the floor. Calculate the change in linear momentum of the ball.
Answer:
Given mass = 1 kg, speed = 10 ms^-1
Initial momentum = mu = 1 × 10 = 10 kg ms^-1
Final momentum = -mu = -10 kg ms^-1
Change in momentum = final momentum – initial momentum = -mu – mu
Change in momentum = -20 kg ms^-1

Question 3.
A mechanic unscrew a nut by applying a force of 140 N with a spanner of length 40 cm. What should be the length of the spanner if a force of
40 N is applied to unscrew the same nut?
Answer:
Force acting on the screw F₁ = 140 N
Length of a spanner d₁ = 40 × 10^-2 m
Second force applied to the screw F₂ = 40 N
Let the length of spanner be d₂
According to the Principle of moments,
F₁ × d₁ = F₂ × d₂
= 140 × 40 = 40 × d₂
∴ d₂ = \(\frac{140×40}{40}\)
= 140 × 10^-2 m
Length of a spanner = 140 × 10^-2 m

Question 4.
The ratio of masses of two planets is 2 : 3 and the ratio of their radii is 4 : 7. Find the ratio of their accelerations due to gravity.
Answer:
Ratio of masses of two planets is
m₁ : m₂ = 2 : 3
Ratio of their radii,
R₁ : R₂ = 4 : 7
We know g
Img 2
∴ g₁ : g₂ = 49 : 24

VIII. Answer in Detail.

Question 1.
What are the types of inertia? Give an example for each type.
Answer:
Types of Inertia:
(i) Inertia of rest: The resistance of a body to change its state of rest is called inertia of rest.
E.g.: When you vigorously shake the branches of a tree, some of the leaves and fruits are detached and they fall down (Inertia of rest).

(ii) The inertia of motion: The resistance of a body to change its state of motion is called inertia of motion.
E.g.: An athlete runs some distance before jumping. Because this will help him jump longer and higher. (Inertia of motion)

(iii) Inertia of direction: The resistance of a body to change its direction of motion is called inertia of direction.
E.g.: When you make a sharp turn while driving a car, you tend to lean sideways, (Inertia of direction).

Question 2.
State Newton’s laws of motion.
Answer:
(i) Newton’s First Law : States that “every body continues to be in its state of rest or the state of uniform motion along a straight line unless it is acted upon by some external force”.

(ii) Newton’s Second Law : States that “the force acting on a body is directly proportional to the rate of change of linear momentum of the body and the change in momentum takes place in the direction of the force”.

(iii) Newton’s third law : States that “for every action, there is an equal and opposite reaction. They always act on two different bodies”.

Question 3.
Deduce the equation of a force using Newton’s second law of motion.
Answer:
Let, ‘m’ be the mass of a moving body, moving along a straight line with an initial speed V. After a time interval of ‘t’, the velocity of the body changes to v due to the impact of an unbalanced external force F.
Initial momentum of the body P_i = mu
Final momentum of the body P_f = mv
Change in momentum Δp = P_i – P_f – mv – mu
By Newton’s second law of motion,
Force, F ∝ rate of change of momentum
F ∝ change in momentum / time
F ∝ \(\frac{mv-mu}{t}\)
F = \(\frac {km(v-u)}{t}\)
Here, k is the proportionality constant.
k = 1 in all systems of units. Hence,
F = \(\frac {m(v-u)}{t}\)
Since,
acceleration = change in velocity/time,
a = (v – u)/t.
Hence, we have F = m × a
Force = mass × acceleration

Question 4.
State and prove the law of conservation of linear momentum.
Answer:

Proof:
Let two bodies A and B having masses m₁ and m₂ move with initial velocity u₁ and u₂ in a straight line. Let the velocity of the first body be higher than that of the second body, i.e,, u₁ > u₂. During an interval of time t second, they tend to have a collision. After the impact, both of them move along the same straight line with a velocity v₁ and v₂ respectively.
Force on body B due to A,
F_B = m₂(v₂ – u₂)/t
Force on body A due to B,
F_A = m₁(v₁ – u₁)/t
By Newton’s III law of motion,
Action force = Reaction force
F_A = -F_B
m₁(v₁ – u₁)/t = -m₂ (v₂ – u₂)/t
m₁ v₁ + m₂ v₂ = m₁ u₁ + m₂ u₂
The above equation confirms in the absence of an external force, the algebraic sum of the momentum after collision is numerically equal to the algebraic sum of the momentum before collision.
Hence the law of conservation of linear momentum is proved.

Question 5.
Describe rocket propulsion.
Answer:

1. Propulsion of rockets is based on the law of conservation of linear momentum as well as Newton’s III law of motion.
2. Rockets are filled with fuel (either liquid or solid) in the propellant tank. When the rocket is fired, this fuel is burnt and hot gas is ejected with high speed from the nozzle of the rocket, producing a huge momentum.
3. To balance this momentum, an equal and opposite reaction force is produced in the combustion chamber, which makes the rocket project forward.
4. While in motion, the mass of the rocket gradually decreases, until the fuel is completely burnt out.
5. Since there is no net external force acting on it, the linear momentum of the system is conserved.
6. The mass of the rocket decreases with altitude, which results in the gradual increase in the velocity of the rocket.
7. At one stage, it reaches a velocity, which is sufficient to just escape from the gravitational pull of the Earth. This velocity is called escape velocity.

Question 6.
State the universal law of gravitation and derive its mathematical expression.
Answer:
Newton’s universal law of gravitation states that every particle of matter in this universe attracts every other particle with a force. This force is directly proportional to the product of their masses and inversely proportional to the square of the distance between the centres of these masses. The direction of the force acts along the line joining the masses.

Force between the masses is always attractive and it does not depend on the medium where they are placed.

Let, m₁ and m₂ be the masses of two bodies A and B placed r metre apart in space
Force
F ∝ m₁ × m₂
F ∝ 1/r²
On combining the above two expressions
F ∝ \(\frac{m_1×m_2}{r^2}\)
F = \(\frac{Gm_1 m_2}{r^2}\)
Where G is the universal gravitational constant. Its value in SI unit is 6.674 × 10^-11 N m² kg^-2.

Question 7.
Give the applications of gravitation.
Answer:

1. Dimensions of the heavenly bodies can be measured using the gravitation law. Mass of the Earth, the radius of the Earth, acceleration due to gravity, etc. can be calculated with higher accuracy.
2. Helps in discovering new stars and planets.
3. One of the irregularities in the motion of stars is called ‘Wobble’ lead to the disturbance in the motion of a planet nearby. In this condition, the mass of the star can be calculated using the law of gravitation.
4. Helps to explain germination of roots is due to the property of geotropism, which is the property of a root responding to the gravity.
5. Helps to predict the path of the astronomical bodies.

IX. HOT questions.

Question 1.
Two blocks of masses 8 kg and 2 kg respectively lie on a smooth horizontal surface in contact with one other. They are pushed by a horizontally applied force of 15 N. Calculate the force exerted on the 2 kg mass.
Answer:
Mass of first block m₁ = 8 kg
Mass of second block m₂ = 2 kg
Total mass M = 8 + 2 = 10 kg
Force applied F = 15 N
∴ Acceleration a = \(\frac{F}{M}\)
\(\frac{15}{10}\) = 1.5 m/s²
Force exerted on the 2 kg mass,
F = ma
= 2 × 1.5 = 3 N

Question 2.
A heavy truck and bike are moving with the same kinetic energy. If the .mass of the truck is four times that of the bike, then calculate the ratio of their momenta. (Ratio of momenta = 1 : 2)
Answer:
Let the mass of truck be m₁
Let the mass of bike be m₂
m₁ = 4m₂
∴ \(\frac{m_1}{m_2}\) = 4
Kinetic energy K.E₁ = K.E₂
∴ m₂, \({ v }_{ 1 }^{ 2 }\) = m₂\({ v }_{ 1 }^{ 2 }\)

Ratio of momenta be P₁ : P₂

∴ Ratio of their momenta = 2 : 1

Question 3.
“Wearing helmet and fastening the seat belt is highly recommended for safe journey” Justify your answer using Newton’s laws of motion.
Answer:
(i) According to Newton’s Second Law, when you fall from a bike on the ground with a force equal to your mass and acceleration of the bike.
According to Newton’s Third Law, an equal and opposite reacting force on the ground is exerted on your body. When you do not wear a helmet, this reacting force can cause fatal head injuries. So it is important to wear helmet for a safe journey.

(ii) Inertia in the reason that people in cars need to wear seat belts. A moving car has inertia, and so do the riders inside it. When the driver applies the brakes, an unbalanced force in applied to the car. Normally the bottom of the seat applies imbalanced force friction which slows the riders down as the car slows. If the driver stops the car suddenly, however, this force is not exerted over enough time to stop the motion of the riders. Instead, the riders continue moving forward with most of their original speed because of their inertia.

Samacheer Kalvi 10th Science Laws of Motion Additional Important Questions and Answers

I. Choose the correct answer.

Question 1.
When a force is exerted on an object, it can change its:
(a) state
(b) shape
(c) position
(d) all the above
Answer:
(d) all the above

Question 2.
When the train stops, the passenger moves forward, It is due to ______ .
(a) Inertia of passenger
(b) Inertia of train
(c) gravitational pull by the earth
(d) None of the above.
Answer:
(a) Inertia of passenger

Question 3.
Force is a …….. quantity.
(a) vector
(b) fundamental
(c) scalar
(d) none
Answer:
(a) vector

Question 4.
The force of gravitation is ________ .
(a) repulsive
(b) conservative
(c) electrostatic
(d) non – conservative.
Answer:
(b) conservative

Question 5.
The laws of motion of a body is given by:
(a) Galileo
(b) Archimedis
(c) Einstein
(d) Newton
Answer:
(d) Newton

Question 6.
A bodyweight 700 N on earth. What will be its weight on a planet having 1 / 7 of earth’s mass and half of the earth’s radius?
(a) 400 N
(b) 300 N
(c) 200 N
(d) 100 N.
Answer:
(a) 400 N

Question 7.
From the following statements write down that which is not applicable to mass of an object:
(a) It is a fundamental quantity
(b) It is measured using physical balance
(c) It is measured using spring balance
(d) It is the amount of matter.
Answer:
(c) It is measured using spring balance

Question 8.
Newton’s first law of motion defines:
(a) inertia
(b) force
(c) acceleration
(d) both inertia and force
Answer:
(d) both inertia and force

Question 9.
Mechanics is divided into ____ types.
(a) one
(b) two
(c) three
(d) four.
Answer:
(b) two

Question 10.
When an object undergoes acceleration:
(a) its velocity increases
(b) its speed increases
(c) its motion is uniform
(d) a force always acts on it
Answer:
(d) a force always acts on it

Question 11.
On what factor does inertia of a body depend?
(a) volume
(b) area
(c) mass
(d) density
Answer:
(c) mass

Question 12.
_____ deals with the motion of bodies without considering the cause of motion.
(a) Inertia
(b) Force
(c) Kinematics
(d) kinetics.
Answer:
(c) Kinematics

Question 13.
If mass of an object is m, velocity v, acceleration a and applied force is F and momentum P is given by:
(a) P = m × v
(b) P = m × a
(c) P = \(\frac{m}{v}\)
(d) P = \(\frac{v}{m}\)
Answer:
(a) P = m × v

Question 14.
Which of the following is a vector quantity?
(a) speed
(b) distance
(c) momentum
(d) time
Answer:
(c) momentum

Question 15.
Unit of momentum in SI system is ______ .
(a) ms^-1
(b) Kg ms^-2
(c) Kg ms^-1
(d) ms^-2
Answer:
(c) Kg ms^-1

Question 16.
Force is measured based on:
(a) Newton’s first law
(b) Newton’s second law
(c) Newton’s third law
(d) All the above
Answer:
(b) Newton’s second law

Question 17.
Force measures rate of change of:
(a) acceleration
(b) velocity
(c) momentum
(d) distances
Answer:
(c) momentum

Question 18.

The rotating or turning effect of a force about a fixed point or fixed axis is called _____ .
(a) Force
(b) momentum
(c) torque
(d) couples.
Answer:
(c) torque

Question 19.
The physical quantity which is equal to the rate of change of momentum is:
(a) displacement
(b) acceleration
(c) force
(d) impulse
Answer:
(c) force

Question 20.
The momentum of a massive object at rest is:
(a) very large
(b) very small
(c) zero
(d) infinity
Answer:
(c) zero

Question 21.
The velocity which is sufficient to just escape from the gravitational pull of the earth is _____ .
(a) drift velocity
(b) escape velocity
(c) gradual velocity
(d) final velocity.
Answer:
(b) escape velocity

Question 22.
A force applied on an object is equal to:
(a) product of mass and velocity
(b) sum of mass and velocity of an object
(c) product of mass and acceleration
(d) sum of mass and acceleration
Answer:
(c) product of mass and acceleration

Question 23.
Action and reaction do not balance each other because they:
(a) act on the same body
(b) do not act on the same body
(c) are in opposite direction
(d) are unequal
Answer:
(b) do not act on the same body

Question 24.
The value of variation of accelaration due to gravity (g) is ______ at the centre of the earth.
(a) one
(b) zero
(c) ∞
(d) \(\frac{1}{\infty}\).
Answer:
(b) zero

Question 25.
Action and reaction forces are:
(a) equal in magnitude
(b) equal in direction
(c) opposite in direction
(d) both equal in magnitude and opposite in direction
Answer:
(d) both equal in magnitude and opposite in direction

Question 26.
If mass of a body is doubled then its acceleration becomes:
(a) halved
(b) doubled
(c) thrice
(d) zero
Answer:
(a) halved

Question 27.
The principle involved in the working of a jet plane is:
(a) Newton’s first law
(b) Conservation of momentum
(c) Law of inertia
(d) Newton’s second law
Answer:
(b) Conservation of momentum

Question 28.
_____ of a body is defined as the quantity of matter contained in the object.
(a) weight
(b) mass
(c) force
(d) momentum.
Answer:
(b) mass

Question 29.
A gun gets kicked back when a bullet is fired. It is a good example of Newton’s:
(a) gravitational law
(b) first law
(c) second law
(d) third law
Answer:
(d) third law

Question 30.
To change the state or position of an object force is essential.
(a) balanced
(b) unbalanced
(c) electric
(d) elastic
Answer:
(b) unbalanced

Question 31.
When a bus starts suddenly the passengers in the standing position are pushed backwards, this action is due to:
(a) first law of motion
(b) second law of motion
(c) third law of motion
(d) conservation of momentum
Answer:
(a) first law of motion

Question 32.
When a body at rest breaks into two pieces of equal masses, then the parts will move:
(a) in same direction
(b) along different directions
(c) in opposite directions with unequal speeds
(d) in opposite directions with equal speeds
Answer:
(d) in opposite directions with equal speeds

Question 33.
The principle of function of a jet aeroplane is based on:
(a) first law of motion
(b) second law of motion
(c) third law of motion
(d) all the above
Answer:
(c) third law of motion

Question 34.
Which of the following has the largest inertia?
(a) pin
(b) book
(c) pen
(d) table
Answer:
(d) table

Question 35.
An athlete runs a long path before taking a long jump to increase:
(a) energy
(b) inertia
(c) momentum
(d) force
Answer:
(c) momentum

Question 36.
The weight of a person is 50 kg. The weight of that person on the surface
(a) 50 N
(b) 35 N
(c) 380 N
(d) 490 N
Answer:
(d) 490 N

Question 37.
Which is incorrect statement about the action and reaction referred to Newton’s third law of motion?
(a) They are equal
(b) They are opposite
(c) They act on the same object
(d) They act on two different objects
Answer:
(c) They act on the same object

Question 38.
The tendency of a force to rotate a body about a given axis is called:
(a) turning effect of a force
(b) moment of force
(c) torque
(d) all the above
Answer:
(d) all the above

Question 39.
The magnitude of the moment of force is:
(a) product of force and the perpendicular distance
(b) product of force and velocity
(c) ratio of force to the acceleration
(d) ratio of force to the perpendicular distance
Answer:
(a) product of force and the perpendicular distance

Question 40.
If the force rotates the body in the anticlockwise direction, then the moment is called:
(a) clockwise moment
(b) anticlockwise moment
(c) couple
(d) torque
Answer:
(b) anticlockwise moment

Question 41.
Anticlockwise moment is:
(a) positive
(b) negative
(c) opposite
(d) zero
Answer:
(a) positive

Question 42.
Clockwise moment or torque is:
(a) zero
(b) always one
(c) negative
(d) positive
Answer:
(c) negative

Question 43.
SI unit of moment of force is:
(a) Nm^-2
(b) Nm^-1
(c) Ns
(d) Nm
Answer:
(d) Nm

Question 44.
Moment of force produces:
(a) acceleration
(b) linear motion
(c) velocity
(d) angular acceleration
Answer:
(d) angular acceleration

Question 45.
Two equal and opposite forces whose lines of action do not coincide are said to constitute a:
(a) couple
(b) torque
(c) unlike force
(d) parallel force
Answer:
(a) couple

Question 46.
Couple produces:
(a) translatory motion
(b) rotatory motion
(c) translatory as well as rotatory motion
(d) neither translatory nor rotatory
Answer:
(b) rotatory motion

Question 47
……. is an example of couple.
(a) opening or closing a tap
(b) turning of a key in a lock
(c) steering wheel of car
(d) all the above
Answer:
(d) all the above

Question 48.
Force of attraction between any two objects in the universe is called:
(a) gravitational force
(b) mechanical force
(c) magnetic force
(d) electrostatic force
Answer:
(a) gravitational force

Question 49.
Universal law of gravitation was given by:
(a) Archimedes
(b) Aryabhatta
(c) Kepler
(d) Newton
Answer:
(d) Newton

Question 50.
The force of gravitation between two bodies does not depend on:
(a) product of their masses
(b) their separation
(c) sum of their masses
(d) gravitational constant
Answer:
(c) sum of their masses

Question 51.
Law of gravitation is applicable to:
(a) heavy bodies only
(b) small sized objects
(c) light bodies
(d) objects of any size
Answer:
(d) objects of any size

Question 52.
The value of gravitational constant (G) is:
(a) different at different places
(b) same at all places in the universe
(c) different at all places of earth
(d) same only at all the places of earth
Answer:
(b) same at all places in the universe

Question 53.
The unit of gravitational constant is:
(a) Nm² kg
(b) kgms^-2
(c) Nm² kg^-2
(d) ms^-2
Answer:
(c) Nm² kg^-2

Question 54.
The weight of an object is:
(a) the quantity of matter it contains
(b) its inertia
(c) same as its mass
(d) the force with which it is attracted by the earth
Answer:
(d) the force with which it is attracted by the earth

Question 55.
In vacuum, all freely failing objects have the same:
(a) speed
(b) velocity
(c) force
(d) acceleration
Answer:
(d) acceleration

Question 56.
The acceleration due to gravity:
(a) has the same value everywhere in space
(b) has the same value everywhere on earth
(c) varies with the latitude on earth
(d) is greater on moon due to its smaller diameter
Answer:
(c) varies with the latitude on earth

Question 57.
When an object is thrown up, the force of gravity:
(a) is opposite to the direction of motion
(b) is in the same direction as direction of motion
(c) decreases as it rises up
(d) increases as it rises up
Answer:
(a) is opposite to the direction of motion

Question 58.
The SI unit of acceleration due to gravity ‘g’ is:
(a) ms^-1
(b) ms
(c) ms^-2
(d) ms²
Answer:
(c) ms^-2

Question 59.
What happens to the value of ‘g’ as we go higher from surface of earth?
(a) decreases
(b) increases
(c) no change
(d) zero
Answer:
(a) decreases

Question 60.
Mass of a body on moon is:
(a) the same as that on the earth
(b) \(\frac{1}{6}\)th of that at the surface of the earth
(c) 6 times as that on the earth
(d) none of these
Answer:
(a) the same as that on the earth

Question 61.
At which place is the value of ‘g’ is zero?
(a) at poles
(b) at centre of the earth
(c) at equator
(d) above the earth
Answer:
(b) at centre of the earth

Question 62.
The weight of the body is maximum:
(a) at the centre of the earth
(b) on the surface of earth
(c) above the surface of earth
(d) none of the above
Answer:
(b) on the surface of earth

Question 63.
A rock is brought from the surface of the moon to the earth, then its:
(a) weight will change
(b) mass will change
(c) both mass and weight will change.
(d) mass and weight will remain the same
Answer:
(a) weight will change

Question 64.
Why is the acceleration due to gravity on the surface of the moon is lesser than that on the surface of earth?
(a) because mass of moon is less
(b) radius of moon is less
(c) mass and radius of moon is large
(d) mass and radius of moon is less
Answer:
(d) mass and radius of moon is less

Question 65.
if the distance between two bodies is doubled, then the gravitational force between them is:
(a) halved
(b) doubled
(c) reduced to one-fourth
(d) increased by one fourth
Answer:
(c) reduced to one-fourth

Question 66.
The unit newton can also be written as:
(a) kgm
(b) kgms^-1
(c) kgms^-2
(d) kgm^-2s
Answer:
(c) kgms^-2

Question 67.
A bus starts for rest and moves after 4 seconds. Its velocity is 100 ms 1. Its uniform acceleration is:
(a) 10 ms^-2
(b) 25 ms^-2
(c) 400 ms^-2
(d) 2.5 ms^-2
Answer:
(b) 25 ms^-2

Question 68.
A body of mass 10 kg increases its velocity from 2 m/s to 8 m/s within 4 second by the application of a constant force. The magnitude of the applied force is:
(a) 1.5 N
(b) 30 N
(c) 15 N
(d) 150 N
Answer:
(c) 15 N

Question 69.
The moment of force in clockwise direction is the moment in the anticlockwise direction.
(a) equal to
(b) lesser than
(c) greater than
(d) none
Answer:
(a) equal to

Question 70.
Which one of the following is scalar quantity?
(a) momentum
(b) moment of force
(c) speed
(d) velocity
Answer:
(c) speed

Question 71.
Which of the following changes the direction of motion of a body?
(a) momentum
(b) force
(c) energy
(d) mass
Answer:
(b) force

Question 72.
When one makes a sharp turns while driving a car he tends to lean sideways due to:
(a) inertia
(b) inertia of rest
(c) inertia of motion
(d) inertia of direction
Answer:
(d) inertia of direction

Question 73.
The unit of momentum is:
(a) kg m
(b) m/s²
(c) kg m/s
(d) joule
Answer:
(c) kg m/s

Question 74.
Moment of a force is given by τ =
(a) \(\frac{F}{d}\)
(b) F × 2d
(c) \(\frac{F}{d}\)
(d) F × d
Answer:
(d) F × d

Question 75.
Which of the following work on the principle of torque?
(a) Gears
(b) Seasaw
(c) steering wheel
(d) all the above
Answer:
(d) all the above

Question 76.
The SI unit of gravitational constant
(a) Nm²/g
(b) Nm²kg²
(c) Nm²/g^-2
(d) Nmkg
Answer:
(c) Nm²/g^-2

Question 77.
What is the value of gravitational constant?
(a) 6.674 × 10^-11 Nm²/g^-2
(b) 9.8 × 10^-11 Nm²/g^-2
(c) 6.647 × 10^-11 Nm²/g^-2
(d) 13.28 × 10^-11 Nm²/g^-2
Answer:
(a) 6.674 × 10^-11 Nm²/g^-2

Question 78.
The value of mass of the Earth is:
(a) 6.972 × 10²⁴ kg
(b) 6.792 × 10²⁴ kg
(c) 5.972 × 10²⁴ kg
(d) 2.936 × 10²⁴ kg
Answer:
(c) 5.972 × 10²⁴ kg

Question 79.
At poles of the Earth, weight of the body is:
(a) minimum
(b) maximum
(c) zero
(d) infinity
Answer:
(b) maximum

Question 80.
Where will the value of acceleration due to gravity be minimum?
(a) poles of the earth
(b) centre of the earth
(c) equator of the earth
(d) space
Answer:
(d) space

Question 81.
When an elevator is at rest:
(a) Apparent weight is greater than the actual weight
(b) Apparent weight is less than the actual weight
(c) Apparent weight is equal to the actual weight
(d) None of the above
Answer:
(c) Apparent weight is equal to the actual weight

Question 82.
In a lift, apparent weight of a body is equal to zero when the lift is;
(a) at rest
(b) moving upwards
(c) moving downwards
(d) falling down freely
Answer:
(d) falling down freely

Question 83.
When the lift is moving upward with an acceleration ‘o’ the apparent weight of the body is:
(a) lesser than actual weight
(b) greater than actual weight
(c) equal to actual weight
(d) zero
Answer:
(b) greater than actual weight

Question 84.
When an elevator is moving downward, the apparent weight of a person who is in that elevator is:
(a) maximum
(b) zero
(c) minimum
(d) infinity
Answer:
(c) minimum

Question 85.
Which law helps to predict the path of the astronomical bodies?
(a) Newton’s law of motion
(b) Newton’s law of gravitation
(c) Newton’s law of cooling
(d) Pascal’s law
Answer:
(b) Newton’s law of gravitation

II. Fill in the blanks.

1. If force – mass × acceleration, then momentum = ………
2. If liquid hydrogen is for rocket, then …….. is for MRI.
3. Inertia: (f) Mass then momentum: ……… Recoil of the gun: (ii) Newton’s third law: then flight of Jet Planes and Rockets: ………
4. Newton’s first law of motion: definition of force and inertia then Newton’s third law of motion: ….(i)….. while Newton’s second law of motion: ……(ii)…….
5. Newton’s first law: qualitative definition of force Newton’s second law: …..(i)…… The value of g: 9.8 ms-2 then Gravitational constant: …..(ii)……
6. Force: vector then momentum: …….(i)……. Balanced force: resultant of the two forces is zero then……(ii)…….. : resultant forces are responsible for change in position or state.
7. Momentum is the product of …….. and …….
8. To produce an acceleration of 1 m/s² in an object of mass 1 kg. The force required is ……… and for 3 kg of mass to produce same acceleration, the force required is ……….
9. Two or more forces are acting in an object and does not change its position, the forces are ………. and it is essential to act some ………. force, to change the state or position of an object.
10. ……… deals with bodies that are at rest under the action of force.
11. A branch of mechanics that deals with the motion of the bodies considering the cause of motion is called ………
12. If m is the mass of a body moving with velocity v then its momentum is given by P = ……..
13. A system of forces can be brought to equilibrium by applying ………. in opposite direction.
14. Torque is a ……… quantity.
15. Steering wheel transfers a torque to the wheels with ………..
16. The mathematical form of the principle of moments is ………..
17. Change in momentum takes place in the ………. of ………
18. 1 Newton = ……..
19. If a force F acts on a body for a time t’s then the impulse is ………
20. 1 kg f = ………
21. The force of attraction between two objects is directly proportional to the product of their ……. and inversely proportional to the square of the ………. between them.
22. The value of g varies with ……… and ………
23. The value of gravitational constant is ……… at all places but the value of acceleration due to gravity ………..
24. The relation between g and G is ………
Answer:
1. mass × velocity
2. liquid helium
3. (i) Mass and velocity, (ii) Law of conservation of momentum
4. (i) Law of conservation of momentum, (ii) Measure of force
5. (i) Quantitative definition of force, (ii) 6.673 × 10^-11 Nm²kg^-2
6. (i) vector, (ii) imbalanced force
7. mass, velocity
8. 1 N, 3 N
9. balanced, unbalanced
10. Statics
11. kinetics
12. mv
13. equilibriant
14. vector
15. less effort
16. F₁ × d₁ = F₂ × d₂
17. direction, force
18. 10⁵ dyne
19. I = F × t
20. 9.8 N
21. masses, distance
22. altitude, depth
23. same, differs
24. g = \(\frac{GM}{R^2}\)

III. State whether the following statements are true or false. Correct the statement if it is false.

1. Newton’s first law explains inertia:
2. If a motion depends on force then it is called as natural motion.
3. The resistance of a body to change its state of motion is known as inertia of motion.
4. Linear momentum = mass × acceleration.
5. Two equal force acting in opposite directions are called unlike parallel forces.
6. If the resultant force of three force acting on body is zero then the forces are called balanced forces.
7. Torque is a scalar quantity.
8. Moment of couple = Force × ⊥r distance between line of action of forces
9. Principle of moments states that moment in clockwise direction = Moment in anti clockwise direction.
10. 1 Newton = 1 g cm s^-2
11. Impulse = Force
12. Propulsion of rockets is based Newton’s third law of motion and conservation of linear momentum.
13. The value of universal gravitational constant is 6.674 × 10^-11 Nm² kg^-2
14. The relation between g and G is g = \(\frac{Gm}{R^2}\)
15. The value of acceleration due to gravity decreases as the altitude of the body increases.
16. In a ‘free fall’ motion acceleration of the body is equal to the acceleration due to gravity.
Answer:
1. True
2. False – If a motion does not depend on force then it is called as natural motion.
3. True
4. False – Linear momentum = mass × velocity
5. True
6. True
7. False – Torque is a vector quantity
8. True
9. True
10. False – 1 Newton = 1 kg ms^-2
11. False – Impulse = Change in momentum
12. True
13. True
14. False – The relation between g and G is g = \(\frac{GM}{R^2}\)
15. True
16. True

IV. Match the following.

Question 1.
Match the column A with column B.

Answer:
A. (iv)
B. (i)
C. (iii)
D. (v)
E. (ii)

Question 2.
Match the column A with column B.

Answer:
A. (iv)
B. (v)
C. (ii)
D. (i)
E. (iii)

Question 3.
Match the column A with column B.

Answer:
A. (ii)
B. (iv)
C. (v)
D. (i)
E. (iii)

Question 4.
Match the column A with column B.

Answer:
A. (iv)
B. (v)
C. (i)
D. (ii)

V. Assertion and Reasoning.

Question 1.
Assertion: While travelling in a motor car we tend to remain at rest with respect to the seat.
Reason: While travelling in a motor car we tend to move along the car with respect to the ground.
(a) Both Assertion and Reason are false.
(b) Assertion is true but Reason is false.
(c) Assertion is false but Reason is true.
(d) Both Assertion and Reason are true.
Answer:
(d) Both Assertion and Reason are true.

Question 2.
Assertion: When we kick a football it will roll over; when we kick a stone of the size of the football, it remains unmoved.
Reason: Inertia of a body depends mainly on its mass.
(a) Both Assertion and Reason are true and Reason explains Assertion.
(b) Both Assertion and Reason are true but Reason doesn’t explain Assertion.
(c) Both Assertion and Reason are false.
(d) Assertion is true but Reason is false.
Answer:
(a) Both Assertion and Reason are true and Reason explains Assertion.

Question 3.
Assertion: In a gun-bullet experiment, the acceleration of the gun is much lesser than the acceleration of the bullet.
Reason: The gun has much smaller mass than the bullet.
(a) Both Assertion and Reason are false.
(b) Assertion is true but Reason is false.
(c) Assertion is false but Reason is true.
(d) Both Assertion and Reason are true.
Answer:
(b) Assertion is true but Reason is false.

Question 4.
Assertion: When a bullet is fired from a gun, the bullet moves forward, the gun moves backward.
Reason: Total momentum before collision is equal to the total momentum .after collision.
(a) Both Assertion and Reason are true and Reason explains Assertion.
(b) Both Assertion and Reason are true but Reason doesn’t explain Assertion.
(c) Assertion is true but Reason is false.
(d) Assertion is false but Reason is true.
Answer:
(b) Both Assertion and Reason are true but Reason doesn’t explain Assertion.

Question 5.
Assertion: A person whose mass on earth is 125 kg will have his mass on moon as 250 kg.
Reason: Mass varies from place to place.
(a) Both Assertion and Reason are true and Reason explains Assertion.
(b) Both Assertion and Reason are true but Reason doesn’t explain Assertion.
(c) Both Assertion and Reason are false.
(d) Assertion is true but Reason is false.
Answer:
(c) Both Assertion and Reason are false.

Question 6.
Assertion: During turning a cyclist negotiates of the curve, while a man sitting in the car leans outwards of the curve.
Reason: An acceleration is acting towards the centre of the curve.
(a) If both the assertion and the reason are true and the reason is the correct explanation of assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of assertion.
(c) Assertion is true, but the reason is false.
(d) Assertion is false, but the reason is true.
Answer:
(c) Assertion is true, but the reason is false.

Question 7.
Assertion: On a rainy day, it is difficult to drive a car at high speed.
Reason: The valve of coefficient of friction is lowered due to polishing of the surface.
(a) If both the assertion and the reason are true and the reason is the correct explanation of assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of assertion.
(c) Assertion is true, but the reason is false.
(d) Assertion is false, but the reason is true.
Answer:
(a) If both the assertion and the reason are true and the reason is the correct explanation of assertion.

Question 8.
Assertion: A rocket moves forward by pushing the air backwards.
Reason: It derives the necessary thrust to move forwarded according to Newton’s third law of motion.
(a) If both the assertion and the reason are true and the reason is the correct explanation of assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of assertion.
(c) Assertion is true, but the reason is false.
(d) Assertion is false, but the reason is true.
Answer:
(a) If both the assertion and the reason are true and the reason is the correct explanation of assertion.

Question 9.
Assertion: A mass in the elevator which is falling freely, does not experience gravity.
Reason: Inertial and gravitational masses have equivalence.
(a) If both the assertion and the reason are true and the reason is the correct explanation of assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of assertion.
(c) Assertion is true, but the reason is false.
(d) Assertion is false, but the reason is true.
Answer:
(c) Assertion is true, but the reason is false.

Question 10.
Assertion: The intensity of gravitational field varies with respect to height and depth of a body on the Earth.
Reason: The value of gravitational field intensity depends on height and depth of a body.
(a) If both the assertion and the reason are true and the reason is the correct explanation of assertion.
(b) If both the assertion and the reason are true, but the reason is not the correct explanation of assertion.
(c) Assertion is true, but the reason is false.
(d) Assertion is false, but the reason is true.
Answer:
(d) Assertion is false, but the reason is true.

VI. Answer briefly.

Question 1.
What is meant by mechanics? How can it be classified?
Answer:
Mechanics is the branch of physics that deals with the effect of force on bodies. It is divided into two branches namely statics and dynamics.

Question 2.
What is statics?
Answer:
Statics deals with the bodies, which are at rest under the action of forces.

Question 3.
What is dynamics?
Answer:
Dynamics is the study of moving bodies under the action of forces.

Question 4.
What is Kinematics?
Answer:
Kinematics deals with the motion of bodies without considering the cause of motion.

Question 5.
What is Kinetics?
Answer:
Kinetics deals with the motion of bodies considering the cause of motion.

Question 6.
Define momentum. State its unit.
Answer:
The product of mass and velocity of a moving body gives the magnitude of linear momentum. It acts in the direction of the velocity of the object.
Its S.I unit is kg ms^-1.

Question 7.
What is meant by a force?
Answer:
Force is one that changes or tends to change the state of rest or of uniform motion of a body.

Question 8.
State the effects of force.
Answer:

1. Produces or tries to produce the motion of a static body.
2. Stops or tries to stop a moving body.
3. Changes or tries to change the direction of motion of a moving body.

Question 9.
What is resultant force?
Answer:
When several forces act simultaneously on the same body, then the combined effect of the multiple forces can be represented by a single force, which is termed as ‘resultant force’.

Question 10.
What are balanced forces?
Answer:
If the resultant force of all the forces acting on a body is equal to zero, then the body will be in equilibrium. Such forces are called balanced forces.

Question 11.
What are unbalanced forces?
Answer:
Forces acting on an object which tend to change the state of rest or of uniform motion of it are called unbalanced forces.

Question 12.
What is meant by equilibriant?
Answer:
A system can be brought to equilibrium by applying another force, which is equal to the resultant force in magnitude, but opposite in direction. Such force is called as ‘Equilibriant’.

Question 13.
What is meant by couple? State few examples.
Answer:
Two equal and unlike parallel forces applied simultaneously at two distinct points constitute a couple. The line of action of the two forces does not coincide.
Eg: Turning a tap, winding or unwinding a screw, spinning of a top, etc.

Question 14.
A sudden application of brakes may cause injury to passengers in a car by collision with panels in front?
Answer:
With the application of brakes, the car slows down but our body tends to continue in the same state of motion because of inertia.

Question 15.
When we are standing in a bus which begins to move suddenly, we tend to fall backwards. Why?
Answer:
This is because a sudden start of the bus brings motion to the bus as well as to our feet in contact with the floor of the bus. But the rest of our body opposes this motion because of its inertia.

Question 16.
While travelling through a curved path, passengers in a bus tend to get thrown to one side. Justify.
Answer:
When an unbalanced force is applied by the engine to change the direction of motion of the bus, passengers move to one side of the seat due to inertia of their body.

Question 17.
Define momentum of an object.
Answer:
The momentum of an object is defined as the product of its mass and velocity.

Question 18.
Define One newton.
Answer:
The amount of force required for a body of mass 1 kg produces an acceleration of 1 ms^-2, 1 N = 1 kg ms^-2.

Question 19.
Define one dyne.
Answer:
The amount of force required for a body of mass 1 gram produces an acceleration of 1 cm s^-2, 1 dyne = 1 g cm s^-2; also
1 N = 10⁵ dyne.

Question 20.
What is unit force?
Answer:
The amount of force required to produce an acceleration of 1 ms^-2 in a body of mass 1 kg is called ‘unit force’.

Question 21.
What are the values of 1 kg f and 1 g f.
Answer:
1 kg f= 1 kg × 9.8 m s^-2 = 9.8 N;
1 g f = 1 g × 980 cm s^-2 = 980 dyne

Question 22.
What is meant by impulsive force?
Answer:
A large force acting for a very short interval of time is called as ‘Impulsive force’.

Question 23.
What is meant by impulse?
Answer:
When a force F acts on a body for a period of time t, then the product of force and time is known as ‘impulse’ represented by ‘J’
Impulse, J = F × t

Question 24.
Prove that impulse is equal to the magnitude of change in momentum.
Answer:
By Newton’s second law,
F = ΔP/t (Δ refers to change)
ΔP = F × t
J = ΔP
F × t = ΔP
Impulse is also equal to the magnitude of change in momentum. Its unit is kg ms^-1 or N s.

Question 25.
How can the change in momentum be achieved?
Answer:
Change in momentum can be achieved in two ways. They are:

1. A large force acting for a short period of time and
2. A smaller force acting for a longer period of time.

Question 26.
State an example for change in momentum.
Answer:
Automobiles are fitted with springs and shock absorbers to reduce jerks while moving on uneven roads.

Question 27.
A spring balance is fastened to a wall and another spring balance is attached to its hole and is pulled steadily. Do both the spring balances show different readings on their scales. Give reason.
Answer:
No, both the spring balances show same reading. Because both action and reaction are equal and opposite.

Question 28.
When a gun is fired it recoils, Give reason.
Answer:
When a gun is fired it exerts forward force on the bullet. The bullet exerts an equal and opposite reaction force on the gun. This results in the recoil of the gun.

Question 29.
Action and reaction are equal and opposite. But they do not cancel each other. Give reason.
Answer:
They do not cancel each other because they never act on the same body. Since they act on different bodies, they do not cancel each other.

Question 30.
Why does a cricket player, pulls his arms back with the ball while catching a ball?
Answer:
(i) The cricket player stops the speeding ball suddenly in a very short time. The high value of velocity of the ball will be decreased to zero, in a very short time and it will result in a high retardation.
(ii) When the player pulls his arms with the ball, he increases the value of time and so retardation is also decreased and retardation force is lesser than before and the palm of player is not hurt.

Question 31.
When a sailor jumps forward, the boat moves backward. State the action and reaction in the above case.
Answer:
Action – a sailor jumps forward.
Reaction – movement of the boat.

Question 32.
It is easier to stop a tennis ball than a cricket ball moving with the same velocity.
Answer:
This is because the mass of tennis ball is less than the cricket ball. So it has lesser momentum and hence smaller force is required to stop the tennis ball.

Question 33.
Define moment of force.
Answer:
The magnitude of the moment of force about a point is defined as the product of the magnitude of force and perpendicular distance of the point from the line of action of the force.

Question 34.
Draw the diagram of a couple.
Answer:

Question 35.
What do you know about moment of a couple?
Answer:
Moment of a couple is the product of force and perpendicular distance between the line of action of forces.
M = F × S

Question 36.
It is easier to open a door by applying the force at the free end. Justify.
Answer:
(i) If the force is applied at the handle of the door to open it, only small force is required. That means larger the perpendicular distance, lesser is the force needed to turn the body.

(ii) From this it is easy to conclude that the turning effect of a body about an axis depends not only on the magnitude of the force but also on the perpendicular distance of the line of action of the applied force from the axis of rotation.

Question 37.
A force can rotate a nut when applied by a wrench.
Answer:
(a) What is meant by moment of force?
Answer:
The turning effect of force acting on a body about an axis is called the moment of force.

(b) Name the factors on which the turning effect of a force depend on.
Answer:
Turning effect of force depends on-

1. The magnitude of the force applied and
2. The distance of line of action of the force from the axis of rotation.

Question 38.
What is meant by weightlessness?
Answer:
Whenever a body or a person falls freely under the action of Earth’s gravitational force alone, it appears to have zero weight. This state is referred to as ‘weightlessness’.

Question 39.
What is meant by moment of a force?
Answer:
The turning effect of force acting on a body about an axis is called moment of force.

Question 40.
What is meant by gravitational force?
Answer:
The gravitational force is the force of attraction between objects in the universe.

Question 41.
In which direction does gravitational force act?
Answer:
The gravitational force acts along the line joining the centres of two objects.

Question 42.
(a) When a horse suddenly starts running, the rider falls backward. Give reason.
Answer:
This is because the lower part of the rider which is in contact with the horse, comes into motion. While his upper part tends to remain at rest due to inertia.

(b) Coin falls into the tumbler when the card is given a sudden jerk. State the fact that is utilized in this illustration.
Answer:
inertia.

Question 43.
(a) Why it is difficult to walk on a slippery floor or sand?
Answer:
Because we are unable to push (action) such a ground sufficiently hard. As a result, the force of reaction is not sufficient to help us to move forward.

(b) State the law related to this.
Answer:
Newton’s third law of motion.

Question 44.
State the numerical value and unit of gravitational constant.
Answer:
The numerical value of gravitational constant is 6.673 × 10^-11 Nm² kg^-2.
Its unit is Nm² kg^-2.

Question 45.
What is meant by acceleration due gravity?
Answer:
The acceleration produced in a body on account of the force of gravity is called acceleration due to gravity.

Question 46.
Write the expression of acceleration due to gravity.
Answer:
Acceleration due to gravity g = \(\frac{GM}{R^2}\)
where G is gravitational constant.
M is the mass of the earth.
R is radius of the earth.

Question 47.
Deduce the value of mass of earth.
Answer:
Mass of earth M = \(\frac{gR^2}{G}\)
g = 9.8 m/s²
R = 6.38 × 10⁶ m
G = 6.673 × 10^-11 Nm² kg^-2

= 5.98 × 10²⁴ kg

Question 48.
What happens to the gravitational force between two objects if the masses of both objects are doubled?
Answer:
If the masses of both objects are doubled, then gravitational force between them will be increased to four times.

Question 49.
The mass of a body is 60 kg. What will be its mass when it is placed on the moon?
Answer:
The mass of a body on the moon is 60 kg. There will be no change in mass because it is still made up of same amount of matter.

Question 50.
When an object is taken to the moon, is there any change in weight?
Answer:
Yes. The weight of a object will be decreased because the gravitational force is weak i.e., the value of acceleration due to gravity becomes less on the moon.

Question 51.
Gravitational force acts on all objects is proportional to their masses. But a heavy object falls slower than a light object. Give reason.
Answer:
It is true that gravitational force between all objects are in proportion to their masses. But in free fall of objects, acceleration produced in a body is due to gravitational force is independent of mass of object that’s why a heavy object does not fall faster.

Question 52.
A falling apple is attracted towards the earth.
(a) Does the apple attract the earth?
Answer:
Yes. According to Newton’s third Law. The apple attracts the earth.

(b) Why doesn’t earth move towards an apple?
Answer:
According to Newton’s second Law, for a given force, acceleration a ∝ \(\frac{1}{m}\). Here mass of an apple is negligibly small compared to earth. So we cannot see the earth moving towards an apple.

Question 53.
Observe the figure and write the answer:
Answer:

(a) The force which balance A exerts on balance B is called …….
Answer:
The force which balance A exerts on balance B is called action.

(b) The force of balance B on balance A is called ……..
Answer:
The force of balance B on balance A is called opposite reaction.

Question 54.
What is meant by apparent weight?
Answer:
Apparent weight is the weight of the body acquired due to the action of gravity and other external forces acting on the body.

Question 55.
What is meant by free fall?
Answer:
When the person in a lift moves down with an acceleration (a) equal to the , acceleration due to gravity (g), i.e., when a = g, this motion is called as ‘free fall’. Here, the apparent weight (R = m (g – g) = 0) of the person is zero.

VII. Solve the given problems.

Question 1.
The ratio of masses of two bodies is 1 : 3 and the ratio of applied forces on them is 4 : 9. Calculate the ratio of their accelerations.
Answer:
Ratio of masses m₁ : m₂ = 1 : 3
Ratio of applied forces F₁ : F₂ = 4 : 9
Accelerations a = \(\frac{F}{m}\)
Acceleration of first body,
a₁ = \(\frac{F_1}{m_1}\)
= \(\frac{4}{1}\) = 4
Acceleration of second body,
a₂ = \(\frac{F_2}{m_2}\)
Ratio of their accelerations is 4 : 3

Question 2.
What is acceleration produced by a force of 12 N exerted on an object of mass 3 kg?
Answer:
F = 12 N; m = 3 kg ; a = ?
F = ma; a = F/m = \(\frac{4}{1}\) = 4 m/s²
The acceleration produced a = 4 m/s².

Question 3.
A certain force exerted for 1.2 s raises the speed of an object from 1.8 m/s to 4.2 m/s. Later, the same force is applied for 2 s. How much does the speed change in 2 s.
Answer:
t = 1.2 s; u = 1.8 m/s; v = 4.2 m/s
acceleration a = \(\frac{v-u}{t}\)
= \(\frac{4.2-1.8}{1.2}\) = \(\frac{2.4}{1.2}\)
= 2 m/s²
Now, the force applied is the same, it will produce the same acceleration.
Change in speed = acceleration × time for which force is applied.
= 2 × 2 = 4 m/s
Change in speed = 4 m/s.

Question 4.
A constant force acts on an object of mass 10 kg for a duration of 4 s. It increases the objects velocity from 2 ms^-1 to 8 ms^-1. Find the magnitude of the applied force.
Answer:
Mass of an object m = 10 kg
Initial velocity u = 2 ms^-1
Final velocity v = 8 ms^-1
We know, force F = \(\frac{m(v-u)}{t}\)
F = \(\frac{10(8-2)}{4}\)
= \(\frac{10×6}{4}\)
= 15 N

Question 5.
Which would require a greater force for accelerating a 2 kg of mass at 4 ms^-2 or a 3 kg mass at 2 ms^-2?
Answer:
We know, force F = ma
Given m₁ = 2 kg a₁ = 4 ms^-2
m₂ = 3 kg a₂ = 2 ms^-2
F₁ = m₁ a₁ = 2 × 4 = 8 N
F₂ = m₂ a₂ = 3 × 2 = 6 N
∴ F₁ > F₂.
Thus, accelerating 2 kg mass at 4 ms^-2 would require a greater force.

Question 6.
A bullet of mass 15 g is horizontally fired with a velocity 100 ms^-1 from a pistol of mass 2 kg. What is the recoil velocity of the pistol?
Answer:
The mass of the bullet, m₁ = 15 g = 0.015 kg
Mass of the pistol, m₂ = 2 kg
Initial velocity of the bullet, u₁ = 0
Initial velocity of the pistol, u₂ = 0
Final velocity of the bullet, v₁ = + 100 ms^-1
(The direction of the bullet is taken from left to right-positive, by convention) Recoil velocity of the pistol = v₂
Total momentum of the pistol and bullet before firing.
= m₁ u₁ + m₂ u₁
= (0.015 × 0) + (2 × 0)
= 0
Total momentum of the pistol and bullet after firing.
= m₁ v₁ + m₂ v₂
= (0.015 × 100) + (2 × v₂)
= 1.5 + 2v₂
According to the law of conservation of momentum,
Total momentum after firing = Total momentum before firing.
1.5 + 2v₂ = 0
2v₂ = -1.5
v₂ = – 0.75 ms^-1
Negative sign indicates that the direction in which the pistol would recoil is opposite to that of the bullet, that is, right to left.

Question 7.
A 10 g bullet is shot from a 5 kg gun with a velocity of 400 m/s. what is the speed of recoil of the gun?
Answer:
Mass of bullet, m₁ = 10 g
= 10 × 10^-3 kg = 10^-2 kg
Mass of gun, m₂ = 5 kg
Velocity of bullet, v₁ = 400 m/s
speed of recoil of gun v₂ = ?
Total momentum of bullet and gun after firing = total momentum before firing.
m₁ v₁ + m₂ v₂ = 0
v₂ = –\(\frac{m_1 v_1}{m_2}\)
= \(\frac{-10_{-2}×400}{5}\) = -0.8 m/’s.
The speed of recoil of the gun v₂ = -0.8 m/’s.
Negative sign shows that the gun moves in a direction opposite to that of the bullet.

Question 8.
The figure represents two bodies of masses 10 kg and 20 kg, moving with an initial velocity of 10 ms^-1 and 5 ms^-1 respectively. They collide with each other. After collision, they move with velocities 12 ms^-1 and 4 ms^-1 respectively. The time of collision is 2 s. Now calculate F₂ and F₂.
Answer:

m₁ = 10 kg
m₂ = 20 kg
u₁ = 10 ms^-1
u₂ = 5 ms^-1
v₁ = 12 ms^-1
v₂ = 4 ms^-1
Time of collision, t = 2 s
∴ Force acting on 20 kg object
F₁ = m₂ (\(\frac{v_2-u_2}{t}\))
= 20(\(\frac{4-5}{2}\))
F₁ = -10 N
Force acting on 10 kg object
F₂ = m₁ (\(\frac{v_1-u_1}{t}\))
= 10(\(\frac{12-10}{2}\))
F₂ = 10 N

Question 9.
The mass of an object is 5 kg. What is its weight on the earth?
Answer:
Mass, m = 5 kg
Acceleration due to gravity,
g = 9.8 ms^-2
Weight, W = m × g
W = 5 × 9.8 = 49 N
Therefore, the weight of the object is 49 N.

Question 10.
Calculate the force of gravitation between two objects of masses 80 kg and 120 kg kept at a distance of 10 m from each other. Given, G = 6.67 × 10^-11 Nm² / kg².
Answer:
m₁ = 80 kg, m₂ = 120 kg, r = 10 m,
G = 6.67 × 10^-11 Nm² / kg², F = ?

= 64.032 × 10^-10 N
The force of gravitation between two objects = 64.032 × 10^-10 N.

Question 11.
Calculate the value of acceleration due to gravity on moon. Given mass of moon = 7.4 × 10²² kg. radius of moon = 1740 km.
Answer:

= 1.63 ms²
The acceleration due to gravity = 1.63 ms^-2.

Question 12.
State Newton’s law of gravitation. Write an expression for acceleration due to gravity on the surface of the earth. If the ratio of acceleration due to gravity of two heavenly bodies is 1 : 4 and the ratio of their radii is 1 : 3, what will be the ratio of their masses?
Answer:
Newton’s law of gravitation states that every object in the universe attracts every other object with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
F = \(\frac{Gm_{1}m_{2}}{d^{2}}\)
Acceleration due to gravity g = \(\frac{GM}{R^{2}}\)
Where G is gravitational constant
M is the mass of the earth
R is radius of the earth
Ratio of acceleration due to gravity = 1 : 4
Ratio of radii of two bodies = 1 : 3
Acceleration due to gravity is g

Dividing Equation (1) by equation (2) we get

∴ M₁ : M₂ = 1 : 36
∴ Ratio of their masses = 1 : 36

Question 13.
A bomb of mass 3 kg, initially at rest, explodes into two parts of 2 kg and 1 kg. The 2 kg mass travels with a velocity of 3 m/s. At what velocity will the 1 kg mass travel?
Answer:
Mass of a bomb m = 3 kg
Initial velocity of the bomb v = 0
Mass of the first part m₁ = 2 kg
Velocity of the first part v₁= 3 m/s
Mass of the second part m₂ = 1 kg
Let the velocity of the second part be v₂.
By the law of conservation of momentum
mv = m₁ v₁ + m₂ v₂
3 × 0 = 2 × 3 + 1 × v₂
0 = 6 + v₂
∴ v₂ = -6 m/s
Velocity of the 1 kg mass = -6 m/s

Question 14.
Two ice skaters of weight 60 kg and 50 kg are holding the two ends of a rope. The rope is taut. The 60 kg man pulls the rope with 20 N force. What will be the force exerted by the rope on the other person? What will be their respective acceleration?
Answer:
Mass of first ice skater = 50 kg
Mass of second ice skater = 60 kg
Force applied by second ice skater = 20 N
When the rope is taut, the force exerted by the rope on the other person is 20 N.

= 0.33 m/s²

VIII. Answer in detail.

Question 1.
Explain the types of forces.
Answer:
Based on the direction in which the forces act, they can be classified into two types as:
1. Like parallel forces : Two or more forces of equal or unequal magnitude acting along the same direction, parallel to each other are called like parallel forces.
2. Unlike parallel forces : If two or more equal forces or unequal forces act along opposite directions parallel to each other, then they are called unlike parallel forces.

Question 2.
Tabulate the action of forces with their resultant and diagram.
Answer:

Question 3.
Explain the applications of torque.
Answer:
1. Gears : A gear is a circular wheel with teeth around its rim. It helps to change the speed of rotation of a wheel by changing the torque and helps to transmit power.

2. Seasaw : Most of you have played on the seasaw. Since there is a difference in the weight of the persons sitting on it, the heavier person lifts the lighter person. When the heavier person comes closer to the pivot point (fulcrum) the distance of the line of action of the force decreases. It causes less amount of torque to act on it. This enables the lighter person to lift the heavier person.

3. Steering Wheel : A small steering wheel enables you to manoeuore a car easily by transferring a torque to the wheels with less effort.

Question 4.
State and explain principle of moments.
Answer:
When a number of like or unlike parallel forces act on a rigid body and the body is in equilibrium, then the algebraic sum of the moments in the clockwise direction is equal to the algebraic sum of the moments in the anticlockwise direction. In other words, at equilibrium, the algebraic sum of the moments of all the individual forces about any point is equal to zero.

In the illustration given in figure, the force F₁ produces an anticlockwise rotation at a distance d₁ from the point of pivot P (called fulcrum) and the force F₂ produces a clockwise rotation at a distance d₂ from the point of pivot P. The principle of moments can be written as follows:
Moment of clockwise direction = Moment of anticlockwise direction
F₁ × d₁ = F₂ × d₂

Question 5.
Explain the illustrations for Newton’s third law of motion briefly.
Answer:
Newton’s third law states that ‘for every action, there is an equal and opposite reaction.They always act on two different bodies.
If a body A applies a force F_A on a body B, then the body B reacts with force F_B on the body A, which is equal to F_A in magnitude, but opposite in direction. F_B = -F_A
Eg:
(i) When birds fly they push the air downwards with their wings (Action) and the air pushes the bird upwards(Reaction).
(ii) When a person swims he pushes the water using the hands backwards (Action), and the water pushes the swimmer in the forward direction (Reaction).
(iii) When you fire a bullet, the gun recoils backward and the bullet is moving forward (Action) and the gun equalises this forward action by moving backward (Reaction).

Question 6.
Derive the relation between acceleration due to gravity (g) and Gravitational constant G.
Answer:

When a body is at rests on the surface of the Earth, it is acted upon by the gravitational force of the Earth. Let us compute the magnitude of this force in two ways. Let, M be the mass of the Earth and m be the mass of the body. The entire mass of the Earth is assumed to be concentrated at its centre. The radius of the Earth is R = 6378 km = 6400 km approximately. By Newton’s law of gravitation, the force acting on the body is given by
F = \(\frac{GMm}{R^2}\)
Here, the radius of the body considered is negligible when compared with the Earth’s radius. Now, the same force can be obtained from Newton’s second law of motion.
According to this law, the force acting on the body is given by the product of its mass and acceleration (called as weight). Here, acceleration of the body is under the action of gravity hence a = g
F = ma = mg …….. (1)
F = weight = mg ……… (2)
Comparing equations (1) and (2), we get
mg = \(\frac{GMm}{R^2}\)
Acceleration due to gravity g = \(\frac{GM}{R^2}\)

Question 7.
Tabulate the apparent weight of person moving in a lift when lift is
(i) moving upwards
(ii) moving downwards
(iii) at rest
(iv) falling down freely.
Answer:

IX. HOT Questions

Question 1.
What gives the measure of inertia?
Answer:
Mass of a body gives the measure of inertia.

Question 2.
Is any external force required to keep a body in uniform motion?
Answer:
No, external force is not required to keep a body in uniform motion.

Question 3.
Which law of motion gives the measure of force?
Answer:
Newton’s second law of motion.

Question 4.
Write the second law of motion in vector form.
Answer:
\(\vec { F } =m\vec { a }\)
Where, \(\vec { F }\) – force, m – mass, \(\vec { a }\) – acceleration.

Question 5.
What is the net force acting on a cork that floats on water? Why?
Answer:
The net force is zero, because the weight of the cork is balanced by the upthrust of water on it.

Question 6.
What is the relation between newton and dyne?
Answer:
1 newton = 105 dyne

Question 7.
A person is standing on a weighing machine placed nearly a door. What will be the effect of the reading of the machine if a person presses the edge of the door upward?
Answer:
The reading of the machine will increase.

Question 8.
A bomb explode in mid-air into two equal fragments. What is the relation between the direction of motion of the two fragments?
Answer:
The two fragments will fly off in exactly opposite directions.

Question 9.
Which law explains the following situation, Athlete runs a certain distance before long jump.
Answer:
Law of inertia which is Newton’s first law of motion.

Question 10.
Is impulse a scalar?
Answer:
No, impulse is a vector quantity.

Question 11.
When a lift moves with uniform velocity, what is its
(i) acceleration and
(ii) the apparent weight of the person standing inside the lift.
Answer:
(i) Acceleration of the lift is zero.
(ii) The apparent weight of a person standing inside the lift is equal to his true weight since R = mg.

Question 12.
When a lift falls freely, what happens to the apparent weight of a body in the lift.
Answer:
The apparent weight of the body in the lift is equal to zero. Since
R = m(g – g) = 0

Question 13.
When a body falls freely it appears to have zero weight. Give reason.
Answer:
When a body falls freely, it acts under the action of gravitational force alone. Hence it appears to have zero weight.