Category: Class 8

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf History Chapter 1 Advent of the Europeans Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions History Chapter 1 Advent of the Europeans

Samacheer Kalvi 8th Social Science Advent of the Europeans Text Book Back Questions and Answers

I. Choose the correct answer:
1. Who laid the foundation of Portuguese power in India?
a) Vasco da Gama
b) Bartholomew Diaz
c) Alfonso de Albuquerque
d) Almeida
Answer:
d) Almeida

2. Which of the following European Nation was the foremost attempt to discover a sea route to India?
a) Dutch
b) Portugal
c) France
d) Britain
Answer:
b) Portugal

3. In 1453 Constantinople was captured by ………………. .
a) The French
b) The Turks
c) The Dutch
d) The British
Answer:
b) The Turks

4. Sir William Hawkins belonged to ………………. .
a) Portugal
b) Spain
c) England
d) France
Answer:
c) England

5. The first fort constructed by the British in India was ………………. .
a) Fort William
b) Fort St.George
c) Agra fort
d) Fort St. David
Answer:
a) Fort William

6. Who among the following Europeans were the last to come India as traders?
a) The British
b) The French
c) The Danish
d) The Portuguese
Answer:
b) The French

7. Tranquebar on the Tamil Nadu coast was a trade centre of the ………………. .
a) The Portuguese
b) The British
c) The French
d) The Danish
Answer:
d) The Danish

II. Fill in blanks.
1. National Archives of India (NAI) is located in ……………….
Answer:
New Delhi

2. Bartholomew Diaz, a Portuguese sailor was patronized by ……………….
Answer:
King John – II

3. The printing press in India was set up by ………………. at Goa in 1556.
Answer:
Portuguese

4. The Mughal Emperor ………………. permitted the English to trade in India.
Answer:
Jahangir

5. The French East India Company was formed by ……………….
Answer:
Colbert

6. ………………. the King of Denmark issued a charter to create Danish East India company.
Answer:
Christian IV

III. Match the following.

1. The Dutch	a) 1664
2. The British	b) 1602
3. The Danish	c)1600
4. The French	d) 1616

Answer:

1. The Dutch	b) 1602
2. The British	c) 1600
3. The Danish	d)1616
4. The French	a) 1664

IV. State true or false.
1. Auto biography is one of the written sources.
Answer:
True

2. Coins are one of the material sources.
Answer:
True

3. Ananda Rangam was a translator served under British.
Answer:
False

4. The place where historical documents are preserved is called archives.
Answer:
True

V. Consider the following statements and tick (✓) appropriate answer.
1. i) Governor Nino de Cunha moved Portuguese capital from Cochin to Goa.
ii) Portuguese were the last to leave from India.
iii) The Dutch founded their first factory at Surat.
iv) Sir Thomas Roe was sent to Jahangir’s court by King James I of England.
a) i & ii are Correct.
b) ii & iv are Correct,
c) iii is correct.
d) i, ii & iv are correct.
Answer:
d) i, ii & iv are correct.

2. Find out the wrong pair:
1. Francis Day – Denmark
2. Pedro Cabral – Portugal
3. Captain Hawkins – Britain
4. Colbert – France
Answer:
1. Francis Day – Denmark

VI. Answer the following in one or two sentences.
1. Give a short note on Archives?
Answer:
Archives is the place where historical documents are preserved. The National Archives of India (NAI) is located in New Delhi. It is the chief storehouse of the records of the government of India.

2. Write about the importance of Coins.
Answer:
Coins are a good source to know about administrative history.

3. Why Prince Henry is called ‘Henry the Navigator’?
Answer:
Prince Henry of Portugal, who is commonly known as the “Navigator”, encouraged his countrymen to take up the adventurous life of exploring the unknown regions of the world.

4. Name the important factories established by the Dutch in India.
Answer:
Masulipatnam, Pulicat, Surat, Patna, Chinsura, Kasim bazaar, Nagapatnam, Balasore and Cochin.

5. Mention the trading centers of the English in India.
Answer:
The English had established their trading centres at Surat, Agra, Ahmadabad, and Broach.

VII. Answer the following.
1. Give an account of the sources of Modern India.
Answer:
1. The sources for the history of modem India help us to know the political, socio-economic and cultural developments in the country.

2. The Portuguese, the Dutch, the French, the Danes, and the English recorded their official transactions in India on state papers.

3. History can be written with the help of written sources and material sources.

4. Written Sources:
After the advent of the printing press, books were published in different languages people began to acquire knowledge easily in the fields like art, literature, history, and science.

5. Written sources include Literatures, Travel Accounts, Diaries, Auto Biographies, Pamphlets, Government Documents and Manuscripts.

6. Archives:
It has a main source of information for understanding past administrative machinery as well as a guide to the present and future generations related to all matters.

7. Material Sources:
Paintings and statues are the main sources of modem Indian history which provide information about national leaders and historical personalities and their achievements.

8. Historical buildings and museums preserve and promote our cultural heritage,

9. Coins are a good source to know about administrative history.

2. How did the Portuguese establish their trading centres in India?
Answer:

• During the 16th century, Portuguese succeeded in capturing Goa, Daman, Diu, Salsette, Bassein, Chaul and Bombay on the western coast, Hooghly on the Bengal coast and Santhome on the Madras coast and enjoyed good trade benefits.
• The Portuguese brought the cultivation of tobacco to India. Due to the influence of Portuguese spread Catholic religion spread on India’s western and eastern coasts.
• The printing press was set up by the Portuguese at Goa in 1556.
• A scientific work on the Indian medicinal plants by a European writer was printed at Goa in 1563.

3. How did the British establish their trading centres in India?
Answer:
1. In 1600, Elizabeth, the Queen of England granted a charter to the governor and company of Merchants of London to trade with the East Indies.

2. The Company was headed by a Governor and a court of 24 directors.

3. Captain Hawkins visited Jahangir’s court and secured permission to raise a settlement at Surat which was cancelled later.

4. In 1612, the English Captain Thomas Best, inflicted a severe defeat over the Portuguese in a naval battle near Surat.

5. The Mughal Emperor Jahangir permitted the English to establish their factory in 1613 at Surat, which became the headquarters of the English in western India.

6. Captain Nicholas Downton won another decisive victory over the Portuguese in 1614.

7. This enhanced the British prestige at the Mughal court.

8. In 1615, Sir Thomas Roe was sent to Jahangir’s court by King James I of England, who succeeded in concluding a commercial treaty with the emperor

9. Before the departure of Sir Thomas Roe, the English had established their trading centres at Surat, Agra, Ahmadabad, and Broach.

IX. HOTS.
1. How did the fall of Constantinople affect the European nations?
Answer:

1. The fall of Constantinople was the end of an era for Europe as it severely hurt traders in the European region.
2. The land route between India and Europe was closed. The Turks penetrated into North Africa and the Balkan Peninsula.
3. It became imperative on the part of the European nations to discover new sea routes to the East.

Samacheer Kalvi 8th Social Science Advent of the Europeans Additional Important Questions and Answers

I. Choose the correct answer.
1. The ……………… of India attracted Europeans to this country.
(a) Technology
(b) Machinery
(c) Wealth
(d) River
Answer:
(c) wealth

2. ……………….. was sent to the first governor for the Portuguese possessions in India.
a) Almeida
b) Vascoda Gama
c) Albu querque
d) Bartholomeu Diaz
Answer:
a) Almeida

3. In Pulicat, the fort built by the Dutch was …………………… .
a) Geldria Fort
b) St. George
c) William Fort
d) Red fort
Answer:
a) Geldria Fort

4. …………….. help to preserve and promote our cultural heritage.
(a) Parks
(b) Books
(c) Beaches
(d) Museums
Answer:
(d) Museums

5. A sailor who reached the southernmost point of Africa
a) Americo vesbuki
b) Bartholomew Diaz
c) Colombus
d) Macallan
Answer:
b) Bartholomew Diaz

6. The national Archives of India (NAI) in located in ……………… .
a) New Delhi
b) Chennai
c) Coimbatore
d) Thanjavur
Answer:
a) New Delhi

7. Who set up a printing press at Tranqueber (Tarangambadi)
a) G.U pope
b) Caldwell
c) John – d – Britto
d) Ziegenbalg
Answer:
d) Ziegenbalg

8. Battle of Plassey in the year ………………… .
a) 1757
b) 1758
c) 1759
d) 1760
Answer:
a) 1757

9. Battle of Buxar in the year ………………….
a) 1762
b) 1764
c) 1766
d) 1768
Answer:
b) 1764

10. Which Europeans came first to India as traders?
a) The French
b) The British
c) The Portuguese
d) The Dutch
Answer:
c) The Portuguese

II. Fill in the blanks:
1. The place where document are presented in ……………….. .
Answer:
Archives

2. …………… was a Translator in Pondicherry to assist French trade in India.
Answer:
Ananda Rangam

3. Ananda Rangam diaries contain the Indo ……………….. relationship.
Ans: French

4. ………………… is one of the largest archives in Asia.
Answer:
NAI, New Delhi

5. …………….. is one of the oldest and largest document repositories in Southern India.
Answer:
Tamil Nadu Archives

6. ………………. called is the Father of National Archives of India.
Answer:
George William Forest

7. Tamil Nadu Archives knew as …………….
Answer:
The Madras Record Office

8. ……………… issued the first calendar of Madras record in 1917.
Answer:
Dodwell f

9. In 1696, Port St. David was built by the ……………… in Cuddalore
Ans: British

10. The Reserve bank of India was setup in ……………….
Answer:
1935

11. The first coinage in modem India was issued in 1862 by ………………. .
Answer:
British

12. In the year ……………… Portuguese claimed the naval supremacy in Asia.
Answer:
1509

13. …………. maintained friendly relations with the Vijayanagar Empire.
Answer:
Alfonso de Albuquerque

14. Vasco da Gama was cordially received by ……………….
Answer:
King Zamorin

15. ……………… Was the first capital of the Portuguese East India company
Answer:
Cochin

III. Match the following.

1. St. Francis Church	a) Madras
2. St. Louis Fort	b) Cuddalore
3. St. George Fort	c) Cochin
4. St. David Fort	d) New Delhi
5. India Gate	e) Pondicherry

Answer:

1. St. Francis Church	c) Cochin
2. St. Louis Fort	e) Pondicherry
3. St. George Fort	a) Madras
4. St. David Fort	b) Cuddalore
5. India Gate	d) New Delhi

IV. State true or false.
1. Vasco da Gama came to India for the second time in 1501 with 20 ships
Answer:
False

2. King Zamorin defeated by the Portuguese.
Answer:
True

3. The wealth of India attracted Americans by the accounts of foreign writers.
Answer:
False

4. Albuquerque maintained friendly relations with the Vijayanagar Empire.
Answer:
False

5. The Catholic religion spread in certain regions in India’s western and eastern coasts.
Answer:
True

V. Consider the following statements and tick(✓) the appropriate answer:
1. The real founder of the Portuguese power in India was Alfonsa de Albuquerque.
2. He captured Goa from the sultan of Bijapur in November 1570.
3. In 1575, he established the Portuguese authority Ormuz in the Persian Gulf.
4. Alfonso de Albuquerque encouraged the marriages of the Portuguese with Indian women.
a) all are correct
b) all are incorrect
c) 3 is correct
d) 2 is incorrect
Answer:
a) all are correct

2. Find out the wrong pair:
1. Zamorin – Calicut
2. Bahadur shah – Gujarat
3. Shaistakhan – Governor of Chennai
4. Sher khan Lodi – Bijapur
Answer:
3. Shaista khan – Governor of Chennai

VI. Answer the following in one or two sentences.
1. What are written sources?
Answer:
Written sources include literature Travel accounts, Diaries, Auto Biographies, pamphlets, Government Documents, and Manuscripts.

2. What is Bluewater policy?
Answer:

• In 1905, Francisco de Almeida was sent as the first Governor for the Portuguese possessions in India.
• His policy was known as the ” Bluewater policy”
• Almeida had the aim of developing the naval Portuguese in India.

3. What are the factors of the comparative success of the British in India?
Answer:
The comparative success of the British over the Portuguese, the Dutch, the Danish, and the French was Largely due to their commercial competitiveness, Spirit of supreme sacrifice, government support, naval superiority, national character and their ascendency in Europe.

VII. Answer the following:
1. Give an account of the Tamil Nadu Archives.
Answer:

• The Madras Record Office which is presently known as Tamil Nadu Archives (TNA) is located in Chennai. It is one of the oldest and the largest document repositories in southern India. Most of the records are in English. Few documents are in French, Portuguese, Tamil, and Urdu.
• Tamil Nadu Archives has 1642 volumes of Dutch records which relate to the Cochin and Coromandal coast. These records cover the period from 1657-1845. The Danian records cover the periods from 1777-1845.
• Dodwell prepared with great effort and issued the first calendar of Madras records which was published in 1917. He was highly interested in encouraging historical researches. He opened a new chapter in the history of Tamil Nadu Archives.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf Geography Chapter 8 Map Reading Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions Geography Chapter 8 Map Reading

Samacheer Kalvi 8th Social Science Map Reading Text Book Back Questions and Answers

I. Choose the best answer.
1. The subject which deals with map making process is ……………….. .
a) Demography
b) Cartography
c) Physiography
d) Topography
Answer:
b) Cartography

2. A map that shows the physical features of an area is called ………………. .
a) Cadastral map
b) Relief map
c) Climatic map
d) Resource map
Answer:
a) Cadastral map

3. Shallow water bodies are represented by ……………. colour
a) Yellow
b) Brown
c) Light blue
d) Dark blue
Answer:
c) Light blue

4. The maps which are known as plans are
a) Cadastral maps
b) Topographical maps
c) Isoline maps
d) Transport maps
Answer:
a) Cadastral maps

5. Actual distribution of population can be represented by …………….. .
a) lines
b) Shades
c) Dots
d) Contours
Answer:
b) Shades

II. Fill in blanks.
1. The globe is the true representation of the ……………… .
Answer:
Earth

2. A way of representing the spherical earth on a flat surface is …………….. .
Answer:
Map

3. A line that joins the points of equal elevation is ……………. .
Answer:
Isolines

4. Cadastral maps are usually maintained by…………….. .
Answer:
Thematic map

5. …………… map is focused on a specific theme.
Answer:
Local administrator

III. Choose the option which matches the following correctly.
1. Legend – 45°
2. North East – brown colour
3. Contour Line – thematic map
4. Cadastral map – key of a map
5. Choropleth – taxation
a) 3,5,1,4,2
b) 4,1,2,5,3
c) 2,5,1,3,4
d) 5,2,4,1,3
Answer:
c) 2,5,1,3,4

IV. Match the statement with the reason and select the correct answer.
1. Statement : Small scale maps can show only major features.
Reason : Due to lack of space ,it shows large areas like Continents and countries,
a) Statement is true but reason is wrong.
b) Statement is wrong and reason is correct,
c) Both the statement and reasons are correct
d) Both the statement and reasons are wrong.
Answer:
c) Both the statement and reasons are correct

2. Statement : The conventional signs and symbols are the keys of map reading.
Reason : These symbols give a lots of information in a limited area.
a) Both the statement and reasons are correct.
b) Statement is wrong and reason is correct.
c) Statement is true but reason is wrong.
d) Both the statement and reasons are wrong.
Answer:
a) Both the statement and reasons are correct

V. Answer the following in a sentence or two.
1. Define “Map scale”.
Answer:

1. Map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground.
2. The map scale is stated in words i.e., 1 cm to 1 km.

2. What is a physical map?
Answer:
Map which shows the physical feature of an area is called a physical map.

3. Write a short note on map projection.
Answer:A map projection is a way of representing the spherical earth on a flat surface of a map. The curved surface of the earth cannot be shown accurately on a map. So, cartographers use map projections while mapping the earth surface which would help them to reduce distortions.

4. Name the Intermediate directions.
Answer:
The intermediate directions are northeast, north west, south east, and south west.

5. What are the uses of a cadastral map?
Answer:
Cadastral maps are useful for local administration such as the city survey, taxation, management of estates and to define property in legal documents.

VI. Differentiate.
1. Relief map and thematic map.

Relief Map	Thematic Map
Map that shows the physical features of an area is Usually called Relief map.	Map that focuses on a specific them or subject area.
It shows landforms like rivers, mountains.	It shows phenomena like temperature variation, rainfall distribution and population density.

2. Large scale map and small scale map.

Large scale Map	Small Scale Map
Large scale maps portray the information in detail than the small scale maps.	Small scale maps shows only major feature omitting the minor ones due to lack of space. Large areas like continents or countries small scale maps are used.

3. Globe and Map.

Globe	Map
Globe gives a three-dimensional representation of the entire world and it is a miniature form of the earth.	Map gives a two-dimensional representation of certain regions or the entire world.

VII. Answer in a paragraph.
1. Explain the different types of scales in detail.
Answer:
Scales on maps can be represented in three different ways. They are:

1. Statement or Verbal scale
2. Representative Fraction (RF) or Ratio Scale
3. Graphical or Bar Scale

1. Statement or Verbal scale:

• In this method, the map scale is stated in words i.e., 1 cm to 1 km.
• It means 1 cm distance on the map corresponds to 1 km distance on the ground.
• Thus it is written on the map like 1 cm to 1 km.

2. Representative Fraction (RF) or Numerical Fraction or Ratio Scale:

• It shows the relationship between the map distance and the corresponding ground distance in the same units of length.
• R.F. is generally shown as a fraction.

3. Graphical or Bar Scale or Linear Scale:

• A graphic scale looks like a small ruler drawn at the bottom of the page.
• This line is divided and sub-divided into lengths each of which represents a certain distance on the ground.
• This scale has an added advantage for taking copies of maps as the measurement does not change.

2. Describe the Cadastral map and its importance.
Answer:

• The Cadastral map refers to a map which shows the boundaries and ownership of land within a specified area.
• They are sometimes called plans.
• They show full details of boundaries and buildings.
• They are useful for local administration such as city survey, taxation to define property in legal documents.
• It is maintained by the government as a public record.

Importance:

• It surveys documents boundaries of land ownership, diagrams, sketches plan, and maps.
• They are originally used to ensure reliable facts for land valuation and taxation.

3. Write a paragraph about the conventional signs and symbols.
Answer:
The conventional signs and symbols:

1. Conventional signs are symbols used in maps to represent different features.
2. The symbols are explained in the key of the map.
3. These symbols give a lot of information in a limited space.
4. With the use of these symbols, maps can be drawn easily and the concept of the map can be understood well. There is an international agreement regarding the use of certain symbols.
5. The symbols that fall under this category are Called Conventional Symbols. Another category is called contextual symbols which are decided by the cartographers.

Samacheer Kalvi 8th Social Science Map Reading Additional Important Questions and Answers

I. Choose the Correct answer.
1. A choropleth map is a ………………… Map.
a) Physical
b) Thematic
c) Cadastral
d) All of these
Answer:
b) Thematic

2. Each dot on a dot – density map represents some amount of …………………
a) data
b) water
c) equal
d) All of these
Answer:
a) data

3. Cadastral is derived from ………………… word.
a) french
b) Latin
c) greek
d) English
Answer:
a) french

4. The ………………… surface of the earth cannot be shown accurately on a map.
a) flat
b) curved
c) spherical
d) None of the above
Answer:
b) curved

5. Latitudes and longitudes marked on the map give the ………………… information of the area.
a) Locational
b) Physical
c) Thematical
d) Directional
Answer:
a) Location

6. The ………………… cannot draw maps the same size as the land.
a) Demography
b) Cartography
c) Physiography
d) Topography
Answer:
b) Cartography

7. A ………………… looks like a small ruler drawn at the bottom of the page.
a) Verbal scale
b) Bar scale
c) Legend
d) Direction
Answer:
b) Bar scale

8. A ………………… is included in a map to unlock it.
a) Verbal scale
b) Bar scale
c) Legend
d) Direction
Answer:
c) Legend

9. ………………… is of done by means of an arrow pointing to the north
a) Verbal scale
b) Bar scale
c) Legend
d) Direction
Answer:
d) Direction

10. The ………………… should normally be given outside the frame of the map.
a) Source
b) Bar scale
c) Legend
d) Direction
Answer:
a) Source

II. Fill in the blanks.
1. Each map has its own ………………… which is indicated on the map.
Answer:
Scale

2. ………………… tells about the content of the map.
Answer:
Title

3. ………………… shows the relationship between the map distance and the corresponding ground distance.
Answer:
Representative fraction

4. A ………………… looks like a small ruler drawn at the bottom of the page.
Answer:
graphic scale

5. Directions on a map are often given with a symbol called ………………….
Answer:
a Compass rose

6. Maps and globe an important tools for …………………
Answer:
Geographers

7. ………………… is an act of interpreting or understanding the geographic information portrayed on a map.
Answer:
Map reading

8. Globe gives a dimensional Representation of the entire world.
Ans: three

9. ………………… and ………………… marked on maps give the locational information of the area covered in the respective maps.
Answer:
Latitudes, Longitudes

10. ………………… give a lot of information in a limited space.
Answer:
Conventional signs

11. The meaning cadastral, is ………………….
Answer:
Register of Territorial Property

12. ………………… are classified into qualitative and quantitative thematic maps.
Answer:
Thematic maps

13. ………………… is an act of interpreting the geographic information Portuguese on a map
Answer:
Map Reading

14. In the represents ………………… distance
Answer:
1 km

15. In the map Legend symbol denotes …………………
Answer:
camp

III. Choose the option which matches the following correctly.

1. Map	a) Lines connect the same value
2. Cartography	b) Register of Territorial property
3. Map scale	c) Mapmaking
4. Cadastre	d) two-dimensional representation
5. Isoline	e) relationship between distance

Answer:

1. Map	a) Lines connect the same value
2. Cartography	b) Register of Territorial property
3. Map scale	c) Mapmaking
4. Cadastre	d) two-dimensional representation
5. Isoline	e) relationship between distance

IV. Match the statement with the reason and select the correct answer.
1. Statement: A map projection is a way of representing the spherical earth on a flat surface of a map.
Reason: The curved surface of the earth cannot be shown accurately on a map.
a) Statement is true but the reason is wrong.
b) Statement is wrong and the reason is correct,
c) Both the statement and reasons are correct.
d) Both the statement and reasons are wrong.
Answer:
c) Both the statement and reasons are correct

2. Statement: map key or legend is included in a map to unlock it.
Reason: It gives you the information needed for the map to make sense.
a) Statement is true but the reason is wrong.
b) Statement is wrong and the reason is correct.
c) Both the statement and reasons are correct.
d) Both the statement and reasons are wrong.
Answer:
c) Both the statement and reasons are correct

V. Answer the following in a sentence or two.
1. Why Is cadastral important?
Answer:
Codastral map survey documents the boundaries of land ownership, by the production of document diagram, sketches, plans, charts, and maps.

2. What are two kinds of Thematic maps?
Answer:
A thematic map is classified into qualitative and quantitative thematic maps.

3. What is a Qualitative map?
Answer:
A qualitative map is in the form of quality and expresses the presence or absence of the subject on a map like the kind of vegetation.

4. What are Isobars?
Answer:
Isobars shows the distribution of atmospheric pressure and isotherms showing the distribution of temperature.

5. State any two uses of maps.

• To find the location of objects and places.
• Display weather conditions.

VI. Differentiate.
1. Conventional signs and Symbols.

Conventional signs	Symbols
Conventional signs are symbols used in maps to represent different features.	The symbols are explained in the key of the map. These symbols give a lot of information in a limited space.

2. Cadastral Map and Thematic Map.

Cadastral Map	Thematic Map
A cadastral map refers to a map that shows the boundaries and ownership of land within a specified area. These maps are sometimes known as plans.	A thematic map is a map that focuses on a specific theme or subject area such as physical phenomena like temperature variation, rainfall distribution and population density in an area.
As they are on large scale, they show full details of the boundaries and buildings.	Thematic maps emphasize spatial variation of human issues like population density or prevalence of diseases.

VII. Answer in a paragraph.
1. What are the uses of maps?
Answer:

• To find location of objects and places.
• To find the transportation routes.
• Maps show strategic location is useful for the military.
• Serve as a tourist guide.
• To find the spatial distribution of different phenomena.
• Display weather conditions.
• Highly helpful in learning geography.
• Represent the real world on small scale.

2. What are the basic components of a map? Explain any two.
Answer:
The basic components of a map are

• Title
• Scale
• Legend or key
• Direction
• Source
• Map projection and locational information and
• Conventional signs and symbols.

Title:
The title tells about the content of the map and is placed mostly at the top comer or at the bottom comer of the map.

Legend or key:

• A map key or Legend is included to unlock the map.
• It gives us the needed information.
• Maps often use symbols or colours to represent things and the key explains what they mean.
• Symbols are the key might be pictures or icons that represent different things on the map.
• Some examples are map legend.
• Campground.
• Emergency Telephone.
• Gravel Road.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf Geography Chapter 7 Exploring Continents Africa, Australia and Antarctica Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions Geography Chapter 7 Exploring Continents Africa, Australia and Antarctica

Samacheer Kalvi 8th Social Science Exploring Continents Africa, Australia and Antarctica Text Book Back Questions and Answers

I. Choose the correct answer.
1. The southernmost tip of Africa is.
a) Cape Blanca
b) Cape Agulhas
c) Cape of Good Hope
d) Cape Town
Answer:
c) Cape of Good Hope

2. The manmade canal through an isthmus between Egypt and Sinai Peninsula is
a) Panama Canal
b) Aswan Canal
c) Suez Canal
d) Albert Canel
Answer:
c) Suez Canal

3. In respect of the Mediterranean climate, consider the following statements, and choose the correct answer.
(1) The average rainfall is 15cm
(2) The summers are hot and dry, winters are rainy.
(3) Winters are cool and dry, Summers are hot and wet
(4) Citrus fruits are grown
a) 1 is correct
b) 2 and 4 are correct
c) 3 and 4 are correct
d) All are correct
Answer:
b) 2 and 4 are correct

4. The range which separates the west and east flowing rivers in Australia is
a) Great Dividing Range
b) Himalayan Range
c) Flinders range
d) Mac Donnell Range
Answer:
a) Great Dividing Range

5. Kalgoorile is famous for ………. mining.
a) Diamond
b) Platinum
c) Silver
d) Gold
Answer:
d) Gold

II. Fill in the blanks.
1. Atlas Mountain is located in ………………. continent
Answer:
African

2. ………………. is the highest peak of Africa.
Answer:
Mt. Kilimanjaro

3. ………………. is the most common tree in Australia.
Answer:
Eucalyptus

4. A temperate grass land of Australia is called ………………. .
Answer:
Downs

5. ………………. is the first Indian research station in Antarctica.
Answer:
Dakshi Gangotri

III. Match the following.

1. Pinnacle	a) Equatorial forest.
2. Krill	b) salt lake
3. Ostrich	c) small red fish
4. Lake Eyre	d) flightless bird
5. Jewel of the Earth	e) Pointed limestone pillar

Answer:

1. Pinnacle	e) Pointed limestone pillar
2. Krill	c) small red fish ‘
3. Ostrich	d) flightless bird
4. Lake Eyre	b) salt lake
5. Jewel of the Earth	a) Equatorial forest

IV. Let us learn.
1. Assertion (A) : Aurora is a curtain of colour lights appear in the sky.
Reason (R) : They are caused by magnetic storms in the upper atmosphere.
a) Both A and R are individually true and R is the correct explanation of A.
b) Both A and R are individually true but R is not the correct explanation for A.
c) A is true but R is false.
d) R is true but A is false
Answer:
a) Both A and R are individually true and R is the correct explanation of A.

2. Assertion (A) : A geological feature of Africa is the Great Rift Valley.
Reason (R) : A Rift valley is a large crack in the earth’s surface formed by tectonic activity.
a) Both A and R is individually true and R is the correct explanation for A.
b) Both A and R are individually true but R is not the correct explanation for A.
c) A is true but R is false.
d) R is true but, A is false.
Answer:
a) Both A and R is individually true and R is the correct explanation for A

V. Answer in brief.
1. Why Africa is called a “Mother Continent”?
Answer:
Africa is nicknamed the ‘Mother Continent’ as it was the oldest inhabited continent on Earth.

2. What are the important rivers of Africa?
Answer:
The most important rivers in Africa

• River Nile – father of African rivers.
• River Congo or Zaire – the second largest river.
• River Niger – Major river.
• River Zambezi – fourth largest river and River of life.

3. Name the physical division of Australia.
Answer:
The Physical divisions of Australia are –

1. The Great Western Plateau
2. The Central Low lands
3. The Eastern High lands

4. Write about the nature of the Antarctic continent.
Answer:

• Antarctica is the southernmost and fifth-largest continent in the world.
• As it is located in polar regions it is the coldest continent with a permanent cover of ice.
• Its landform consists of mountains, peaks, valleys, glaciers, and plateau.

5. Mention any four economic activities of Australia.
Answer:
Agriculture, forestry, fishing mining, manufacturing, trade, and services are the major economic activities of Australia.

VI. Distinguish between.
1. Sahel and Sahara

Sahel	Sahara
Sahel means border or margin	Largest hot desert in the world.
It is largely a semi – acid belt of barren, sandy and rocky land.	It covers the area of 11 countries.
This region marks the physical and cultural transition.	Mt. Koussi, an extinct volcano in chad is the highest point in Sahara.

2. Western Antarctica and Eastern Antarctica.

Western Antarctica	Eastern Antarctica
Faces the Pacific Ocean.	Faces the Atlantic and Indian Ocean.
Antarctica Penninsula which points towards South America shows that it is the continuation of the Andes mountain range.	Mt. Erebus is an active volcano. Located in Ross Island. Onlycontinent called white continent because of the ice cap in 4,000 meters deep.

3. Great Barrier Reef and the Artesian Basin.

Barrier Reef	Artesian Basin
1. It is located in the northeast of Australia along the east coast of Queensland in the Pacific Ocean.	The Artesian Basin is a region on the earth’s surface where water gushes out like a fountain.
2. It is formed by the tiny coral polyps.	Largest and deepest basin in the world.
3. It is about 2300 km long.	Located in the west of the Great Dividing range.
4. One of the natural wonders of the world.	Found in arid and Semi-arid parts of Queensland.

VII. Give reasons.
1. Egypt is called the gift of the Nile.
Answer:

• The Nile is the lifeline of Egypt
• Without the Nile, Egypt would have been a desert
• So Egypt in the gift of the Nile.

2. Deserts are found in the western margins of the continents.
Answer:

• Most deserts are found in the Western margins of the subtropics.
• Because the prevailing winds in the tropics are tropical easterly winds.
• The tropical easterly winds become dry by the time they reach the western margins.

3. Antarctica is called the continent of scientists.
Answer:

• Scientists of any country are free to conduct experiments and collect data from Antarctica.
• Hence it is called the ‘continent of Science’.

VIII. Answer in a paragraph each.
1. Give an account of the mineral wealth of Australia.
Answer:

• Minerals are the largest export item in Australia.
• It contributes about 10 % of the country’s GDP.
• Australia is the world’s leading producer of bauxite, limonite, the second-largest producer of gold. lead, lithium, manganese ore, and zinc.
• The third-largest producer of iron ore and uranium and the fourth-largest producer of black coal.
• The Coal belts of the country stretch from New castle to Sydney.
• Iron ores are found mainly in southern and Western Australia.
• Bauxite is mined around the Gulf of Carpentaria.
• Uranium is mined in northern territory.
• Gold is mined in the Western desert at Kalgoorlie and Coolgardie.

2. Describe the flora and fauna of Antarctica.
Answer:
Flaora and Fauna:

1. Since the temperature is below freezing point almost throughout the year, no major vegetation is found in this continent.
2. Simple plants like algae, mosses, liverworts, lichens, and microscopic fungi can survive and grow in Antarctica.
3. Some algae live in the snow, while other plants grow on the coastal rocky land that is ice-free.
4. A few species of plants, such as plankton, algae, and mosses are seen in and around, Antarctica’s fresh and saltwater lakes.
5. Small redfish called krill are found in large shoals. It is food for many warm-blooded sea animals.
6. The blue whale is the largest animal that feeds on plankton. All these animals and birds have a thick layer of fat called blubber which helps them to withstand the cold condition.
7. Penguin birds in Antarctica cannot fly. They have webbed feet and flippers instead of wings. Small invertebrates are the only land animals which live in the continent.

3. Name the physical divisions of Africa and explain anyone.
Answer:
The physical divisions of Africa are

1. Sahara
2. Sahel
3. Savanna
4. The Great Rift Valley and the Great Lakes of Africa
5. East Africa Highlands
6. Swahili Coast
7. The Congo Basin or Zaire Basin
8. Southern Africa.

Sahel:

• Sahel means border or margin. Sahel is a semi-arid tropical Savannah region that lies between Sahara.
• Desert in the north and grassland into the south.
• It Stretches east-west for a distance of 4000 km and covers an area of 30 million sq Km.
• It is largely a semi-arid belt of barren, sandy, and rocky land.
• This region marks the physical and cultural transition between the more fertile tropical regions in the south and desert in the north.

X. Activity.
1. Find out the hemisphere and season during December for the following countries

Country	Hemisphere	Season
South Africa	Southern	Summer
Morocco	Northern	Winter
Australia	Southern	Summer
Niger	Northern	Winter
Egypt’	Northern	Winter
Tasmania	Southern	Summer
India	Northern	Winter

Samacheer Kalvi 8th Social Science Exploring Continents Africa, Australia and Antarctica Additional Important Questions and Answers

I. Choose the correct answer.
1. Jasmania is also known as
a) Apple Island
b) Bourke
c) Artesion Basin
d) Sydney
Answer:
a) Apple Island

2. …………….. was discovered by Captian James Cook in 1770
a) Canberra
b) Australia
c) Africa
d) Antarctica
Answer:
b) Australia

3. Tropical rain forest is called the
a) Tropical deserts
b) Jewel of the earth
c) Mother continent
d) Rift Valley
Answer:
b) Jewel of the earth

4. Lake is the largest freshwater body in Africa.
a) Supervisor
b) Victoria
c) Albert
d) Kiva
Answer:
b) Victoria

5. Mount an extinct volcano in chad is the highest point in the Sahara
a) Koussi
b) Kilimanjaro
c) Everest
d) Atlas
Answer:
a) Koussi

6. …………………. is nicknamed the ”mother continent”.
a) Africa
b) Australia
c) South Africa
d) None of these
Answer:
a) Africa

7. the Maghreb means west in language.
a) greek
b) Sanskrit
c) Arabic
d) None of these
Answer:
c) Arabic

8. …………….. is one of the largest hot deserts in the world.
a) Sahara
b) Sahel
c) Savanna
d) Great Rift Valley
Answer:
a) Sahara

9. …………….. flows through West-Central Africa and drains into the Atlantic Ocean.
a) River Nile
b) River Congo
c) River Niger
d) River
Answer:
b) River Congo

10. The Tropic of Capricorn cuts the continent almost into equal halves.
a) three
b) three
c) four
d) two
Answer:
d) two

II. Fill in the blanks.
1. …………… is the largest research station on Antarctica.
Answer:
Mcmurdo

2. Vinson. …………….. is the highest peak in Antarctica.
Answer:
Massif

3. Wool is described as ……………. of Australia.
Answer:
Cash Crop

4. …………… is the longest river in Australia.
Answer:
River Murray

5. Great Barrier Reef is formed by …………………
Answer:
Coral Polyps

6. Sahel means ………………..
Answer:
border or margin

7. …………… is the capital of ghana.
Answer:
Acera

8. …………… was the first to use the term “Dark Continent”.
Answer:
Henry M. Stanly

9. ………….. is the deepest point in Sahara.
Answer:
The Qattara Depression

10. …………… is the highest point in Atlas Mountain.
Answer:
Mount Jaubbakal

11. ………….. is one of the largest plains in Savanna.
Answer:
The Serengeti Plain

12. People of Swahili culture is called ……………….
Answer:
Swahili

13. ………………… Mountain is found in the eastern portion of the escarpment.
Answer:
Drakensberg

14. Nile river is also called ………………
Answer:
Father of African river

15. The country Egypt is called ………………….
Answer:
gift of the Nile

III. Match the following.

1. Bamboo tree	a) Veld
2. Karoo	b) Libya
3. Open air Zoo	c) Africa
4. A1 – ziza	d) Sheep rearing
5. Grassland	e) Savanna

Answer:

1. Bamboo tree	c) Africa
2. Karoo	d) Sheep rearing
3. Open air Zoo	e) Savanna
4. A1 – ziza	b) Libya
5. Grassland	a) Veld

IV. Let us learn.
1. Assertion (A): Antarctica is a unique continent but it does not have a native population. There is no country in Antarctica.
Reason (R): It is located in the polar region, it is the coldest continent with a permanent cover of ice.
a) Both A and R are individually true and R is the correct explanation for A.
b) Both A and R are individually true but R is not the correct explanation for A.
c) A is true but R is false.
d) R is true but A is false.
Answer:
a) Both A and R are individually true and R is the correct explanation for A.

2. Assertion (A): A rift valley is a large crack in the earth’s surface formed by the shifting of tectonic plates.
Reason (R): It runs through eastern Africa and contains many lakes.
a) Both A and R are individually true and R is the correct explanation for A.
b) Both A and R are individually true but R is not the correct explanation for A.
c) A is true but R is false.
d) R is true but A is false.
Answer:
a) Both A and R are individually true and R is the correct explanation for A.

V. Answer in brief.
1. Write a short note on Xerophytes.
Answer:
The Plants and trees in Australia are adapted to dry conditions and can survive for long period without water called Xerophytes.

2. What is the Political division of Australia?
Answer:

• The political division of Australia are six states and two union territories.
• They are New South Wales, Queensland, South Australia, Jasmania, Victoria, Western Australia, Northern Territory, and Capital Territory.

3. What do you know about the “Continent of Science”?
Answer:
Scientists of any Country are free to conduct experiments and collect data from Antarctica and so it is called the continent of science.

4. Great Barrier Reef – Explain
Answer:

• Great Barrier Reef is located in the northeast of Australia along the east coast of Queen’s land in the Pacific Ocean.
• It is formed by the tiny coral polyps.

5. State a few minerals found in Antarctica.
Answer:
Few minerals found in Antarctica are gold, Platinium, Nickel, Copper, and petroleum.

VI. Distinguish between.
1. The Great Western Plateau and The eastern highlands.

The Great Western Plateau (Australia)	The eastern highlands
1. It is Australia’s largest physical division. Its area is about 2,700,000 square kilometers.	It extends for about 3860 km along the eastern edge of Australia.
2. It is 863 meters high above sea level. It is one of the natural wonders of Australia.	Australian Alps mountain range is the highest mountain range in Australia. It is covered with ice.
3. The Great Victoria Desert is the largest desert in Australia located in Western, Australia, and South Australia.	The highest peak of this range is Mt. Kosciuszko (2230 m) and is located in New South Wales.

2. River Nile and River Congo or Zaire.

River Nile	River Congo or Zaire
The Nile is the longest river in the world. The Nile is known as the “Father of African Rivers”.	Congo is the second largest river in Africa after the Nile.
Its length is about 6650 km.	Its length is about 4700km.
It flows northward and drains into the Mediterranean-sea.	It flows through West-Central Africa and drains into the Atlantic Ocean.

VII. Give reasons.
1. The Zambezi River is a Southern African “River of Life.
Answer:

• The fourth-largest river system in Africa.
  It drains seven countries and supports millions of people, who make use of its rich fisheries, forests, water, and rich floodplain soils.

2. the Nile is known as the “Father of African Rivers”.

• Nile River the longest river in the world, called the father of African rivers.
• It rises south of the Equator and flows northward through northeastern Africa to drain into the Mediterranean Sea.
• It has a length of about 6,650 kilometers and drains an area estimated at 3,349,000 square kilometers.

1. How is the climatic condition of Africa divided?
Answer:
It is divided into six major climatic zones. They are.
Arid and semi-arid climate:

• Northern & Southern Africa
• Rainfall – scanty Tropical Savanna Climate:
• 100-200 latitude or either side of the equator
• The tropical wet and dry climate
• Equatorial climate
• The equatorial region near the congo basin and east African highlands.
• Temperature and rainfall are high.

Temperature Climate:

• The southern tip of southern Africa.
• Climate Equable
• Mediterranean Climate
• NorthWestern and Southwestern tip of Africa.
• Gets rainfall in winter while in summer it is hot and dry.

Tropical Monsoon Climate:

• Eastern shore of Africa.
• Summer is hot with monsoon winds bringing good rainfall winter is cool and dry.

2. What’s the role of agriculture in Africa?
Answer:

• Agriculture is a major economic activity.
• Wheat is grown in temperate grasslands.
• Rice is cultivated on the Guinea coast.
• Maize and Millets are grown all over the plateau.
• Cotton is the chief cash crop of Africa.
• Coffee is grown in Ethiopia
• Ghana is the chief producer of cocoa.
• Oil palm in west African countries.
• Sugarcane, rubber, tobacco are the major crops of East African countries.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf Geography Chapter 6 Industries Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions Geography Chapter 6 Industries

Samacheer Kalvi 8th Social Science Industries Text Book Back Questions and Answers

I. Choose the correct answer.
1. Silk weaving and household industries come under the category of ………………….
a) Small scale industry
b) Large scale industry
c) Marine based industry
d) Capital intensive industry
Answer:
a) Small scale industry

2. On the basis of ownership the industry can be divided into ……………… types
a) 2
b) 3
c) 4
d) 5
Answer:
c) 4

3. Amul dairy industry is the best example of ……………….. sector.
a) Private
b) Public
c) Co-operative sector
d) Joint sector
Answer:
c) Co-operative sector

4. Iron and Steel and Cement Industries are examples of ………………….. industries.
a) Agro-based
b) Mineral-based
c) Forest-based
d) Marine based
Answer:
b) Mineral-based

5. Tertiary activity is divided into ……………….. types
a) 4
b) 3
c) 2
d) 5
Answer:
c) 2

II. Fill in the blank.
1. Banking is a ……………. economic activity.
Answer:
Tertiary

2. Tertiary activity is divided into ……………. and ……………..
Answer:
Quaternary, Quinary

3. Government decision-making process comes under the ……………… category of tertiary economic activity.
Answer:
Quinary

4. Raw material based perspective Cotton Textile industry is a ………………. industry.
Answer:
Agro-based

5. Capital required for establishing a large scale industry is more than ………………..
Answer:
One Crore

III. Match the following.

1. Judicial sector	a) Private Sector
2. TV telecasts	b) Non Geographical factor
3. Geographical factor	c) Quaternary activity
4. Capital	d) Raw materials
5. BajajiAuto	e) Quinary activity

Answer:

1. Judicial sector	e) Quinary activity
2. TV telecasts	c) Quaternary activity
3. Geographical factor	d) Raw materials
4. Capital	b) Non Geographical factor
5. Bajaj Auto	a) Private Sector

IV. Distinguish the following.
1. Secondary economic activity and tertiary economic activity.

Secondary economic activity	Tertiary economic Activity
It changes raw materials into usable products through processing and manufacturing	It provided essential services and support industries to function.
Eg: Bakery	Eg: Education

2. Agro-based and marine-based industries.

Agro-based industry	Marine based industry
Industries which use plant and animal-based products as raw materials.	Industries which use products from the sea and oceans as raw materials.
Eg: Cotton textile	Eg: Seafood processing

3. Large scale industries and small scale industries.

Large Scale Industries	Small Scale Industries
The Capital required for the establishment of an industry is more than one crore	The Capital required for the establishment of an industry is less than one crore
Eg: Iron and Steel	Eg: Silk wearing

V. Answer briefly.
1. Define the industry.
Answer:
The industry is a process by which the raw materials are changed into finished products.

2. What is meant by economic activity?
Answer:
Any action that involves the production, distribution, consumption, or service is an economic activity.

3. Name the major economic activities.
Answer:
The major economic activities are:

• Primary Economic Activities (e.g., Raw cotton production)
• Secondary Economic Activities (e.g., Spinning mill)
• Tertiary Economic Activities (e.g., Trade, Transport)

4. What are the secondary economic activities? Give some examples.
Answer:
The activity which changes raw materials into usable products through processing and manufacturing
eg: Bakery, factory.

5. What is the Quinary activity? Elucidate with an example.
Answer:

1. Quinary economic activities refer to the high-level decision making processes by executives in industries, business, education, and government.
2. This sector includes top executives or officials in the fields of science and technology, universities health care, etc.
3. In our house, our parents make decisions by themselves in some situations.
4. Similarly, the Council of Ministers takes decisions to introduce various people welfare schemes in the state.
5. These two are examples of quinary activities.

6. Name the factors responsible for the location of industries.
Answer:
Raw material, Labour, Capital, Market, Power, Land, Transport

7. Write a short note on the following
Answer:
1. Large scale Industries:
The capital required for the establishment of an industry is more than one crore the industry is called a large scale industry.
Eg: Iron & steel, Oil refineries, Cement and Textile industries, etc.

2. Small scale industries:
The capital required for the establishment of an industry is less than one crore, the industry is called a small scale industry.
Eg: Silk weaving and household industries.

VI. Write in detail.
1. Classify and explain the industries based on the source of raw materials.
Answer:
Industries are classified on various bases in the following ways. On the basis of raw materials.
1. Agro Based Industries:

• These industries use plant and animal-based products as their raw materials.
• Example; Food Processing, Vegetable Oil, Cotton Textile, Dairy Products, etc.

2. Mineral-Based Industries:

• These are the industries that use mineral ores as their raw materials.
• Iron made from iron ore is the product of a mineral-based industry. Cement, Machine Tools, etc. are the other examples of mineral-based industries.

3. Marine Based Industries:

• These industries use products from the sea and oceans as raw materials.
• Example; Processed Sea Food, Fish Oil manufacturing units, etc.

4. Forest-Based Industries:

• These industries use forest products as raw materials.
• Example; Pulp and Paper, Furniture and Some Pharmaceuticals industries, etc.

2. Explain the Geographical factors which affect the location of industries?
Answer:
The geographical factors which affect the location of industries
Raw material:
Materials cannot be transported for long distances, so industries are located near the raw material availability.

Power:
Power is the basic for the industry so it’s generated from conventional sources which should be located near the industries.

Labour:
Availability of cheap and skilled labour is more important.

Transport:
Availability of easy transportation always influences the industry location.

Storage and warehousing:
Finished products should be stored at a suitable storage or warehouse till the goods are taken to the market.

Topography:
The selected site should be flat; which is supported by different transport

Climate:

• Extreme climate condition is not suitable for successful industrial growth. Water Resources:
• Many industries are established near rivers, canals, and lakes for proper functioning.

3. Classify the industries through a flow chart.

Samacheer Kalvi 8th Social Science Industries Additional Important Questions and Answers

I. Choose the correct answer.
1. Industries are ………………. Economic Activities.
a) Primary
b) Secondary
c) Tertiary
d) Quaternary
Answer:
b) Secondary

2. …………………… is mostly generated from conventional Sources like mineral oil and water.
a) Thermal Power
b) Water Resources
c) Power
d) None of these
Answer:
c) Power

3. Service sector contributing around …………………… of the Indian Gross Domestic Product.
a) 63%
b) 53%
c) 55%
d) 73%
Answer:
b) 53%

4. …………………… is served by different modes of Transport.
a) Labour
b) Power
c) Topography
d) Climate
Answer:
c) Topography

5. The factors affecting the location of Industries are …………………….
a) Raw materials
b) Land
c) Water
d) all of these
Answer:
d) all of these

6. …………………… Sector is owned and operated by individuals.
a) Public
b) Private
c) both
d) none
Answer:
b) Private

7. Example for Mineral Based Industries is …………………….
a) Vegetable oil
b) Machine Tools
c) Cotton industry
d) None of these
Answer:
b) Machine Tools

8. Example for Forest-Based Industries is ……………………
a) Paper Industry
b) Processed Seafood
c) Cotton Industry
d) None of these
Answer:
a) Paper Industry

9. …………………… is a Private Sector Industry.
a) BHEL
b) HAC
c) SAIC
d) Reliance
Answer:
d) Reliance

10. …………………… is a Joint Sector Industry.
a) Amul
b) BHEL
c) Bajaj Auto
d) Maruti Udyog
Answer:
d) Maruti Udyog

II. Fill in blanks.
1. Many …………….. are not fit for human consumption.
Answer:
raw materials

2. The economic strength of a country is always measured by the development of ………….
Answer:
manufacturing industries

3. …………….. is one of the largest sectors of India.
Answer:
Service Sector

4. The Service sector is the …………….. of the Indian economy.
Answer:
Backbone

5. …………….. is base and essential to run the entire industry.
Answer:
Power

6. …………….. climate is ideal for the cotton textile industry.
Answer:
Cool – humid

7. …………….. is not suitable for successful industrial growth.
Answer:
Extreme Climate

8. …………….. investment is needed for the establishment of industries.
Answer:
Capital

9. Detroit city in …………….. is known as the world’s traditional automotive centre.
Answer:
Michigan in the USA

10. …………….. is known as Detroit of India.
Answer:
Chennai

11. Creation and transfer of information is …………….. activity.
Answer:
quaternary

12. …………….. is an Example of Marine Based Industries.
Answer:
Fish oil manufacturing units

13. BHEL ……………..
Answer:
Bharat Heavy Electricals Ltd

14. HAL ……………..
Answer:
Hindusthan Aeronautics Limited

15. SAIL ……………..
Answer:
Steel Authority of India

III. Match the following.

1. Primary economic activity	a) transportation
2. Secondary economic activity	b) Science and technology
3. Tertiary economic activity	c) Forestry
4. Quaternary economic activity	d) flour into bread
5. Quinary economic activity	e) television

Answer:

1. Primary economic activity	c) Forestry
2. Secondary economic activity	d) flour into bread
3. Tertiary economic activity	a) transportation
4. Quaternary economic activity	e) television
5. Quinary economic activity	b) Science and technology

IV. Distinguish the following.
1. Primary economic activity and Secondary economic activity.

Primary economic activity	Secondary economic activity
1. These are the economic activities which have been originated in the very beginning.	Secondary activities are those that change raw materials into usable products through processing and manufacturing.
2. It includes activities such as forestry, grazing, hunting, food gathering, fishing, agriculture, mining, and quarrying.	Bakeries that make flour into bread and factories that change metals and plastics into vehicles are examples of secondary activities.

2. Private Sector Industries and Public Sector Industries.

Private Sector Industries	Public Sector Industries
These types of industries are owned and operated by individuals or a group of individuals.	These types of industries are owned and operated by the Government.
Eg: Bajaj Auto, Reliance, etc.	HAL, BHEL, SAIL are examples of Public sector industries.

V. Answer briefly.
1. What is Primary economic activity?
Answer:
The activities which have been originated in the very beginning.

2. What do you know about the service sector?
Answer:
It is one of the largest sectors of India and its the backbone of the Indian economy.

3. What are the non-geographical factors responsible for the location of industries?
Answer:
Capital, Availability of Loans, Government policies or regulation.

4. How are industries classified on the basis of raw materials.
Answer:

• Agro-based industries,
• Mineral-based industries,
• Marine – based industries and
• Forest-based industries.

5. Give a short note on forest-based industries.
Answer:
The industries which use forest products as their raw materials.

6. How does climate become a factor responsible for a location for industries?
Answer:
Extreme Climatic condition is not suitable for the successful industrial growth few industries require specific climate.

7. What is co-operative sector industries.
Answer:
Industries of this kind are owned and operated by the producers or suppliers of raw materials of workers or both.

VI. Write in detail.
1. Classify and explain the industries based on the source of raw materials.
Answer:
On the basis of ownership, industries are
Private Sector Industries:

• Owned and operated by individuals or groups
• BajajAuto.

Public Sector Industries:

• Owned and operated by the Government.
• BHEL, SAIL.

Joint Sector Industries:

• Owned and operated jointly by the government and Individuals groups.
• Indian Synthetic Rubber Ltd.

Co-operative Sector Industries:

• Owned and operated by the producers.
• AMUL.

2. State the major and fundamental economic activities.
Answer:
Primary Economic Activity:

• Originated from the forest.
• Hunting, Grecizing.

Secondary Economic Activity:

• Changes raw material into usable products through processing and manufacturing.
• Bakery industries.

Tertiary Economic Activity:

• Provides essential services and support industries to function.
• Education, medical.

Quaternary Economic Activity:

• Creation and transfer of information, including research and training.
• Program telecasted in T.V.

Quinary Economic Activity:

• High-level decision-making process by executives.
• Top executives, Judiciary.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf Geography Chapter 5 v Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions Geography Chapter 5 Hazards

Samacheer Kalvi 8th Social Science Hazards Text Book Back Questions and Answers

I. Choose the correct answer.
1. ………………. percentage of nitrogen is present in the air.
a) 78.09%
b) 74.08%
c) 80.07%
d) 76.63%
Answer:
a) 78.09%

2. Tsunami in the Indian Ocean took place in the year ………………. .
a) 1990
b) 2004
c) 2005
d) 2008
Answer:
b) 2004

3. The word tsunami is derived from ………………. language.
a) Hindi
b) French
c) Japanese
d) German
Answer:
c) Japanese

4. The example of surface water is
a) Artesian well
b) Groundwater
c) Subsurface water
d) Lake
Answer:
d) Lake

5. Event that occurs due to the failure of monsoons.
a) Condensation
b) Drought
c) Evaporation
d) Precipitation
Answer:
b) Drought

II. Fill in the blanks.

1. Hazards may lead to …………….
Answer:
affect the community most severely

2. Landslide is an example of …………… hazard.
Answer:
geologic

3. On the basis of origin, the hazard can be grouped into …………… categories.
Answer:
8 (or) eight

4. Terrorism is an example of …………… hazard.
Answer:
human-induced

5. Oxides of nitrogen are …………… pollutants which affect human beings.
Answer:
primary

6. Chernobyl nuclear accident took place in
Answer:
26th April 1986

III. Match the following.

List I	List II
1. Primary pollutant	a. Terrorism
2. Hazardous waste	b. Tsunami
3. Earthquake	c. Outdated drugs
4. Meteorological drought	d. Oxides of sulphur
5. Human induced hazard	e. Reduction in rainfall

Answer:

List I	List II
1. Primary pollutant	d. Oxides of sulphur
2. Hazardous waste	c. Outdated drugs
3. Earthquake	b. Tsunami
4. Meteorological drought	e. Reduction in rainfall
5. Human induced hazard	a. Terrorism

IV. Answer in brief.
1. Define ‘hazard’?
Answer:
‘Hazards are defined as a thing, person, event or factor that poses a threat to people, structures or economic assets and which may cause a disaster.’

2. What are the major types of hazards?
Answer:

• Natural hazards
• Human-made hazards
• Socio-natural hazards

3. Write a brief note on hazardous wastes.
Answer:
The wastes that may or tend to cause adverse health effects on the ecosystem and human beings are called hazardous wastes.

4. List out the major flood-prone areas of our country.
Answer:
Punjab, West Bengal, Odisha are the region which is also prone to flood often.

5. Mention the types of drought.
Answer:
Drought could be classified into three types. They are:

1. Meteorological drought
2. Hydrological drought
3. Agricultural drought

6. Why should not we construct houses in foothill areas?
Answer:
Because of the presence of steep slopes and heavy rainfall we should not construct houses at the foothills areas.

V. Distinguish the following.
1. Hazards and disasters.

Hazards	Disasters
Hazards occur frequently and threaten people.	It is a hazardous event that occurs over a limited time span.
Ex: Natural hazards, Earthquake.	Ex: Flood

2. Natural hazards and human-made hazards.

Natural hazard	Human-made hazard
Man has no role to play in such hazards.	These are caused by the undesirable activities of humans.
Ex: Flood, drought, etc.	Ex: Pollution of air and water

3. Flood and drought.

Flood	Drought
It occurs through heavy rainfall.	It occurs through no rainfall.
It is often held in the coastal Andhra Pradesh & Odisha.	The dry region has seen in the leeward side of Western ghats.

4. Earthquake and tsunami.

Earthquake	Tsunami
The violent tremor of the earth’s crust is called an Earthquake.	Tsunami refers to huge ocean waves caused by landslides.
The study of earthquakes is called Seismograph.	The study of the Tsunami is called Oceanography.

VI. Answer in a paragraph.
1. Write an essay on air pollution.
Answer:
Pollution of Air:

1. Air is a mixture of several gases.
2. The main gases are nitrogen (78.09%) for forming products such as fertilizers for plants and for making the air inert, oxygen (20.95%) for breathing and carbon dioxide (0.03%) for photosynthesis.
3. Some other gases like argon, neon, helium, krypton, hydrogen, zenon and methane are also present.
4. Air pollution is the contamination of indoor or outdoor air by a range of gases. Air pollution can be categorized into primary and secondary pollutants.
5. A primary pollutant is an air pollutant emitted directly from a source.
6. A secondary pollutant is not directly emitted.
7. Primary pollutants are as follows:
   • Oxides of Sulphur
   • Oxides of Nitrogen
   • Oxides of Carbon
   • Particulate Matter and
   • Other primary pollutants
8. Secondary pollutants are as follows:
   • Ground Level Ozone
   • Smog

2. Define earthquake and list out its effects.
Answer:
Earthquakes:

• Earthquake is a violent tremor in the earth’s crust, sending out a series of shock waves in all directions from its place of origin.
• Earthquake-prone regions of the country have been identified on the basis of scientific inputs relating to seismicity, earthquakes that occurred in the past, and the tectonic setup of the region.
• Based on these inputs, the Bureau of Indian Standards has grouped the country into four seismic zones: Zone II, Zone III, Zone IV, and Zone V (No area of India is classified as Zone I).
  

  Seismic Zones	Level of Risk
  Zone V	Very High
  Zone IV	High
  Zone III	Moderate
  Zone II	Low

3. Give a detailed explanation of the causes of landslides.
Answer:

1. Landslide is a rapid downward movement of rock, soil, and vegetation down the slope under the influence of gravity.

2. The causes of landslides are wide-ranging, They have two aspects in common.

3. Force of gravity and

4. Failure of Soil

5. Landslides are considered of two types. They are:

• Naturally occurring disaster.
• Human-induced changes in the environment.

6. Natural causes of landslides are:

• Climatic changes
• Seismic activities
• Weathering
• Soil erosion
• Forest fires
• Gravity and
• Volcanic eruption

7. Human causes of landslides include deforestation mining, construction of roads, and railways over the mountain.

4. Elaborately discuss the effects of water pollution.
Answer:

• It may cause a harmful effect on any living thing that drinks or uses or lives in it.
• It may be defined as alternation in the physical, chemical, and biological characteristics of water, which may cause harmful effects in human and aquatic life.

The major causes of water pollution in India are:

• Urbanisation
• Industrial effluents
• Sewages etc.
• Agricultural runoff and improper agricultural practices
• Seawater intrusion
• Solid wastes

Samacheer Kalvi 8th Social Science Hazards Additional Important Questions and Answers

I. Choose the correct answer.
1. The content of Oxygen in the air is …………….
a) 20.95%
b) 21.95%
c) 22.95%
d) 23.95%
Answer:
a) 20.95%

2. The word ‘hazard’ Originated from the ……………. language.
a) French
b) Telugu
c) Malayalam
d) Kannada
Answer:
a) French

3. National Institute of Disaster Management located in ……………..
a) Britain
b) New Delhi
c) France
d) Japan
Answer:
b) New Delhi

4. In Tamil Nadu ……………. coastal districts are frequently affected by Storm Surges.
a) 13
b) 14
c) 15
d) 16
Answer:
a) 13

5. The areas that receive an annual rainfall of less than ……………. are the drought zone regions of India.
a) 60 cm
b) 50 cm
c) 40 cm
d) 45 cm
Answer:
a) 60 cm

6. The meaning of Tsunami is ……………..
a) Wave
b) Harbour wave
c) Storm
d) Storm wave
Answer:
b) Harbour wave

7. In ……………. the Ukraine part of Exclusion Zone was declared as a radiogical and environmental biosphere.
a) 2013
b) 2014
c) 2015
d)2016
Answer:
d) 2016

8. In India about ……………. of the land mass is prone to landslide hazard.
a) 15%
b) 18%
c) 19%
d) 20%
Answer:
a) 15%

9. In Trophical Cyclones the wind Speed may reach upto ……………. per hour.
a) 200 km
b) 100 km
c) 300 km
d) 400 km
Answer:
a) 200 km

10. High-Pressure Zone is mentioned in the Geographical map as ……………. letter.
a) L
b) P
c) H
d) S
Answer:
c) H

II. Fill in the blanks.
1. The meaning of hazard is ………………..
Answer:
a game of dice

2. ………………. may be worsened by the destruction of mangroves.
Answer:
Storm Surge hazard

3. ………………. is a violent tremor in the earth’s crust.
Answer:
Earthquake

4. ………………. is a strong wind circulating around a low-pressure area in the atmosphere.
Answer:
Cyclonic Storm

5. During Cyclonic the wind speed may reach upto …………. km and rainfall may record up to …………… cm.
Answer:
200, 50

6. A sudden rise of sea water due to trophical cyclone is called ………………..
Answer:
Storm Surge

7. ………………. and ………………. are the major causes of landslides.
Answer:
Steep slope, heavy rainfall

8. In Tamil Nadu ………………. and ………………. are frequently affected by landslides.
Answer:
Kodaikanal, Ooty

9. The gas used for Photosynthesis is ………………..
Answer:
Carbon dioxide

10. A ………………. pollutant is an air pollutant emitted directly from a Source.
Answer:
Primary

11. ………………. may be defined by alteration is the physical, chemical, and biological characteristics of water.
Answer:
Water Pollution

12. In India ………………. is perhaps the most critical components in Managing Disasters.
Answer:
prevention

13. Example for Biological hazard is ………………..
Answer:
Chicken Box

14. ………………., ………………. are Human-made hazards.
Answer:
Explosions, hazardous waste

15. Primary Pollutant example ………………..
Answer:
oxides of Sulphur

III. Match the following.

1. Geological hazard	a) Floods, Coastal erosion
2. Hydrologic hazard	b) Eruptions and Lava flows
3. Volcanic hazard	c) Chickenpox, Smallpox
4. Environmental hazard	d) Earthquakes, Tsunami
5. Biological hazard	e) Soil, air

Answer:

1. Geological hazard	d) Earthquakes, Tsunami
2. Hydrologic hazard	a) Floods, Coastal erosion
3. Volcanic hazard	b) Eruptions and Lava flows
4. Environmental hazard	e) Soil, air
5. Biological hazard	c) Chickenpox, Smallpox

IV. State whether the following statements are true or false.
1. Tsunami means Stormy Surge.
Answer:
False

2. A Secondary Pollutant is not directly emitted.
Answer:
True

V. Assertion and Reasons.
1. Assertion: Landslides are generally Sudden and infrequent.
Reason: The presence of Sleep Slope and heavy rainfall are the major causes of landslides.
a) A is correct but R is incorrect
b) Both A and R are incorrect
c) A is incorrect and R is correct
d) Both A and R are correct
Answer:
d) Both A and R are correct

VI. Answer in brief.
1. Define Catastrophe.
Answer:
A catastrophe is a massive disaster that requires a significant expenditure of money and a long time for recovery.

2. What are the major causes of floods?
Answer:
The major causes of floods are:
Meteorological factors

• Heavy rainfall
• Tropical cyclones
• Cloudburst Physical factors
• Large catchment area
• Inadequate drainage arrangement

Human factors

• Deforestation
• Siltation
• Faulty agricultural practices
• Faulty irrigation practices
• Collapse of dams
• Accelerated urbanisation.

3. Write short notes on Indian Ocean Tsunami?
Answer:

• On December 26, 2004, at 7:59 a.m. local time, an undersea earthquake with a magnitude of 9.1 struck off the coast of the Indonesian island of Sumatra.
• The tsunami killed at least 2,25,000 people across a dozen countries, with Indonesia, Sri Lanka, India, Thailand, Somalia and Maldives, sustaining massive damage.

4. Explain Prevention Measures.
Answer:
Prevention is defined as the activities taken to prevent a natural calamity or potential hazard from having harmful effects on either people or economic assets.

VII. Distinguish the following.
1. Geologic hazard and Environmental hazard.

Geologic hazard	Environmental hazard
Earthquakes, Tsunami, Landslide and Land subsidence.	Pollution of soil/ air/water, Desertification, Global warming and Deforestation.

VIII. Answer in a paragraph.
1. Explain about Socio – natural hazards.
Answer:
Socio-natural hazards:
These are caused by the combined effect of natural forces and misdeeds of human. Some of the examples are:

• The frequency and intensity of floods and droughts may increase due to indiscriminate felling of trees, particularly in the catchment areas of the rivers.
• Landslides are caused by natural forces and their frequency, and impact may be aggravated as a result of construction of roads, houses etc., in mountainous areas, excavating tunnels and by mining and quarrying.
• Storm surge hazards may be worsened by the destruction of mangroves.
• Smog is a serious problem in most big urban areas. The emissions from vehicles and industries, combustion of wood and coal together combined with fog leads to smog.

2. Explain the Hazards based on their origin.
Answer:
Hazards can be grouped into eight categories
1. Atmospheric hazard:
Tropical storms, Thunderstorms, Lightning, Tornadoes, Avalanches, Heat waves, Fog and Forest fire.

2. Geologic/Seismic hazard:
Earthquakes, Tsunami, Landslide and Land subsidence.

3. Hydrologic hazard:
Floods, Droughts, Coastal erosion and Storm surges.

4. Volcanic hazard:
Eruptions and Lava flows.

5. Environmental hazard:
Pollution of soil/ air/water, Desertification, Global warming and Deforestation.

6. Biological hazard:
Chickenpox, Smallpox, AIDS [HIV] and Killer bees.

7. Technological hazard:
Hazardous material incidents, Fires, Infrastructure failures [Bridges, Tunnels, Dams, Nuclear and Radiological accidents].

8. Human-induced hazard:
Terrorism, Bomb blast, War, Transportation accidents and Civil disorder.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf Geography Chapter 4 Migration and Urbanisation Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions Geography Chapter 4 Migration and Urbanisation

Samacheer Kalvi 8th Social Science Migration and Urbanisation Text Book Back Questions and Answers

I. Choose the correct answer.
1. People move from ……………. to ……………. mainly in search of better jobs.
a) Rural to Urban
b) Urban to Rural
c) Hills to plains
d) Plains to hills
Answer:
a) Rural to Urban

2. A person moves from his own country to another country is known as ……………. .
a) Immigrant
b) Refugee
c) Emigrant
d) Asylum seeker
Answer:
c) Emigrant

3. The migration in search of fertile agricultural land is ……………. migration.
a) Rural to Rural
b) Rural to Urban
c) Urban to Rural
d) Urban to Urban
Answer:
a) Rural to Rural

4. War is one of the causes of human migration.
a) Demographic
b) Socio-cultural
c) Political
d) Economic
Answer:
c) Political

5. The main reason for the development of urbanisation in the pre-historic period was
a) Production of food grains
b) Domestication of cattle
c) Fishing
d) hunting
Answer:
b) Domestication of cattle

II. Fill in the blanks:
1. Urbanisation is determined by ……………. the number of factors.
Answer:
three

2. ……………. is the major push factor operating in rural areas.
Answer:
Migration

3. ……………. Metropolitan city in India has the second-highest urban population in the world.
Answer:
Delhi

4. The movement of a person based on his free will and desire to live in a better place is called ………… migration.
Answer:
Voluntary

5. In modem time urban growth was accelerated by the development of …………….
Answer:
New trade route

III. Match the following:

1. Emigration	a) In-migration
2. Immigration	b) Outmigration
3. Pull factor	c) Unemployment
4. Push factor	d) Socio-cultural migration
5. Marriage	e) Employment opportunity

Answer:

1. Emigration	b) Outmigration
2. Immigration	a) In-migration
3. Pull factor	e) Employment opportunity
4. Push factor	c) Unemployment
5. Marriage	d) Socio-cultural migration

IV. State whether the following statements are true or false.
1. Slums are generally found in cities.
Answer:
True

2. Mass migration is absent in the modem period.
Answer:
True

3. The process of urbanisation has a short history.
Answer:
False

4. Cities and towns are the major polluters of the environment.
Answer:
True

5. Transhumance is also referred to as seasonal migration.
Answer:
True

V. Consider the given statements and choose the correct option from the given ones.
1. Statement (A): Urbanisation is mainly due to the movement of people from rural to cities.
Reason (R): Rural to urban migration is not a predominant one.
a) A is correct but R is incorrect
Both A and R are incorrect
c) Both A and R are correct
d) A is incorrect and R is correct
Answer:
c) Both A and R are correct

VI. Answer the following questions in brief:
1. Define “Migration”.
Answer:
Migration has been defined differently by different experts. In general, migration is defined as the permanent or semi permanent change of residence of an individual or group of people over a significant distance. So, the term migration refers to the movement of people from one place to another.

2. What are the causes of rural to urban migration?
Answer:
The main causes are

• Searching for jobs
• Education
• Recreation facilities.

3. State the causes of ecological or natural migration.
Answer:

1. Natural causes include volcanic eruption, mankind changed considerably.
2. At this stage, people continued to move from one region to another in search of fertile land for cultivation.

4. Name any two pull factors of migration.
Answer:

• Employment opportunities
• Education.

5. What is Urbanisation?
Answer:
Urbanization refers to the process in which there is an increase in the proportion of the population living in towns and cities.

6. List out any four most populous cities in the world.
Answer:
Tokyo, Delhi, Mexico City, Sao Paulo.

VII. Answer the following questions in detail.
1. What are the different types of migration? Explain.
Answer:
Migration can be classified in several ways. They are:
1. Based on the movement associated with administrative limits.

(a) Internal Migration
(b) International Migration

2. Based on the willingness of the migrants for migration.

(a) Voluntary Migration
(b) Involuntary Migration

3. Based on the duration of stay of migrants in the place of destination.

(a) Short term Migration
(b) Long term Migration
(c) Seasonal Migration

1. Based on the movement associated with administrative limits.
(a) Internal Migration:

1. The movement of people within a country is known as internal migration.
2. Further internal migration is classified into four types. They are,
   • Rural to Urban migration
   • Urban to Urban migration
   • Rural to Rural migration and
   • Urban to Rural migration

(b) International Migration:
Migration that occurs across the national boundaries is known as international migration.

2. Based on the Willingness of the migrants for migration:
(a) Voluntary migration:

1. If the migration takes place on perspus free will, initiative, and desire to live in a better place.

(b) Involuntary migration:

1. If the migration takes place against the will of migrants is known as involuntary migration.

3. Based on the duration of stay of migrants in the place of destination:
(a) Short term migration:

1. The migrants stay outside only for a short duration before returning to the place of origin.

(b) Long term migration:

1. The migrants stay outside at least for a few years.

(c) Seasonal migration:

1. Usually, a group of people migrates from their native places during a particular season and return after end of that season.
2. Transhumance is another example of seasonal migration.

2. Explain in detail the various causes of migration?
Answer:

• The favourable factors which attract people towards a location are called pull factors.
• The unfavourable factors which make the people move out from a location are called push factors.
• Human migration can be categorized under five groups are
  • Ecological or natural causes of migration
  • Economic causes of migration
  • Socio-cultural causes of migration
  • Demographic causes of migration
  • Political causes of migration.

3. Discuss the problems of urbanisation.
Answer:

1. Housing and Slums:

• There is a lack of space for housing and a marked reduction in the quality of housing in the urban areas due to increase in population.

2. Over Crowding:

• Over – crowding leads to unhealthy environment in the urban areas.
• It also the cause of many diseases and riots.

3. Water Supply, Drainage and Sanitation:

• No city has round a clock water supply in the world.
• The drainage situation is equally bad.
• The removal of garbage is a Himalayan task for urban local bodies.

4. Transportation and Traffic:

• The absence of planned and adequate arrangements for traffic and transport is another problem in urban centers.
• The increasing number of two-wheeler and cars make the traffic problem worse.

5. Pollution:

• Towns and cities are the major polluters of the environment.
• Several cities discharge their entire sewage and industrial effluents untreated into the nearby rivers. Industries in and around the urban centers pollute the atmosphere with smoke and toxic gases.

IX. Activities
1. List out and analyze the reason for the migration of people in your locality.
Answer:
People migrate for a number of reasons. The reasons and causes for migration would normally fall under these areas:

1. Environmental – Better climate, calamities, and natural disasters are examples of environmental causes or reasons.
2. Economic – Moving to find work or moving to follow a particular career path is an example of economic cause or reason.
3. Cultural – Religious freedom and education is an example of cultural cause or reason.
4. Political – Civil war or escaping from political persecution is an example of a political cause.
5. Social – Moving for a better quality of life or moving closer to a family member or friend is an example of a social cause or reason.

2. Collect the pictures and information regarding the effects of urbanization and make an album.
Answer:

• Slums and Housing
• Overcrowding
• Transportation and traffic
• Pollution.

Samacheer Kalvi 8th Social Science Migration and Urbanisation Additional Important Questions and Answers

I. Choose the Correct answer.
1. The movement of an individual or group to the new country is termed as ………………..
a) Destination
b) Migration
c) Emigrant
d) Immigrant
Answer:
a) Destination

2. Migration is more in ………………. region of the world population.
a) Japan
b) Asia
c) Australia
d) Africa
Answer:
b) Asia

3. In 2017, ………………. was the largest country of origin of international migrants.
a) India
b) America
c) Delhi
d) Asia
Answer:
a) India

4. In ………………., the global urban population exceeded the global rural population.
a) 2005
b) 2006
c) 200
d) 2008
Answer:
c) 2007

5. During the beginning of the ………………. itself many cities were found near the Aegean sea.
a) 6th century
b) 7th century
c) 8th century
d) 5th century
Answer:
b) 7th century

6. In the ancient period the migration was mainly for ………………..
a) Environment
b) Health
c) Food
d) Place
Answer:
c) Food

7. The industrial revolution in the century accelerated the growth of towns and cities.
a) 17^th
b) 18^th
c) 19^th
d) 20^th
Answer:
c) 19^th

8. In 1950, ………………. of the world’s population was urban.
a) 20%
b) 30%
c) 40%
d) 50%
Answer:
b) 30%

9. ………………. is the world’s Highest Population city.
a) Masco (Russia)
b) Shangai (China)
c) Delhi (India)
d) Tokyo (Japan)
Answer:
d) Tokyo (Japan)

10. Migration that occurs the national boundaries are known as
a) Internal migration
b) Voluntary migration
c) International migration
d) Involuntary migration
Answer:
c) international migration

II. Fill in the blank:
1. ………………. is a form of geographical mobility of population between a geographical unit to another.
Answer:
Migration

2. Climatic disasters are ………………. factors.
Answer:
push

3. The movement of people within a country is known as ………………..
Answer:
Internal migration

4. If the migration takes place against the will of migrants is known as ………………..
Answer:
Involuntary migration

5. The migration of agricultural workers during Saving sources is known as ………………..
Answer:
Seasonal migration

6. ………………. is another example of Seasonal migration.
Answer:
Transhumance

7. The number of international migrants in 2017 was ………………..
Answer:
258 million

8. Skilled people from economically backward countries move to developed Countries called ………………..
Answer:
Backwash effect

9. ………………. is the process in which there is an increase in the proportion of population living in towns and cities.
Answer:
Urbanisation

10. The excess production of ………………. was the major reason for urbanisation.
Answer:
foodgrains

11. The ………………. revolution in the 19th century accelerated the growth of towns and cities.
Answer:
industrial

12. Rapid rate of urbanisation results in the development of ………………..
Answer:
Slums

13. In ………………., ………………. regions migrants are predominantly men.
Answer:
Asia, Africa

14. The ………………. factors which attract people towards a location.
Answer:
favourable

15. ………………. is a natural cause of migration.
Answer:
Ecology

III. Match the following:

1. Natural cause	a) War
2. Economic cause	b) Social Discrimination
3. Socio-cultural Cause	c) Unemployment
4. Political Cause	d) Scarcity of food

Answer:

1. Natural cause	d) Scarcity of food
2. Economic cause	c) Unemployment
3. Socio-cultural Cause	b) Social Discrimination
4. Political Cause	a) War

IV. State whether the following statements are true or false.
1. The number of vehicles increase is not the cause of air pollution.
Answer:
False

2. The favourable factors which attract people towards a location.
Answer:
True

3. The movement of people within a country is known as internal migration.
Answer:
True

4. Migration develops both the areas of origin of migration and the areas of destination.
Answer:
False

5. After the 11th century, the European Countries, increased their overseas trade.
Answer:
True

V. Consider the given statements and choose the correct option from the given ones.
1. Statement: Migration may influence the occupational Structure of the Population of an area through this it will certainly affect the economy of the regions also.
Reason: Brain drain refers to the migration in which skilled people from economically backward countries move to developed countries in search of better opportunities,
a) A is correct but R is incorrect
b) Both A and R are incorrect
c) Both A and R are correct
d) A is incorrect and R is correct
Answer:
c) Both A and R are correct

2. Assertion: At the end of the 13th century, Paris London, Geneva, Milan, and Venice were the important cities found in Europe.
Reason: The European countries increased their overseas trade.
a) A is correct but R is incorrect
b) Both A and R are incorrect
c) Both A and R are correct
d) A is incorrect and R is correct
Answer:
c) Both A and R are correct

3. i) Migration that occurs across the national boundaries are known as Internal migration.
ii) If the migration takes place of a person’s free will is known as voluntary migration.
iii) The migration of agricultural workers during Sowing Seasons is known as Seasonal migration.
iv) The migration from rural areas to growing towns and cities mainly in search of employment, education, and recreation facilities.
a) i, iv correct
b) ii correct,
c) ii and iv correct
d) all are correct
Answer:
c) ii and iv correct

VI. Answer the following questions in brief.
1. What are the two factors of migration?
Answer:

• The favourable factors which attract people towards a location are called pull factors.
• The unfavourable factors which make the people to move out from a location are called push factors.

2. What is Backwash Effect?
Answer:

• Brain drain refers to the migration in which skilled people from economically backward countries move to developed countries in search of better opportunities.
• Eventually, this leads to backwardness in source regions. This is called a “backwash effect”.

3. What are the Environmental Consequences that occured during Migration?
Answer:
The overpopulation in urban areas leads to the pollution of air, water, and soil. Scarcity of drinking water, lack of space for housing, traffic congestions, and poor drainage are the common environmental problems that prevail in urban areas.

4. What are the causes of urbanisation?
Answer:

• Urbanisation is driven by three factors: natural population growth, rural to urban migration, and the reclassification of rural areas into urban areas.
• Present-day urbanisation includes changes in demographics, land cover, economic processes, and characteristics of geographic area.

5. What are the noted Prehistoric cities of the world?
Answer:

• Ur and Babylon in Mesopotamia
• Thebes and Alexandria in Egypt
• Athens in Greece
• Harappa and Mohenjodaro in India were noted prehistoric cities of the world.

6. What are the major cities in Africa?
Answer:
Major cities in Africa are Cairo, Nairobi, Mombasa, Bulawayo, Duala, Abidian, Logos, Accra, Addis Abba, Leopoldville, Luanda, Cape Town, Natal, Pretoria.

VII. Distinguish.
1. Short term migration and Long term migration.

Short term migration	Long term migration
1. In this kind of migration, the migrants stay outside only for a short duration before returning to the place of origin.	It is a kind of migration in which the migrants stay outside at least for a few years.
2. The duration may be from a few days to a few months.	The migrants stayed a long time.

VIII. Answer the following questions in detail.
1. Explain Pull factors and Push factors of migration.

Pull factors	Push factors
1. Least hazard-prone zones.	Hazard prone zones.
2. Favourable climate.	Climate change (including extreme weather events).
3. Abundance of natural resources and minerals (e. g. water, oil, uranium).	Crop failure and scarcity of food.
4. Social Unification.	Social Discrimination.
5. Under population.	Overpopulation.
6. Political security.	War, civil, unrest.

2. What are the Consequences of Migration?
a) Demographic consequences:

• It changes the age and sex composition of the population.
• Migration of females after their marriage leads to a decline in sex ratio in the source regions and increases in the sex ratio in the regions of destinations.
• The migration of male workers in search of jobs decreases the independent population of the source regions which increases the dependency ratio.

b) Social consequences:

• The migration of people from different regions towards an urban area leads to the formation of a plural society.
• It helps the people to come out of narrow mindedness and people become generous.

c) Economic consequences:

• The migration of more people from overpopulated to underpopulated regions results in the imbalance of the resource-population ratio.
• In some cases, the regions of over and under population may become the regions of optimum population.
• Migration may influence the occupational structure of the population of an area.
• Through this, it will certainly affect the economy of the regions also.
• Brain drain is a consequence of migration.
• Brain drain refers to the migration in which skilled people from economically backward countries move to developed countries in search of better opportunities
• Eventually, this leads to backwardness in source regions. This is called a “backwash effect”.

d) Environmental consequences:

• Large scale movement of people from rural to urban areas causes overcrowding in cities and puts heavy pressure on resources.
• It leads to the rapid growth of cities.
• The overpopulation in urban areas leads to the pollution of air, water, and soil.
• Scarcity of drinking water, lack of space for housing, traffic congestion, and poor drainage are the common environmental problems that prevail in urban areas.
• The lack of space for housing and the rising land cost lead to the formation of slums.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf Geography Chapter 3 Hydrologic Cycle Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions Geography Chapter 3 Hydrologic Cycle

Samacheer Kalvi 8th Social Science Hydrologic Cycle Text Book Back Questions and Answers

I. Choose the Correct Answer.
1. The process in which the water moves between the oceans, atmosphere and land is called
a) River Cycle
b) Hydrologic Cycle
c) Rock Cycle
d) Life Cycle
Answer:
b) Hydrologic Cycle

2. The percentage of fresh water on the earth is
a) 71
b) 97
c) 2.8
d) 0.6
Answer:
c) 2.8

3. The process of changing of water from gaseous to liquid form is known as
a) Condensation
b) Evaporation
c) Sublimation
d) Rainfall –
Answer:
a) Condensation

4. Water that flows in the sub-soil or through the ground into the streams, rivers, lakes and oceans is termed as
a) Condensation
b) Evaporation
c) Transpiration
d) Runoff
Answer:
d) Runoff

5. The evaporation of water from the leaves of plants is called
a) Transpiration
b) Condensation
c) Water vapour
d) Precipitation
Answer:
a) Transpiration

6. Water that is good enough to drink is called
a) Groundwater
b) Surface water
c) Potable water
d) Artesian water
Answer:
c) Potable water

II. Fill in blank:
1. The degree of water vapour present in the atmosphere is known as …………………
Answer:
weather

2. There are ………………… phases in the water cycle.
Answer:
Three

3. The falling of water towards the earth surface from the atmosphere in any form is known as …………………
Precipitation

4. The precipitation with a rain drop size of <0.5mm in diameter is known as ………………….
Answer:
drizzle

5. Mist is denser than ………………….
Answer:
Clouds

III. Match the following:

1. Vegetation	a) Clouds
2. Condensations	b) Sleet
3. Snow and raindrops	c) At the surface
4. Infiltration	d) Transpiration

Answer:

1. Vegetation	d) Transpiration
2. Condensations	a) Clouds
3. Snow and raindrops	b) Sleet
4. Infiltration	c) At the surface

IV. Choose the correct statement:
1. Evaporation refers to
I. The process in which the gaseous form of water changes into liquid form.
II. It refers to the process in which the liquid form of water changes into a gaseous form.
III. Water boils at 100°C temperature but, it actually begins to evaporate at 0°C.
IV. It is responsible for the formation of clouds.
a) I, IV, and V are correct
b) II only correct
c) II and III are correct
d) All are correct
Answer:
c) II and III are correct

V. State whether thefollowing^statements are True or False:
1. Water boils at 212°F temperature but, it begins to evaporate at 32°F.
Answer:
True

2. Mist is not the tiny droplets of water hanging in the air.
Answer:
False

3. The sub-surface runoff is usually referred to as interflow.
Answer:
True

VI. Answer in brief:
1. Write a short note on the aquifer.
Answer:
An aquifer is an underground layer of water-bearing rock.

2. Define “ hydrological cycle”.
Answer:
The hydrological cycle is a global sun-driven process where water is transported from oceans to the atmosphere, from the atmosphere to land, and from land back to oceans

3. How is the dew formation takes place?
Answer:
Dew is a water droplet formed by the condensation of water vapour on a relatively cold surface of an object. It forms when the temperature of an object drops below the dew point temperature.

4. Write a short note on surface run-off.
Answer:
Surface Runoff is the portion of rainfall, which enters the stream immediately after the rainfall. It occurs when the rainfall is longer, heavier, and exceeds the rate of infiltration. In this condition, the excess water makes a head over the ground surface, which tends to move from one place to another following land gradient and is known as overland flow. When the overland flow joins the streams, channels or oceans, it is termed as surface runoff or surface flow.

VII. Give reasons:
1. Infiltration of water is low in the region of non-porous soil.
Answer:
Because percolation moves the infiltrated water through the soil profile and rock layers to form groundwater.

2. Freshwater is less on the earth.
Answer:
Most of the water on the earth is saline and is found in seas and oceans, which constitutes about 97.2%.

3. Snowfall is common in the polar region and mountainous regions.
Answer:
Often water vapour in a cloud is converted directly into snow pieces due to lowering of temperature and so it is common in the polar and mountainous regions.

VIII. Answer in a paragraph:
1. Explain the different stages involved in the hydrological cycle.
Answer:
The three important phases of the hydrologic cycle are:

• Evapotranspiration,
• Precipitation and
• Runoff.

1. Evapotranspiration:
It is defined as the total loss of water from the earth through evaporation from the surface water bodies and the transpiration from vegetation. In cropped areas, it is difficult to determine the evaporation and transpiration separately. Therefore it is collectively called evapotranspiration.

2. Precipitation:
It refers to all forms of water that fall from clouds and reaches the earth’s surface. For the occurrence of precipitation, cloud droplets or ice crystals must grow heavy enough to fall through the air. When the droplets grow large in size, they tend to all. While moving down, by collecting some small droplets, they become heavy enough to fall out of the cloud as raindrops.

3. Runoff:
Runoff is the water that is pulled by gravity across the land’s surface. It replenishes groundwater and surface water as it percolates into an aquifer (it is an underground layer of water-bearing rock) or moves into a river, stream, or watershed. It comes from unabsorbed water from rain, snowmelt, irrigation or other sources, comprising a significant element in the water cycle as well as the water supply when it drains into a watershed. Runoff is also a major contributor to erosion which carves out canyons, gorges, and related landforms.

2. Distinguish between evaporation and transpiration.

Water boils at 100°C temperature but, it actually begins to evaporate at 0°c. Much of the water taken up by the plants is released through transpiration.

Evaporation	Transpiration
1. The process in which the liquid form of water changes into gaseous form.	The process by which the water content in the plant are released into the atmosphere in the form of water vapour.
3. The amount of water gets evaporated is about the same as the amount of water delivered to earth as precipitaion.	The soil water content and the ability of the soil to conduct water the roots and the nature of the plant parts also determine the transpiration rate.
4. The rate of evaporation is low during the periods of calm winds than during windy times.	The rate of transpiration is affected by the temperature, wind and humidity.

3. Give a detailed explanation on different forms of precipitation.
The form of precipitation in a region depends on the kind of weather or the climate of the region. The Precipitation in the warmer parts of the world is always in the form of rain or drizzle.
In colder region, precipitation may fall as snow or ice.
Common types of precipitation include rain, sleet, freezing rain, hail & snow.

Rain:

• The most common kind of precipitation is rain.
• The precipitation in the form of water droplet is rain.
• Below 0.5 mm in diameter is known as drizzle and above 0.5 mm in diameter is known as rain.

Sleet:
The precipitation which takes place in the form of a mixture of water droplets and tiny particles of ice is known as sleet.

Freezing Rain:

• Raindrops falling through cold air near the ground do not freeze in the air.
• Instead, the raindrops freeze when they touch a cold surface.
• This is called freezing rain.

Hail:
The precipitation which consists of round pellets of ice which are larger than 5mm in diameter is called as hail or hailstones.
Snow:
The precipitation in form of a powdery mass of ice is known as snowfall which is common in the polar and high mountainous regions.

4. Explain the run-off and its types.

Runoff is the water that is pulled by gravity across the land’s surface. It replenishes groundwater and surface water as it percolates into an aquifer (it is an underground layer of water-bearing rock) or moves into a river, stream, or watershed.

Types of Runoff:
Based on the time interval between the instance of rainfall and generation of runoff, the runoff may be classified into the following three types

1. Surface Runoff:
It is the portion of rainfall, which enters the stream immediately after the rainfall. It occurs when the rainfall is longer, heavier, and exceeds the rate of infiltration. In this condition, the excess water makes a head over the ground surface, which tends to move from one place to another following a land gradient and is known as overland flow. When the overland flow joins the streams, channels, or oceans, it is termed as surface runoff or surface flow.

2. Sub – Surface Runoff:
The water that has entered the subsoil and moves laterally without joining the water-table to the streams, rivers or oceans is known as sub-surface runoff. The subsurface runoff is usually referred as interflow.

3. Base Flow:
It is a flow of underground water from a saturated groundwater zone to a water channel. It usually appears at a downstream location where the channel elevation is lower than the groundwater table. Groundwater provides the streamflow during dry periods of small or no precipitation.

Samacheer Kalvi 8th Social Science Hydrologic Cycle Additional Important Questions and Answers

I. Choose the Correct answer.
1. The process of change of water into gaseous form is called ………………….
a) Evaporation
b) Evapotranspiration
c) Precipitation
d) Condensation
Answer:
a) Evaporation

2. …………… is the prime element which affects the rate of evaporation.
a) Temperature
b) Rain
c) Air
d) Mist
Answer:
c) Air

3. The quantity of water present on the earth is about ………………. million cubic miles.
a) 236
b) 263
c) 326
d) 362
Answer:
c) 326

4. …………………. Saturation occurs when the temperature drops down.
a) Air
b) Water
c) Land
d) Soil
Answer:
a) Air

5. ……………… of the moisture form plants through transpiration.
a) 10%
b) 50%
c) 80%
d) 90%
Answer:
a) 10%

6. The evaporation is more than precipitation in the …………………..
a) Oceans
b) Land side
c) Desert land
d) Water Source
Answer:
a) Oceans

7. The process of change of gaseous form of water into liquid form is called as ______________
a) Vapourisation
b) Transpiration
c) Condensation
d) Infiltration
Answer:
c) Condensation

8. An air layer next to the earth’s Surface to 1000 m or lower is called as _____________
a) Dew
b) Frost
c) Fog
d) Mist
Answer:
c) Fog

9. Water entering the soil at the Surface of the ground is termed as _____________
a) Infiltration
b) Percolation
c) Condensation
d) Vaporisation
Answer:
a) Infiltration

10. The flow of water from the unsaturated zone to the Saturated zone is termed as
a) Infiltration
b) Percolation
c) Condensation
d) Vaporisation
Answer:
b) Percolation

II. Fill in the blanks:
1. Water in India is available in Sources.
Answer:
Three

2. Hydrology is the science which deals with the various aspects of water such as ………………, ……………… and ……………….
Answer:
Occurrence, distribution, movement

3. Hydrologic cycle is a global …………….. process.
Answer:
Sun-driven

4. ………………… refers to all forms of water that fall from clouds and reaches the earth’s Surface.
Answer:
Precipitation

5. The three important phases of the hydrologic cycle are …………….., ………………., and ……………..
Answer:
Evapotranspiration, Precipitation, Run off

6. The Sleet falls, the raindrops freeze into solid particles of ………………….
Answer:
ice

7. Most of the water on the earth is …………… in the surface water.
Answer:
Saline

8. ……………….. is available in the form of glaciers.
Answer:
2.15%

9. ……………….. is a continuous process and takes place naturally.
Answer:
Hydrologic cycle

10. Water boils at
Answer:
100PC

11. The water content in salt water oceans is
Answer:
97.2%

12. The amount of Icecaps and glaciers in Fresh water is
Answer:
68.7%

13. The Ground water content in Fresh water is
Answer:
30.1%

14. The boiling point of water is
Answer:
2129F

15. There is a relationship between temperature and evaporation.
Answer:
positive

III. Match the follpwing:

1. Runoff	a) Rain
2. Precipitation	b) Snow
3. Polar region	c) Water springs
4. Infiltration	d) less than 0.5mm
5. Drizzle	e) river

Answer:

1. Runoff	e) river
2. Precipitation	a) Rain
3. Polar region	b) Snow
4. Infiltration	c) Water springs
5. Drizzle	d) less than 0.5mm

IV. Choose the correct statement:
1. a) Water entering the soil at the surface of the ground is termed as infiltration
b) Rain water Soaks into the ground, through the soil and underlying rock layers.
c) Some of the water remains underground and is called ground water.
d) The terms infiltration and percolation are other used inter changeably.
a) I, IV, and V are correct
b) II only correct
c) II and III are correct
d) All are correct
Answer:
d) AH are correct

V. State whether the following statements are True or False:
1. Water in India is available in three sources.
Answer:
True

2. Rain is the tiny droplets of water hanging in the air.
Answer:
False

3. Saturation occurs when the temperature increases.
Answer:
False

4. Evaporation is the process in which the liquid form of water changes into a gaseous form.
Answer:
True

VI. Answer in brief:
1. What are the Sources of water available in India.
Answer:

• Water in India is available in three sources.
• They are precipitation, surface water, and groundwater.

2. What is hydrology?
Answer:
Hydrology is the science which deals with the various aspects of water such as its occurrence, distribution, movement and properties on the planet earth.

3. What are the factors that increase the rate of evaporation?
Answer:

• Increase in wind speed
• Increase in temperature
• Decrease in humidity and
• Increase in the areal extent of surface water bodies.

VII.Give reasons:
1. Availability of water on the earth is not uniform. Why?
Answer:
The availability of water on the earth is not uniform because Some places are very rich and some places are poor in water resources.

2. Distinguish between Frost and Mist.
Answer:

Frost	Mist
1. The ice crystals formed by the deposition of water vapour on a relatively cold surface of an object are known as frost.	Mist is the tiny droplets of water hanging in the air.
2. Density increased	Mist is less dense than fog.

VIII. Answer in a paragraph:

1. Water on the Earth – Explain.
Answer:

• About 71 % of the earth’s surface is covered by water.
• The quantity of water present on the earth is about 326 million cubic miles.
• It is hard to visualise this massive quantity of water.
• Most of the water on the earth is saline and is found in seas and oceans.
• The salt water constitutes about 97.2% and the fresh water is only about 2.8%.
• Out of this 2.8%, about 2.2% is available as surface water and the remaining 0.6% is groundwater. From this 2.2% of surface water, 2.15% is available in the form of glaciers and icecaps, 0.01% in lakes and streams and the remaining 0.04% is in other forms.
• Only about 0.25% of the total ground water of 0.6% can be economically extracted with the present drilling technology.

2. Explain the forms of condensation.
Answer:
Dew, fog, and Clouds are the three major forms of condensation.

• Dew: It is a water droplet formed by the condensation of water vapour on a relatively cold surface of an object.
• Frost: The ice crystals formed by the deposition of water vapour on a relatively cold surface of an object is known as frost.
• Fog: Fog is the suspended tiny water droplets or ice crystals in an air layer next to the earth’s surface.
• Mist: Mist is the tiny droplets of water hanging in the air.
• Clouds: Clouds consist of tiny water droplets/ice particles which are so small and light in weight.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf Geography Chapter 2 Weather and Climate Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions Geography Chapter 2 Weather and Climate

Samacheer Kalvi 8th Social Science Weather and Climate Text Book Back Questions and Answers

I. Choose the correct answer:
1. Earth’s atmosphere contains about percentage of nitrogen and oxygen.
a) 78% and 21%
b) 22% and 1%
c) 21% and 0.97%
d) 10% and 20%
Answer:
a) 78% and 21%

2. ………………. is generally defined as the average conditions of the weather of a place or a region.
a) earth
b) atmosphere
c) climate
d) sun
Answer
c) climate

3. The earth receives energy from
a) current
b) electro magnetic radiation
c) waves
d) heat
Answer:
d) heat

4. Which one the following represents places with equal amount of rainfall
a) isotherm
b) isohel
c) isobar
d) isohytes
Answer:
d) isohytes

5. …………. is used to measure the humidity.
a) anemometer
b) barometer
c) hygrometer d) thermometer
Answer:
c) hygrometer

II. Fill in the blank
1. ……………….. refers to the condition of atmosphere for a short period of time.
Answer:
Weather

2. The scientific study of weather is called ………….
Answer:
Meteroiogy

3. The highest temperature ever recorded on the earth is ……………..
Answer:
56.7°C in in USA

4. …………. is a ratio between the actual amount of water vapour and the maximum amount of water vapour the air can hold.
Answer:
Humidity

5. …………. and ………….. are measured by anemometer and wind vane respectively.
Answer:
Wind direction and wind speed

6. ………… are imaginary lines which connect the same temperatures of different places.
Answer:
Isotherms

III. Match the following

1. Climate	a) Locating and Tracking Storms
2. Isonif	b) Cyclone
3. Hygrometer	c) Equal Snowfall
4. Radar	d) Long Term Changes
5. Low Pressure	e) Humidity

Answer:

1. Climate	d) Long Term Changes
2. Isonif	c) Equal Snowfall
3. Hygrometer	e) Humidity
4. Radar	a) Locating and Tracking Storms
5. Low Pressure	b) Cyclone

IV. State whether the following statements are True or False:
1. The atmosphere is a layer of gases surrounding the planet.
Answer:
True

2. The scientific study of weather is called Climatology.
Answer:
False

3. Isohel refers equal sunshine.
Answer:
True

4. Humidity is calculated by Aneroid Barometer.
Answer:
False

V. Answer in brief:
1. Define ‘weather’.
Answer:
Weather is the day today conditions(state) of the atmosphere at any place as regards sunshine, temperature, cloud cover. Wind fog condition, air pressure, humidity, precipitation and such other elements.

2. What is insolation?
Answer:
Incoming solar radiation are called Insolation.

3. What is meant by atmospheric pressure?
Answer:
The weight of air above a given area on the earth’s surface is called atmospheric pressure or air pressure.

4. Write a short note on “Planetary winds”
Answer:

• Planetary winds are the ones which blow almost in the same direction throughout the year.
• So, they are called as planetary winds.

5. What are “Isolines”?
Answer:
The distribution of weather elements is shown by means of Isolines on maps. Isolines are lines which join the places of equal values of weather elements.

VI. Distinguih the following:
1. Weather and climate.

Weather	Climate
1. Weather is the day today conditions of the atmosphere like sunshine, temperature humidity and such other elements.	Climate is generally defined as the average conditions of the weather of place or a region.
2. Weather is cool in .winter and hot in summer.	The Climate does not change often like weather.

2. Absolute and relative humidity.

Absolute Humidity	Relative Humidity
1. It is the mass or weight of water vapour present per unit volume of air.	It is a ratio between the actual amount of water vapour present in the air and the maximum amount of water vapour it can hold at given temperature.
2. These expressed usually in grams per cubic meter of air.	It is expressed as a percentage.

3. Permanent and seasonal winds.

Permanent wind	Seasonal wind
1. Permanent winds, are also called planetary winds.	Monsoon winds are also called as seasonal winds.
2. These winds blow almost in the same direction throughout the year.	These winds are blowing from sea to land during summer and land to sea during winter.

VII. Give reasons:
1. The Weather and climate in different regions vary.
Answer:
The angle of the sun’s rays, the length of daytime, altitude, distribution of land and water bodies, location and direction of mountain ranges, air pressure, winds, and ocean currents are the major factors which affect the weather and climate of a region.

2. Temperature decreases with an increase in altitude.
Answer:
It is known as the Lapse rate which is 6.5-degree Celcius per 1000 meters is the troposphere.

3. Mountain climbers carry Oxygen cylinders while ascending peaks.
Answer:
With decreasing air pressure, the availability of oxygen to breathe also decreases. At very high altitudes, atmospheric pressure and available oxygen get so low that people can become sick and even die. Mountain climbers use bottled oxygen when they ascend very high peaks.

VIII. Answer in a paragraph:
1. How is temperature measured?
Answer:
Measuring Temperature:
1. The temperature of a unit volume of air at a given time is measured in scales like Celsius, Fahrenheit, and Kelvin. Meteorologist measures the temperature by the Thermometer, Stevenson screen and minimum and maximum Thermometer.

2. The energy received by the earth through insolation is lost by outgoing radiation.

3. Atmosphere is mainly heated by outgoing radiation from 2 to 4 pm. So the maximum temperature is recorded between 2 and 4 pm regularly and the minimum temperature is recorded around 4 am before sunrise.

Mean Temperature:
1. The average of the maximum and minimum temperatures within 24 hours is called mean daily temperature [(87°F + 73°F)/2=80°F].

2. Diurnal range of temperature is the difference between the maximum and minimum temperatures of a day. The annual range of temperature is the difference between the highest and lowest mean monthly temperatures of a year.

2. Write about the wind and its types.
Answer:
The horizontal movement of air is called wind. The wind systems are broadly categorized into three as follows.

• Planetary winds
• Seasonal winds
• Local winds

1. Planetary Winds are the ones which blow almost in the same direction throughout the year. So, they are called as Permanent or planetary winds. Trade winds, Westerlies, and polar easterlies are the types of prevailing winds.

2. Seasonal winds are those which change their direction according to the season in a year. They are called as monsoon winds. These winds blow from sea to land during summer and land to sea during winter.

3. Local winds are the winds that blow over a small area only during a particular time of a day or a short period of a year. Land and sea breezes are examples of these winds.

3. List out the weather elements and associated measuring instruments.
Answer:

Weather elements	Measuring instruments
Temperature	Celsius, Fahrenheit, Kelvin
Rainfall	Rain gauge
Air Pressure	Aneroid Barometer
Humidity	Hygrometer
Wind	Anemometer

IX. Give any three suggestions to reduce global warming:

1. Plant trees.
2. Recycle the used things.
3. Composite wasted food and biodegradables.

Samacheer Kalvi 8th Social Science Weather and Climate Additional Important Questions and Answers

I. Choose the Correct answer:
1. The word Klimo is derived from the language.
a) Greek
b) Latin
c) Arab
d) English
Answer:
a) Greek

2. Horizontal movement of air is called
a) Storm
b) Cyclone
c) Mist
d) Wind
Answer:
d) Wind

3. The average wind speed is low in
a) France
b) Canada
c) Argentina
d) Brazil
Answer:
d) Brazil

4. The temperature decreases per 1000 meters height is
a) 5°C
b) 6.5°C
c) 7°C
d) 8.5°C
Answer:
b) 6.5°C

5. …………….. is the difference between the maximum and minimum temperatures of a day.
a) Diurnal range
b) Heat conduction
c) Heat radiation
d) Heat elevation
Answer:
a) Diurnal range

6. Which Zone is called a Tropical Zone?
a) Torrid zone
b) Temperate zone
c) Frigid zone
d) Polar zone
Answer:
a) Torrid zone

7. Isobar means
a) Equal Sunshine
b) Equal atmospheric pressure
c) Equal temperature
d) Equal rainfall
Answer:
b) Equal atmospheric pressure

8. The name of an Equal amount of rainfall is
a) Isotherm
b) Isohel
c) Isohyet
d) Isollobar
Answer:
c) Isohyet

9. The name of Equal pressure tendency is
a) Isotherm
b) Isohel
c) Isohyet
d) Isollobar
Answer:
d) Isollobar

10. Major element of weather and climate is
a) Temperature
b) Sound
c) Light
d) Latitude
Answer:
a) Temperature

II. Fill in the blanks:
1. Heat energy from ………………. is received by the earth through three mechanisms.
Answer:
Solar radiation

2. ……………. and soil are the major factors which affect the distribution of temperature.
Answer:
Natural vegetation

3. The distribution of temperature is shown by means of ………………..
Answer:
Isotherms

4. Temperature zone lies between tropic of …………… circle in the Northern Hemisphere and the ………………. circle in the Southern Hemisphere.
Answer:
Arctic, Antarctic

5. Frigid zone is known as …………………
Answer:
polar region

6. ………………… is a major component of the water cycle.
Answer:
Rain

7. Generally rainfall is high in the …………….. region.
Answer:
Equatorial

8. The average of ……………. and ……………. temperatures within 24 hours is called mean daily temperature.
Answer:
maximum, minimum

9. …………………. is a diagram used to depict the direction and periods of prevailing winds on a map.
Answer:
Wind rose

10. Weather is the day to day conditions of the ………………………..
Answer:
atmosphere

11. The amount of carbon dioxide in the atmosphere is ………………..
Answer:
0.03%

12. The amount of argon in the atmosphere is …………….
Answer:
0.97%

13. The word Klimo means ……………….
Answer:
Inclination

14. Climate is the average atmospheric conditions usually for ………………..
Answer:
35 years

15. The Scientific Study of Climate is called …………….
Answer:
Climatology

III. Match the following:

1. Aniroid	a) Temperature
2. Beaufort	b) diagram
3. Wind rose	c) Wind speed
4. Fahrenheit	d) humidity
5. Hydrometer	e) air pressure

Answer:

1. Aniroid	e) air pressure
2. Beaufort	c) Wind speed
3. Wind rose	b) diagram
4. Fahrenheit	a) Temperature
5. Hydrometer	d) humidity

IV. State whether the following statements are True or False:
1. The highest temperature ever recorded on the earth is 56.7°C.
Answer:
True

2. The degree of heat present in the sun is termed as temperature.
Answer:
False

3. Rainfall is measured by Raingauge.
Answer:
True

4. Temperature decreases to 8°C per 1000 meters in height.
Answer:
False

5. Al-Balakhi prepared the first climatic Atlas of the world.
Answer:
True

V. Answer in brief:
1. What are the Controlling factors of weather and climate?
Answer:
The angle of the sun’s rays, the length of daytime, altitude, distribution of land and water bodies, location and direction of mountain ranges, air pressure, winds, and ocean currents are the major factors which affect the weather and climate of a region.

2. What are the factors affecting the distribution of temperature?
Answer:
Latitude, altitude, nature of the land, ocean currents, prevailing winds, slope, shelter, and distance from the sea, natural vegetation, and soil are the major factors which affect the distribution of temperature.

3. What are the Isotherms?
Answer:

• The distribution of temperature is shown by means of Isotherms.
• Isotherms are imaginary lines which connect the same temperatures of different places..

VI. Distinguish the following:
1. Torrid zone and Temperature zone.

Torrid zone	Temperature zone
1. It is a region between the tropic of cancer and the tropic of Capricorn.	This zone lies between the Tropic of cancer and the Arctic circle in the Northern Hemisphere and between the Tropic of Capricorn and the Antarctic circle in the Southern Hemisphere.
2. This region receives the direct rays of the sun and gets the maximum heat from the sun.	This zone gets the slanting rays of the sun
3. This zone is known as the tropical zone.	The angle of the sun’s rays goes on decreasing towards the poles.

2. Specific humidity and Relative humidity.

Specific humidity	Relative humidity
1. Specific humidity is a ratio of the water vapor content of the mixture to the total air content on a mass basis.	The relative humidity is a ratio between the actual amount of water vapour present in the air and the maximum amount of water vapour.
2. It is expressed in grams of vapour per kilogram of air.	It is expressed as a percentage.

VII. Give reasons:
1. Why artificial pressure creates in Aircraft?
Answer:

• At very high altitudes, atmospheric pressure and available oxygen get so low as the quick move from high pressure to low pressure can cause decompression sickness.
• Aircraft create artificial pressure in the cabin which makes the passengers remain comfortable while flying.

VIII. Answer in a paragraph:
1. Define the types of humidity.
Answer:
The types of humidity are

• Specific humidity
• Absolute humidity
• Relative humidity

Specific humidity:
Specific humidity is a ratio of the water vapor content of the mixture to the total air content on a mass basis. It is expressed in grams of vapour per kilogram of air.

Absolute humidity:
Absolute Humidity is the mass or weight of water vapour present per unit volume of air.

Relative humidity:
It is a ratio between the actual amount of water vapour present in the air and the maximum amount of water vapour it can hold at a given temperature.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Social Science Guide Pdf Geography Chapter 1 Rocks and Soil Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 8th Social Science Solutions Geography Chapter 1 Rocks and Soil

Samacheer Kalvi 8th Social Science Rocks and Soil Text Book Back Questions and Answers

I. Choose the correct answer:

1. Which of the following is known as sphere of rocks
a) Atmosphere
b) Biosphere
c) Lithosphere
d) Hydrosphere
Answer:
(c) Lithosphere

2. World soil day is observed on
a) 15th August
b) 12th January
c) 15th October
d) 5th December
Answer:
(d) 5th Decembe

3. Fossils are found in
a) Sedimentary rocks
b) Igneous rocks
c) Metamorphic rocks
d) Plutonic rocks
Answer:
(a) Sedimentary rocks

4. The top layer of soil is called as
a) organic layer or humas
b) topsoil
c) subsoil
d) bedrock
Answer:
(b) topsoil

5. Ideal soil for growing cotton is
a) Red soil
b) Black soil
c) Alluvial soil
d) Mountain soil
Answer:
(b) Black soil

6. The major components of soil is
a) Rocks
b) Minerals
c) Water
d) All the above
Answer:
(b) Minerals

7. Which one of the following is the most widespread most and productive category of soil
a) Alluvial soil
b) Black soil
c) Red soil
d) Mountain soil
Answer:
(a) Alluvial Soil

II. Fill in the blanks.

1. Scientific study of rocks is called …………….
Answer:
Petrology

2. ……………. soil is highly suitable for millets cultivation.
Answer:
Black

3. The “Skin of earth” is
Answer:
Soil

4. ……………. is the kind of metamorphic rock using which Taj Mahal was built.
Answer:
White marble

5. ……………. is known as the primary rocks.
Answer:
Igneous rock

True or False:

1. Igneous rocks are called primary rocks.
Answer:
True

2. Slate is formed from shale.
Answer:
True

3. Red soil is formed by the process of leaching.
Answer:
False

4. M-sand is used as alternative for natural sand in construction.
Answer:
True

5. Volcanic mountains are covered with sedimentary rocks.
Answer:
True

IV. Match the following:
1.

Answer:
A) 2 14 3

2.

Ans: D) 3, 1, 4, 2

V. Choose the incorrect statement from the following:

1. a) Igneous rocks are called the primary rocks.
b) Soil is the product of weathering of rocks.
c) Sedimentary rocks are the hardest ones.
d) Deccan plateau is the region of Igneous rocks.
Answer:
d) Deccan plateau is the region of Igneous rocks.

2. a) Soil erosion decreases its fertility.
b) Dynamic metamorphism is caused by high temperature.
c) Soil is a renewable source.
d) Humus is a part of the top layer of soil.
Answer:
c) Soil is a renewable source.

VI. Consider the. following statements and choose the right option from the given ones:
Statement (1): Sedimentary rocks consist of many layers.
Statement (2) : Sedimentary rocks are formed by the sediments deposited at different points of time.
(a) 1 and 2 are correct and 2 explains 1
(b) 1 and 2 are correct but, 2 does not explain 1
(c) 1 is correct but, 2 is incorrect
(d) 2 is correct but, 1 is incorrect.
Answer:
(a) 1 and 2 are correct and 2 explains 1

VII. Give reasons for the following:

1. Chemical sedimentary rocks are found in the beds of reservoirs.
Answer:
Chemical Sedimentary rocks are formed by the precipitating minerals from water. It is formed usually through the evaporation of chemical-rich solutions.

2. Igneous rocks are found in the regions of volcanoes
Answer:
The formation of igneous rocks takes place when there is an outflow of molten magma.

VIII. Distinguish the following:
1. Metamorphic rock and sedimentary rock.

	Metamorphic rocks	Sedimentary rocks
i)	A rock formed by the alteration of igneous and sedimentary rocks subject to the high temperature and pressure is called metamorphic rocks.	Due to high temperature and pressure, the undisturbed sediments of long period is cemented to form sedimentary rocks.
ii)	Metamorphism is of two types: a) Thermal Metamorphism and b) Dynamic Metamorphism.	Sedimentary rocks are of three types: a) Organic Sedimentary rocks, b) Mechanical Sedimentary rocks and c) Chemical Sedimentary rocks.

2. Soil conservation and Soil erosion.

	Soil conservation	Soil erosion
i)	The process of protecting the soil from erosion to maintain its fertility.	The removal or destructive of the top layer of soil by natural forces and human activities.
ii)	Practised for the conservation of afforestation, controlled grazing, construction of dams, crop rotation, wind break, etc.	Reduces the fertility of soil which leads to the reduction in the agricultural productivity.

IX. Give short answers
1. How are igneous rocks formed?
Answer:
The igneous rocks are formed by the solidification of molten magma.

2. Describe about the composition of soil.
Answer:

• The basic components of soil are mineral, organic matter, water and air.
• It consists of about 45% mineral, 5% organic matter, 25% of water, and 25% air.
• The composition of soil varies from place to place and from time to time.

3. Define ‘rock’.
Answer:

1. The rocks are the solid mineral materials forming a part of the surface of the earth and other similar planets.
2. A rock is an aggregate of one or more minerals. Rock is an important natural resource and is found in solid-state.
3. It may be hard or soft in nature.

4. State the types of soils.
Answer:

• Alluvial soil
• Black soil
• Red soil
• Laterites soil
• Mountain soil
• Desert soil

5. What is soil conservation?
Answer:
Soil conservation is the process of protecting the soil from erosion to maintain its fertility.

X. Give a detailed answer for the following:
1. Explain the process of soil formation.
Answer:
Soil and its Formation:

Igneous:
(i) The igneous rocks are formed by the solidification of molten magma. Also called Primary or Parent Rocks.
(ii) Types:

• Extrusive Igneous Rocks.
• Intrusive Igneous Rocks

1. Extrusive Igneous Rocks:
Molten magma which comes out from the interior of the earth’s surface gets solidified and forms such rocks. Fine-grained and glassy in nature. Eg., Basalt, found in northwestern peninsular India.

2. Intrusive Igneous rocks:
Molten magma cools down deep inside the earth’s crust, becomes solid and forms such rocks. Form large grains. Deep seated rocks are plutonic rock and ones at shallow depths – Hypabysal rocks. Example Granite, Diorite.

Sedimentary:
(i) Formed by the sediments derived and deposited by various agents. Also called stratified rocks.
(ii) Types:

• Organic sedimentary rocks
• Mechanical sedimentary rocks,
• Chemical sedimentary rocks

1. Organic sedimentary rocks:
Formed due to decomposition of dead Plants and Animals. Contains fossils. Example Chalk, Talc

2. Mechanical sedimentary rocks:
Formed from the disintegration of Igneous and metamorphic rocks. Get deposited due to erosion by natural agents. Get cemented after a long time to form rocks. Example Sandstone, Shale.

3. Chemical sedimentary rocks: Formed by precipitating of minerals from water. Formed due to evaporation of chemical rich solution. Example Rock Salt.

Metamorphic:
(i) Formed when Igneous and sedimentary rocks are subjected to high temperature and pressure.
(ii) Types:

• Thermal
• Dynamic

1. Thermal Metamorphic:
If the change in rocks is caused by high temperature.

2. Dynamic Metamorphic:
If the change in rock is caused by high pressure. Formed from Igneous rocks. Eg., Granite into gneiss
Formed from Sedimentary rocks. Eg., Shale into Slate

3. Give an account of different layers of soil.
Layers of soil:
O – Horizon or humus:
This layer is dominated by organic material eg: leaves
A – Horizon or Topsoil:
It is a part of topsoil composed of organic matter mixed with mineral matter.
E – Horizon or Elevated layer:
E – stands for the elevated layer. This layer is significantly leached of clay, iron and aluminium oxides, which leaves a concentration of ore.
B – Horizontal or subsoil:
This layer reflects the chemical or physical alternation or parent material. Thus iron, clay, aluminium and organic compounds are found accumulated in the Horizon.
C – Horizon or Parent Rock:
Partially weathered parent material accumulates in this layer.
R – Horizon or Parent Rock:
This layer consists of an unweathered part of the bedrock.

4. Classify and explain the soil?
Answer:
Definition: Soil is a mixture of Organic matter, minerals, gases, liquids, and organisms that together support life.

Classification of soils:
Soils are classified on the basis of their formation, colour, physical and chemical properties. Based on these, soil is classified into six major types. They are Alluvial soil, Black soil, Red soil, Laterite soil, Mountain soil, Desert soil.

Alluvial soil:

• Found in the regions of river valleys, flood plains, and coastal regions.
• Formed by the deposition of silt by the running water.
• Most productive of all soils.
• Suitable for the cultivation of sugarcane, jute, rice, wheat.

Black soils:

• Formed by weathering of igneous rocks.
• Clayey in nature.
• Retains moisture.
• Ideal for growing cotton.

Red Soils:

• Formed by weathering of metamorphic rocks and crystalline rocks.
• Found in semi-arid regions.
• Not a fertile.
• Is soil brown-red in colour due to the presence of iron oxide
• Suitable for millet cultivation.

Laterite soils:

• Formed by the process of leaching.
• Found in trophical regions, which experienced the alternate wet and dry conditions.
• Infertile soil.
• Suitable for plantation of tea and coffee.

Mountain soils:

• Found in slopes of mountains.
• Thin and acidic in nature.
• The nature of soil differs based on the altitude.

Desert soils:

• Found in the hot desert region.
• Porous and saline in nature.
• Infertile in nature.
• Agriculture is not successful.

XI. Activity Corner.

1. Complete the following table with the help of an internet source.

Samacheer Kalvi 8th Social Science Rocks and Soil Additional Important Questions and Answers

I. Choose the Correct answer.
1. Petrology is derived from the ………….. word.
a) English
b) Latin
c) Greek
d) French
Answer:
(c) Greek

2. The soils found in the desert regions are …………..
a) Mountain Soils
b) Desert Soils
c) Black Soil
d) Red Soil
Answer:
(b) Desert Soils

3. Which Soils are formed by the weathering of metamorphic rocks?
a) Red Soils
b) Rock Soils
c) Laterite Soils
d) Mountain Soils
Answer:
(a) Red Soils

4. …………….. is a part composed of organic matter mixed with mineral matter.
a) Humus
b) Top Soil
c) Elevated layer
d) Sub-soil
Answer:
(b) Top Soil

5. The time to form one cm of soil is
a) 100 years
b) 200 years
c) 500 years
d) 1000 years
Answer:
(b) 200 years

6. …………….is known as the zone of accumulation.
a) Humus
b) Top Soil
c) Elevated layer
d) Sub-soil
Answer:
(d) Sub-soil

7. In the soil composition ………….. are minerals.
a) 5%
b) 10%
c) 25%
d) 45%
Answer:
(d) 45%

8. In the soil composition is air.
a) 5%
b) 10%
c) 25%
d) 40%.
Answer:
(c) 25%

9. ……………. soils are formed by the deposition of silt by the running water.
a) Black
b) Red
c) Alluvial
d) Desert
Answer:
(c) Alluvial

10. the Soil composition is organic matter.
a) 5%
b) 10%
c) 25%
d) 45%
Answer:
(a) 5%

II. Fill in the blanks:
1. A rock is an aggregate of ………….. or more minerals.
Answer:
one

2. There are ………….. different types of minerals found on the earth Surface.
Answer:
2000

3. Rocks are classified in to ………….. types.
Answer:
three

4. The two types of Intrusive Igneous rocks are ………….., …………..
Answer:
Plutonic rocks, Hypabysal rocks

5. Igneous Rocks are ………….. rocks
Answer:
Primary

6. ……………. into slate caused by thermal metamorphism.
Answer:
Basalt

7. Soil is a basic requirement for the growth of ………….. and …………..
Answer:
Plants, animals

8. To become a well-matured soil, it takes about ………….. years.
Answer:
3000

9. Parent Rock is converted to loose Rock by ……………
Answer:
soil

10. Laterite soil is suitable for plantation crops like ………….., …………..
Answer:
tea, coffee

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

1. To become a well-matured soil, it taken about 2000 years.
Answer:
False

2. Lava comes out from a volcano.
Answer:
True

3. The word Ignis means rock.
Answer:
False

4. Oldest Sedimentary rocks of the world has been identified in Green land.
Answer:
True

5. Soil supports ecosystem and play an important role in land management.
Answer:
True

IV. Match the following:
1.

Answer:
D) 3 1 4 2

V. Choose the incorrect statement from the following:
1. a) Basalt into slate caused by thermal metamorphism.
b) Chemical Sedimentary rocks are also called evaporates.
c) Taj Mahal in India was built with white marbles of Sedimentary rocks.
d) Rocks have been used by mankind throughout history.
Answer:
c) Taj Mahal in India was built with white marbles of Sedimentary rocks.

VI. Consider the following statements and choose the right option from the given ones:
1. Statement (1): Petrology is a branch of geology.
Statement (2): It deals with the Study of water researches.
a) 1 and 2 are correct and 2 explains 1
b) 1 and 2 are correct but, 2 does not explain 1
c) 1 is correct but, 2 is incorrect
d) 2 is correct but, 1 is incorrect.
Answer:
c) 1 is correct but, 2 is incorrect

VII. Give reasons for the following:
1. Why soil is known as ‘Skin of the earth’?

• Soil minerals form the basis of soil.
• It forms on the surface of the earth.
• so It is known as the ‘Skin of the earth’:

VIII. Distinguish the following:
1. Black Soil and Red Soil.

	Black Soil	Red Soil
1.	These Soils are formed by the weathering of igneous rocks.	These soils are formed by the weathering of metamorphic rocks and crystalline rocks.
2.	It is retentive of moisture.	Iron Oxide is present.
3.	It is ideal for growing cotton.	It is Suitable for millet cultivation.

IX. Give short answers:
1. Explain about Petrology.

• Petrology is a branch of geology which deals with the study of rocks.
• ‘Petrology’ is derived from the Greek word “Petrus” refers to rock and “Logos” refers to study

2. Name the layer in the Earth.
The layer found in the Earth are namely

• Lithosphere
• Hydrosphere
• Atmosphere
• Biosphere.

3. Explain the type of Igneous Rocks.

• Extrusive Igneous Rocks
• Intrusive Igneous Rocks.

X. Give a detailed answer for the following:
1. What are the uses of soil?
Answer:
Soil is one of the important natural resources. It is a basic requirement for plant growth and supports various life forms on the earth.

• The minerals present in the soil enhance and nourishes the crops and plants.
• It is used in the making of ceramics or pottery.
• It is a source of material for construction and handicraft works.
• It acts as a natural filter of water and purifies it.
• Soil supports the ecosystem and plays an important role in land management.

Tamilnadu State Board New Syllabus Samacheer Kalvi 8th Maths Guide Pdf Chapter 7 Information processing InText Questions Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Chapter 7 Information processing InText Questions

Recap (Text Book Page No. 232 & 233)

Question 1.
Find the number of all possible triangles that can be formed from the triangle given below.
Answer:
Single Triangles ⇒ 5
Combination of 2 ⇒ 4
Combination of 3 ⇒ 2
Big triangle ⇒ 1
= 12

Question 2.
Use the numbers given in the figure to form a 3 × 3 magic square.

Answer:

Question 3.
Convert the tree diagram into a numeric expression.

Answer:
(10 × 5) + (9 × 4)
= 50 + 36
= 86

Question 4.
(i) Find the total time taken by the bus to reach from A to E via B , C and D.
(ii) Find which is the shortest route from A to E.

Answer:
(i) Route ⇒ A → B → C → D → E
Time taken ⇒ (7 + 5 + 3 + 6) hrs = 21 hrs

(ii)

Available roots	Time taken
(a) A → B → C → D → E	7 + 5 + 3 + 6 = 21 hrs
(b) A → B → D → E	7 + 4 + 6  = 17 hrs
(c) A → B → C → E	7 + 5 + 8 = 20 hrs

Shortest route ⇒ A → B → D → E

Question 5.
Connect the Fibonacci squares through diagonals by curve from corner to corner across each square to draw a Golden Spiral.

Fibonacci Squares

Question 6.
When you plan to buy a shirt, one shop offers a discount of ₹ 200 on MRP ₹ 1000 and another shop offers 15% discount on the same MRP. Where would you buy?
Answer:
Price in 1^st shop = ₹ 1000 – ₹ 200 = ₹800

In shop 1.

Question 7.
Amazing park is offers a package deal of 5 entrance passes for ₹ 130. If one entrance pass normally costs ₹ 30, how much will you save by taking advantage of this special deal?
Answer:
Cost of one entrance pass = ₹ 30
∴ Cost of 5 entrance passes = ₹ 5 × 30
= ₹ 150
But special deal price = ₹ 130
Amount of saving = 150 – 130 = ₹ 20

Activity (Text Book Page No. 237)

Question 1.
Determine the number of two digit numbers that can be formed using the digits 1, 3 and 5 with repetition of digits allowed.
The activity consists of two parts
(i) Choose a one’s digit.
(ii) Choose a ten’s digit.
Complete the table given beside

Answer:

Question 2.
Find the three digit numbers that can be formed using the digits 1, 3 and 5 without repetition of digits.
Complete the tree diagram given below to the numbers

Answer:

Activity (Text Book Page No. 242)

Question 1.

(i)

(ii)

(iii)

Answer:

Question 2.

Answer:
(i)

(ii)

(iii)

Answer:

Question 3.

(i)

(ii)

(iii)

Answer:

Question 4.

(i)

(ii)

(iii)

Answer:

Question 5.

(i)

(ii)

(iii)

Answer:

Try These (Text Book Page No. 243)

Question 1.
Find any five SETs among these set of cards (repetition of cards allowed).
a.

b.

c.

d.

e.

f.

g.

h.

i.

j.

Answer:
(i) (a), (c), (h)
(ii) (e), (g), (j)
(iii) (a), (b), (d)
(iv) (f), (i), (j)
(v) (f), (i), (h)

Question 2.
This is an example for a magic square in SETs. Can you make another two?

Answer:
Repeat one square with every thing 2 another square with everything 3.

Activity (Text Book Page No. 250)

Using the given Table I, find the pattern, answer the following questions and colour the values in the given Table Il. One is done for you.
Table – 1

Question 1.
Where are the even Fibonacci Numbers?
Colour both the term n and where F(n) is even in yellow.
Do you find any pattern?
Every Third Fibonacci number is a multiple of 2(even).
Answer:
i.e., a multiple of F(3) or 2 = F(3)

Question 2.
Where there are Fibonacci numbers which are multiple of 3?
Colour both the term n and where F(n) is multiple of 3 in red.
Write down the pattern you find
Every 4^th Fibonacci number is a multiple of 3.
Answer:
i.e., a multiple of F(4) or 3 = F(4)

Question 3.
What about the multiple of 5?
Colour both the term n and where F(n) is multiple of 5 in blue. ‘
Write down the pattern you find.
Every …………………………… i.e ………………………………
Answer:
Every 5^th Fibonacci number i.e a multiple of F(5) or 5 = F(5)

Question 4.
What about the multiple of 8?
Colour both the term n where F(n) is multiple of 8 in green.
Write down the pattern you find.
Every …………………………… i.e ………………………………
Answer:
Every 6^th Fibonacci number i.e a multiple of F(6) or 8 = F(6)

Table 2.

From the above activity, we conclude that
Every Fibonacci number is a factor of (a term number of) Fibonacci numbers in multiples

From the above table, we get a general rule as Every k^th Fibonacci number is a multiple of F(k).
Answer:
Table 2.

R – Red
Y – Yellow
B – Blue
G – Green

Activity (Text Book Page No. 258)

Code 1: Pigpen

I. Fill in the blank boxes and decode
The Pigpen code looks like meaningless writing, but it is quite easy to catch on to. Each letter is represented by the part of the “Pigpen” that surrounds it.
The first code uses the following key. To complete the code, you need to work out how to use the key to decode the message.

Answer:

To decode

Code 2: Polybius Square Cipher

II. Fill in the blanks
A Polybius Square is a table that allows someone to convert letters into numbers. Use the Polybius square rows and column values to find the code

Answer:
Using this a set of numbers can be used to denote a letter and vise versa
(4, 2) represent T, (3, 4) represent H, (5, 5) represent E
Likewise, when we solve for the remaining. we get
THE NAME OF TREASURE DOES NOT HAVE BAND D .
Since clue 2 gives that the treasure item does not have the letters b & d, therefore “exam pad” & “geometry box” cannot be the treasure item.
Hence, the treasure item is “gift voucher”

Code 3: Atbash Cipher
III. Find the code using the key as shown in given figure:
Atbash cipher is a substitution cipher with just one specific key where all the letters are reversed that is A to Z and Z to A.

Answer:
The given Cipher is:
GSV ILLN MFNYVI RH Z NFOGRKOV LU ULFI ZMW HVEVM
Decoded Message:
THE ROOM NUMBER IS A MULTIPLE OF FOUR AND SEVEN
Since room number is a multiple of 4 & 7,
The room number is 4 × 7 = 28.

Code 4: Using a Key – Reflection Table
IV Use the reflection table which is given below and find the correct word by using a reflected alphabet.

J V A Q B J – _______
P B Z C H G R E G N O Y R – _______
P U N V E – ________
P H O O B N E Q – ________
Answer:
J V A Q B J – WINDOW
P B Z C H G R E G N O Y R – COMPUTER TABLE
P U N V E – CHAIR
P H O O B N E Q – CUPBOARD

After finding the codes, the teacher then asks students to rearrange the clues one by one
CLUES
1. ————————————————-
2. ————————————————-
3. ————————————————-
4. ————————————————-
Answer:
The 4 clues are:
1. Water bottle, Gift voucher, Exam pad, Geometry box
2. The name of the treasure does not have b’ & ‘d’
3. The room is a multiple of four and seven – 28
4. Window, Computer table, Chair, Cupboard

RESULT
(i) The room in which the treasure took place = ________ .
(ii) The place of the treasure = ________ .
(iii) The identity of the treasure = ________ .
(Hint:- If you answered the question number 6 in Exercise 4.3, you can compare and verify your results) The gift voucher contains (20 full marks awarded).
Answer:
The room in which the treasure took place = 28
The place of treasure = Chair
Identity of treasure = Gift voucher.

Try These (Text Book Page No. 260)

Question 1.
Use Pigpen Cipher code and write the code for your name _______ and your chapter names
(i) LIFE MATHEMATICS
(ii) ALGEBRA
(iii) GEOMETRY
(iv) INFORMATION PROCESSING
Answer:
For Pigpen, we should first construct the Criss Cross pattern & then fill with alphabets.
Step 1:

Step 2: Fill the above with all the alphabets from A to Z.

Step 3: So, the secret code is got by the outline of each letter in the above patterns.

similarly for all the others. Therefore pigpen code is


Let us now write the given words with Pigpen code.

Question 2.
Decode the following Shifting and Substitutmg secret codes given below. Which one is easier for you?
(i) Shifting method:- M N S G H M F HR H L O N R R H A K D

Answer:
Decode using shifting method. Let us shift & see by trial & error method.
Let us substitute ‘b’ for ‘a’, ‘e’ for ‘b’ & so on

Message : M N S G H M F H R H L O N R R H A K D
Decoded text : NOTHING IS IMPOSSIBLE

We find that Pigpen code has been used, by substituting for the symbols from the table that we constructed earlier, we go the message.
NOTHING IS IMPOSSIBLE

Question 3.
Write a short message to a friend and get them to decipher it.(Use any one shifting and substituting code method)
Answer:
Student can choose and tr on their own.

Activity (Text Book Page No. 264)

Consider that you are going to a store with your total budget of ₹ 220 to buy things without changing the quantity of the items given in the list below with the following conditions.

Conditions:
(i) First you have to complete the price list given.
(ii) You have to buy three items as per the given price list but within your budget ₹ 220.
(iii) You wont carry exceeding 5kg because you have to walk home carrying them, so they cannot be bulky.

Now, answer the following questions:
1. In how many ways can you buy your items? Complete the price lists given below. One is done for you.
2. Which one is the best purchase price list and why?

Answer:

Answer:

Answer:

Answer:

Answer:

Activity (Text Book Page No. 265)

Consider that you want to buy 12 litres of the same quality of edible oil at your budget price of ₹ 250 per litre. In a supermarket, there are a lot of offers on various oil brands. Some of the offers are given below. Complete the table and find which one is the best offer for you and how much you will save for your total purchase.

Best offer price for you ___________
Amount that you saved for your total purchase ___________
Answer:
Best offer price for you ₹ 137.50
Amount that you saved for your total purchase ₹ 1350

Try These (Text Book Page No. 266)

The teacher divides the class into four groups and setup a mock market in the class room and ask the students to involve in role play as Iwo groups of businessmen and two groups of consumers. Consumers have to buy products at different shops and prepare a price list.

The Iwo supermarkets iii which the two groups buy are Star Food Mart and Super Provisions. Th is week they each have got a special deal on some products. At Star Food Mart. you can buy items at discount prices. At Super Provisions, there are some “BUY ONE GET ONE” deals. Have a look at their deal:

Now answer the following questions.
I. Here is your shopping list:
4 bottles of Protein Milk (200 ml size) 2 packets of Peanut candies(200 gm), 1 packet of Chocolate biscuits, 1 packet of Badam nuts (500 gm)
Answer:
price of Star Food Mart

(i) If you buy all the items in one shop, where will you get the best price?
Answer:
In star Food Mart

(ii) If you buy the items from the two shops, how will you do it to spend the least amount of money?
Answer:
Badam nuts from super provisions and other items from Star Food Mart.

II. You have H 000/- to spend to buy the following shopping list:
6 bottles of Protein Milk (200 ml size), 3 packets of Peanut candies(200 gm), 3 packets of Chocolate biscuits, 1 packet of Badam nuts (250 gm).
Answer:
Comparing two stores

(i) How can you do this so that you dont go over your budget amount ₹ 1000?
Answer:
We can buy them from any one shop.

(ii) Which shop offers you the best value for money on each item?
Answer:
Star Food Mart

(iii) Is the “BUY ONE GET ONE” deal at Super Provisions the same as “50% off” deal?
Answer:
Yes