Class 8

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 6 Climatic Regions offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 6 Question Answer – Climatic Regions

Textbook Page no. 60.

See some characteristics of the Meditrranean clifinate is just opposite to Monsoon climate of our ountry. Cimpare the climate of two tyges.
Monsoon climate
1. Influenced by Monsoon wind
2. Summer hot and humid
3. Winter dry and cool
4. Rain fall occur due to wet Monsoon wiad
5. Monsoon wind blows seasonally.

Mediterranean Climate

1. Influenced by Trade wind.
2. Summer hot and cloudless.
3. Winter wet and ful of moisture.
4. Rainfall occur due to wet westerlies wind.
5. Seasonally Trade and Westerlies blows.

Textbook Page no. 64.

Question 1.
Write your own explanation ………………….. specific climatic regions.
Answer:
cause-effect relationship of physical and scio-economic environment.
Equatorial Climatic Region :
Heavy rainfall occurs through out the year for excessive temperature. For this reason evergreen forest has grown here. The inhabitants practise shifting cultivation. They also earn money through some industries, they are not so economically developed.

Monsoon climatic Reģion :
Four types of climates found here. Heavy rainfall occurs due to monsoon wind. Deciduous and cactus typed plants are grown here. Besides lion and tiger clephant, Rhino, wolf, bear are common animals of this region. The region is industrially developed for agriculture, densely populated and economically developed.

Mediterranean Climatic Region :
Almost 16 countries belong to this climatic region. For the temperature climate evergreen and deciduous plants grow here. This region is developed in agriculture, fruit based industry and export business. Film industry has been flourished. Economically prosperous region.

Tundra Climatic Region :
Extremely cold climate through out the year. The ice melts in summer. Short cool summer. Long cold winter. Mass, lichens grow. Rarely populated region. The main livelihood is hunting. Besides, exporting importing are other occupation. Presently, the region is gradually developing.
In your opinion, which climate. opinion and cite reasons.
Effect of Climate
Reason for development
Namc of the climatic region
In Miditerranean climatic region for the influence of modrate climate the summer is dry and the winter is wet. Snowfall is rare.

Reason for Backword
Name of the climatic region
In equatorial region hot summer is experienced through out the year and annual temperatures is less. Rainfall abundant.

Other reason
Economically developed. Agriculture and fruit based industries are the main livelihood of the people.
Unhealthy climate, dense forest, poisonous insects, malaria. black fever etc. are the hindrance of the development.

Class 8 Geography Chapter 6 Question Answer West Bengal Board – Climatic Regions

Multiple Choice Questions & Answers : (1 mark for each question)

Question 1.
In equatorial region the-
i) days one longer nights are shorter
ii) days are shorter nights are longer
iii) days and nights are almost equal
Answer:
iii) days and nights are almost equal

Question 2.
In equateral region nights are called –
i) Tropical summer
ii) Tropical winter
iii) Tropical autumn
Answer:
ii) Torpical winter.

Question 3.
In equaterial region in a year number of rainy days are-
i) 100-200
ii) 200-400
iii) 250-300
iv) 200-300
it Answer: 250-300

Question 4.
In equaterical region grows-
i) Brazil nut
ii) wal nut
iii) ground nut
Answer:
i) Brazil nut.

Question 5.
Brazilian rainforests in 2 sq K m can have up to-
i) 100 species of trees
ii) 200 species of trees
iii) 300 species of trees
iv) 400 species of trees
Answer:
iii) 300 species of trees

Question 6.
The inhabitants of Amazon basin are-
i) Pygmies
ii) Senuangs
iii) Red Indians
Answer:
iii) Red Indians.

Question 7.
The inhabitants of South-East Asia are-
i) Semangs
ii) Pigmies
iii) Red Indians
Answer:
i) Semangs.

Question 8.
In monsoon climatic region belongs to-
i) Amazon Basin
ii) Queensland
iii) Syria
iv) Libya
Answer:
ii) Queensland.

Question 9.
The average rainfall in monsoon climetic region is-
i) 100-200 cm
ii) 300-400 cm
iii) 150-250 cm
iv) 200-300 cm
Answer:
iv) 200-300 cm.

Question 10.
In monsoon climetic region which forest is foand-
i) mangrove forest
ii) grassland
iii) coniferous
Answer:
i) mangrove forest

Question 11.
At the coastal areas in monsoon climetic region the animal is found-
i) whale
ii) sherk
iii) Crocodile
Answer:
iii) Crocodile.

Question 12.
The main industry of monsoon region is-
i) iron and steel
ii) silk
iii) jute
iv) paper
Answer:
i) iron and steel

Question 13.
The influence of Mediterrancan climate is found in-
i) 10 countries
ii) 14 countries
iii) 15 countries
iv) 16 countries
Answer:
iv) 16 countries

Question 14.
The average rainfall in Mediterranean climetic region is –
i) 25-150 cm
ii) 100-200 cm
iii) 200-300 cm
Answer:
i) 25-150 cm.

Question 15.
The other name of Mediterranean climetic region is-
i) country of summer rainfall
ii) country of winter rainfall
iii) country of autumn rainfall
Answer:
ii) country of winter rainfall

Question 16.
The most famous fruit of Mediterranean climatic region is
i) olive
ii) mango
iii) orange
iv) straberry
Answer:
i) olive.

Question 17.
The most common cattle of Mediterranean climatic region is-
i) cow
ii) deer
iii) camel
iv) horse
Answer:
iii) camel.

Question 18.
The major industry of Mediterranean region is-
i) jute
ii) silk
iii) handloom
iv) iron
Answer:
ii) silk.

Question 19.
Italy in Mediterranean region is famous for-
i) iron
ii) mineral oil
iii) marble
iv) gold
Answer:
iii) marble.

Question 20.
Olive oil is obtained from-
i) olive
ii) grapes
iii) apple
iv) cherry
Answer:
i) olive.

Question 21.
The best film industry is developed in-
i) Rome
ii) Egypt
iii) Paris
iv) California
Answer:
iv) California.

Question 22.
Tundra region is named after-
i) Tundra tree
ii) Tundra bird
iii) one type of algae
Answer:
iii) one type of algae

Question 23.
Tundra climate is found in a very small part of-
i) northern part of Eurasia
ii) southerm part of Eurasia
iii) middle of Eurasia
Answer:
i) northern part of Eurasia

Question 24.
Virkhayansk is located at-
i) northern hemisphere
ii) equatorial region
iii) southern hemisphere
Answer:
i) Northern hemisphere.

Question 25.
In the land mass of Tundra region is found-
i) camel
ii) tiger
iii) horse
iv) sledge dog
Answer:
iv) sledge dog

Question 26.
In coastal region of Tundra region the animals found-
i) seal-whale-walrus
ii) seal-whale-crocodile
iii) seal-whale-starfish are found
Answer:
i) seai-whale-walrus

Question 27.
The inhabitants of the Northern part of Alaska is-4
i) Eskimos
ii) Fin
iii) Lapps
Answer:
i) Eskimos.

Question 28.
The inhabitants of Syberia in Eurasia is-
i) Samoyeds
ii) Eskimos
iii) Red Indians
iv) Lapps
Answer:
i) Satmoyeds.

Question 29.
In Tundra region animal is found-
i) wolf ,
ii) Polar beer
iii) Lion
iv) Tiger
Answer:
ii) Polar beer.

Question 30.
The food of the inhabitants of polar region-
i) milk and biscuits
ii) milk and strawberry
iii) milk and berry
Answer:
iii) milk and berry

Question 31.
The one of the major experting goods of Tundra region is-
i) tea
ii) tobaceo
iii) meat
iv) fleece
Answer:
iv) fleece

Question 32.
As the means of transportation in water the inhabitants of Tundra region use-
i) bajra
ii) launch
iii) kayak
Answer:
iii) kayak

Fill in the blanks : (1 mark for cach question)

1. Africa’s ______ river basin belongs to equatorial region.
2. Middle America’s Panama, ______ parts of climetic regien. islands experience equatorial
3. Through out the year worm summer exists resulting annual temperature range of only _______.
4. In equaterial region heavy ______ rainfall occurs.
5 . In the evening 3 or 4 pm the _______ louds cover the sky.
6. Equatorial climatic zone is influenced by ________ zone.
7. The tropical forest in Brasil’s Amazon river basin is called _______.
8. _____ tree is mostly found in equatorial climatic region.
9. ______ lives in the zaireh basin of equatorial region.
10. Pygmies, Red IndiAnswer:Semangs are gathering and ______ tribes.
11. Main plantation crops in equatorial clinatic region are cocoa, banana ______.
12. In equatorial region rubbar is produced in _____, Java – of Sourth-East Asia.
13. Cocoa and palm are cultivated in ______.
14. Sugarcane and ______ are cultivates in West Indies.
15. Mineral oil and are found abundantly in Sumantra, Java and
16. The Arbian word ‘Mousim’ means ______.
17. In Asia besides India monsoon climate is found in ______, _______
18. Due to ______ snowfall occurs in North-West India and some part of _____.
19. South-West monsson wind from Arabian sea and _____ causes heavy rainfall in Indian subcontinent.
20. For whimsical nature of _______ flood and droughts occur annualy.
21. Formation of depression in the Bay of Bengal causes ______ and _____.
22. In the monsoon climate dense _______ forests are found.
23. The places where the annual rainfall is more than 200 cm the forest like____ sishu garjan are grown in even dry season.
24. The places where the rainfall is 100-200 cm the forest of sal, teak, sisam ____, – mango, jackfruit are found.
25. ______ of Gir forest in Gujarat and of Sundarban is famous.
26. The landform of monsoon climate region is _______.
27. The Mediterrancan climatic region is found in – of North America.
28. ______ Libya, Algeria. Tunisia of Africa are influenced by Mediterranean climate.
29. Mediterranean climatic region is called as –
30. During summer high pressure belt is situated in the ______ region.
31. ______ is one of the main trees of Mediterranean region.
32. The main crop of Mediterranean region is _______.
34. Mediterranean region is called _______.
35. _______ and _______ are found in Italy of Mediterranean region.
36. _______ is found in Spain.
37. _______ from grapes is manufactured in France.
38. _______ of California is famous for film industry.
39. _______ of Portugal is one of a main port.
40. _______ of Australia is a fomous port.
41. _______ of America belong to Tundra region.
42. Some part of _______ in Southern hemisphere belongs to Tundra climatic region.
43. In Tundra climatic region rainfall is _____.
44. _____ and ______ flower bloom in Tundra region.
45. The people of Tundra region live in house made of ice or ______.
46. The people of Tundra region cultivate by using latest technology by ______.
47. _____ and _____ are the common phenomena of Tundra region.
48. In the northern Norway at _______ port sun remains visible at midnight.
Answer:
1. Congo
2. Coastarica, Caribbean
3. 2°C
4. Conventional
5. Cumulo-bumboo
6. Inter Tropical convergence
7. Enohona
8. Sinchona
9. Pygmies
10. hunting
11. palm
12. Malay Sumatra
13. Guinea Coast
14. Banana
15. Natural gas. Borneo
16. Season
17. Vietnam, Taiwan
18. Westerlies, Pakistan
19. Bay of Bengal
20. monsoon,
21. Thunder storm, rainfall
22. Evergreen
23. Mehogony,
24. palash, sirish, mahua
25. Lion, tiger
26. plain.
27. California
28. Egypt, Morocco
29. Country of winter rainfall
30. Mediterranean
31. Olive
32. Wheat
33. Silk
34. Basket of fruits
35. Marble and sulphur
36. Iron
37. Wine
38. Holywood
39. Lisbon
40. Adelaide
41. Canada
42. Antarctica
43. 20-30 cm.
44. Mass, Lichen
45. Igloo
46. greenhouse
47. Snowfall, snowdust
48. Hammerfest

State whether True or False : (1 mark for each question)

1. Throughout the year intence heat and heavy rainfall occur near equator.
2. In Equatorial climatic region days and nights are almost equal throughout the year.
3. Palm, cocoa and cinchona are main trees in the Selva.
4. Rubber is the main plantation crop in Malay.
5. Somalia and Madagascar are not influenced by monsoon climate.
6. North-East monsoon wind does not cause rainfall all over India.
7. Monsoon climatic region is world famous for rice cultivation.
8. Most of the roads are rough in monsoon climatic region.
9. Mild temperate climate throughout the year is the main characteristics of mediterrancan region.
10. Olive trees are seen in maximum number in mediterranean region.
11. Rome and Naoles in France are the main industrial centres.
12. Monsoon wind flows regularly throughout the year.
13. In Tundra region winters are long and severe.
14. After two months of spring summer comes in Tundra region.
15. The tundra is sparsely populated duc to adverse climate.
16. In coastal region of Tundra seal, whale, walrus are found.
17. There are 100-150 rainy days in a year in equatorial climatic region.
18. The Amazon basin was cosnected to the rest of the world by the TransAmazon Highway in 1970.
19. Monsoon climatic region is thickly populated region of the world.
20. In temperate climate region maize is the main crop.
21. Temperate climate region is rich in mineral resources.
22. Round shaped house Igloo is made of ice.
Answer:
1. true
2. true
3. false
4. true
5. false
6. true
7. true
8. false
9. true
10. true
11. false
12. false
13. true
14. false
15. true
16. true
17. false
18. true
19. true
20. false
21. false
22. true

Match the following : (1 mark for each question)

Match the column A with column B.

Column A	Column B
a) Samoyeds live	i) are evergreen trees
b) Inhabitants of Tundra climatic region	ii) is called Busket of fruits
c) Snowfall and snowstorm are common	iii) $10^{\circ}$ to $30^{\circ}$ latitudes in both hemisphere
d) Eucalyptus and rosewood	iv) trees in Congo
e) Temperate climate region	v) is thickly populated
f) Cold summer, wet winter are main	vi) in Eurasia
g) Monsoon climate region	vii) import tea, coffee, tobaceo
h) Monsoon climate is found from	viii) in Equatorial climatic region
i) Cocoa and cinchona are dominant	ix) in Tundra climatic region
j) The humidity always remains high	x) characteristies of temperate climate

Answer:
a) Samoyeds live in Eurasia.
b) Inhabitants of Tundra climatic region import tea, coffee,”tobacco.
c) Snowfall and snowstorm are common in Tundra climatic region.
d) Eucalyptus and rosewood are evergreen trees.
e) Temperate climate region is called Busket of fruits.
f) Cold summer, wet winter are main characteristics of temperate climate.
g) Monsoon climate region is thickly populated.
h) Monsoon climate is found from 10° to 30° latitudes in both hemisphere.
i) Cocoa and cinchona are dominant trees in Congo.
j) The humidity always remains high in Equatorial climatic region.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
Which region is located as equatorial region?
Answer:
The region between 5°-10° north and south latitude is located as equatorial region.

Question 2.
Which part of India belong to equatorial region?
Answer:
The south west part of India belong to equatorial region.

Question 3.
Which part of South America belong to equatorial region?
Answer:
The amazon river basin of South America belong to equatorial region.

Question 4.
Which part of Middle America belong to equatorial region?
Answer:
Middle american’s Panama. Coasterica, part of Caribbean Islands.

Question 5.
What is known as the night of the equatorial region?
Answer:
It is known as “winters of the tropies”.

Question 6.
What is known the equatorial forest?
Answer:
Equatorial forest is known as Evergreen forest.

Question 7.
Which type of rainfall occurs in equatorial region?
Answer:
Convectional rainfall.

Question 8.
What is known as the tropical forest of Brazil?
Answer:
Selva.

Question 9.
How many species of trees found in the rain-forest of Brazil in 2 sq Km area?
Answer:
300 species of trees in 2 sq Km area in Brazilian rainforest.

Question 10.
Name the inhabitant of Zaire basin.
Answer:
Pigmies live in Zaire Basin.

Question 11.
Which type of inhabitants found in upper Amazon basin?
Answer:
Red Indians.

Question 12.
Which type of people found in South-East Asia?
Answer:
Semangs are found in South-East Asia.

Question 13.
Which type of agriculture is followed in equatorial region?
Answer:
Shifting agriculture is followed in equatorial region.

Question 14.
What are cultivated in Gunea Coast of Africa?
Answer:
Cocoa and palm are cultivated in Gunea Coast of Africa.

Question 15.
When was Trans-Amazon highway constructed?
Answer:
Trans-Amazon highway was constructed in 1970.

Question 16.
What are the causes of the hinderace of economical development in equatorial region?
Answer:
Unhealthy environment, dense forest, poisonous insect, maleria etc.

Question 17.
What is the meaning of the word ‘monsoon’?
Answer:
The word monsoon means season.

Question 18.
Which region of East Africa belong to monsoon climetic region?
Answer:
Somalia, Madagascar of East Africa.

Question 19.
How many types of season found in monsoon climatic region?
Answer:
4 types of season are found in monsoon climatic region.

Question 20.
Which part of Australia experience ‘monsoon’ climate?
Answer:
Queensland Province of Australia.

Question 21.
Which countries of Asia belong to monsoon climatic region?
Answer:
India, Pakistan, Bangladesh, Srilanka, Myanmar. Thailand, Vietnam, Kamptichlia, South Chitha, Philippines etc.

Question 22.
What is the average temperature of monsoon climatic region?
Answer:
The average temperature is 25° C.

Question 23.
What is the annual rainfall of monsoon climatic region?
Answer:
Annual rainfall is 200-300 cm.

Question 24.
What is the annual rainfall of Mawsynran?
Answer:
Annual rainfall is nifore than m0re than 1200 cm.

Question 25.
Which type of vegetation found in Monsoon climatic region?
Answer:
Dense evergreen forest is found.

Question 26.
Where is the evergreen forest found in monsoon climatic region?
Answer:
Evergreen forest is found the places where the annual rainfall is 200 cm.

Question 27.
Where is mangrove forest is found in monsoon climatic region?
Answer:
The mangrove forest is found in Coastal area of monsoon climatic region.

Question 28.
Name the animals of monsoon climatic region.
Answer:
The animals are elephant, rhinocerous, cheeta, deer, wolf, monkey, fox etc.

Question 29.
Name the minerals of monsoon climatic region.
Answer:
The minerals, like coal, iron, copper, man anese, bauxite, mineral oil are found in monsoon climatic region.

Question 30.
Name the crops of monsoon climatic region.
Answer:
The main crops are rice, jute, wheat, sugarcane, cotton, oil seed, tea, coffee etc.

Question 31.
Name the fruits of monsoon climatic region.
Answer:
Fruits are mango, cherry, jackfruit, bannana, pineapple etc.

Question 32.
Name the minerals of equatorial region.
Answer:
The minerals are tin in malaya, mineral oil and natural gas in Sumarta, java and bornio.

Question 33.
What are the main industry of monsoon climatic region?
Answer:
Jute industry, cotton textile industry, tea industry etc.

Question 34.
How is the communication system in monsoon climatic region.
Answer:
The communication system is very good. The railway, roadway and airway is highly developed.

Question 35.
What are the main cities of monsoon climatic region.
Answer:
Delhi, Kolkata, Chennai, Sanghai, Dhaka, Yangoon, Bangkok etc.

Question 36.
Name a country of South America in mediterranean climatic region.
Answer:
Chilli of South America is in mediterranean climatic region

Question 37.
Name some Europian countries lie in Mediterranean climatic region.
Answer:
France, Italy, Spain, Greece, Portugal, Albenia, Yagoslava.

Question 38.
Name some Asian countries lie in Mediterrancan climetic region.
Answer:
Turkey, Israel, Syria, lebanon.

Question 39.
Name some African countries lie in Mediterranean climatic region.
Answer:
Egypt, Morocco, Libya, Algeria, Tunisia etc.

Question 40.
Name some countries of the world where Mediterranean climate is found.
Answer:
California of North America, Chile of South America, Cape Town of South Africa,
South West and South-Eastern part of Australia.

Question 41.
What are the main features of Meditiranean climate?
Answer:
Mild temperature through out the year, dry summer and wet winter.

Question 42.
What is the other name of Mediterranean climatic region?
Answer:
The other name is ‘country of winter rainfall’.

Question 43.
What are the natural vegetation of Mediterranean climatic region?
Answer:
Evergreen forest with thick leaves and hard stem.

Question 44.
Name some type of vegetation found in Meditirranean climatic region.
Answer:
Coneferous vegetation, Evergreen vegetation and shurb type vegetation.

Question 45.
Name some coniferous trees of Mediterranean climatic region.
Answer:
Pine, Fir, Cedar.

Question 46.
Name some evergreen trees of Mediterennean climatic region.
Answer:
Oak, Cork, Eucalyptus, Rosewood.

Question 47.
What are the shrub type vegetation of Mediterranean climatic region?
Answer:
Maple, Laurel, Rasemery, Lavender.

Question 48.
Name one of the main trees of Mediterranean climatic region.
Answer:
Olive.

Question 49.
Name some animals of Mediterranean climatic region.
Answer:
Donkey, Sheep, Goat, Mule.

Question 50.
Name some crops of Mediterranean climatic region.
Answer:
Maize, barley, rice, cotton, tobacco.

Question 51.
What fruits are found in Mediterranean climatic region?
Answer:
Grapes, olive, pear, apple, orange, walnut, pianult, pulm, fig etc.

Question 52.
What is the Mediterranean climatic region called for the production of fruits?
Answer:
It is called as ‘Basket of fruits’.

Question 53.
Name the minerals of Mediterranean climatic region.
Answer:
Mineral oil in California, Bankette in France, Marble in Italy, Iran \& Spain.

Question 54.
What are the different occupation of the people of Mediterranean climatic region?
Answer:
Agriculture, orchard forming and archard based,industry, trade and commerce.

Question 55.
What are the different industry of Mediterranean climatic region?
Answer:
Wine making in Italy and France and processing from olives, processing fruit products.

Question 56.
Name a special industry of Mediterranean climatic region.
Answer:
A special industry is famous film industry ‘Hollywood’ in California.

Question 57.
Name some main cities of Mediterranean climatic region.
Answer:
Los Angeles, San Francisco in California, Rome and Naples in Italy, Cape Town in south Africa, Adelaide in Australia, Lisbon in Portugal.

Question 58.
Why is Tundra region named as Tundra?
Answer:
From the name of an algae this region is named as Tundra.

Question 59.
Which countries in Europe belong to Tundra region?
Answer:
Norway, Sweeden, Finland, Narrow coast of Greenland.

Question 60.
Which countries in Asia belong to Tundra region?
Answer:
Siberia in Asia.

Question 61.
What are the climatic features of Tundra climatic region?
Answer:
Short cool summer and long severe cold winter.

Question 62.
What is the coldest place of Northern hemisphere?
Answer:
Verkhoyansk in Siberia.

Question 63.
Which place is called the ‘Land of Midnight Sun’?
Answer:
Hammerfest port in Norway.

Question 64.
What is the average temperature of Tundra region?
Answer:
Average temperature is 10° C.

Question 65.
Which type of vegetation grow in Tundra climatic region?
Answer:
Mosses, shrub type of Birch, Juniper, Alder grow here.

Question 66.
Which type of vegetation grows in the wetland of Tundra?
Answer:
Mosses, dichens, different types of colourful flowers bloom in the wetland of Tundra.

Question 67.
What animals are found in the landmass of Tundra region?
Answer:
Sledge dog, arctic fox, polar deer, caribou are found in Tundra regicn.

Question 68.
What are the animals found in the coastal region of Tundra region?
Answer:
Seal, whale, walrus and different types of fishes.

Question 69.
Name the inhabitants of Tundra region.
Answer:
Eskimos, Red Indians, Samoyeds, Yakut, Lapps etc.

Question 70.
Name the inhabitants of greenland.
Answer:
Eskimos, Red Indians.

Question 71.
Name the inhabitants of Siberia in Eurasea.
Answer:
Somoyeds, Yakuts.

Question 72.
Name the inhabitants of Finland.
Answer:
Fin.

Question 73.
What type of people live in Tundra region?
Answer:
Normodic type.

Question 74.
In which type of house the people of Tundra region live in winter?
Answer:
They live in a round shaped house called Egloo during winter.

Question 75.
Where do they live in summer when the ice is melted?
Answer:
In summer when the ice is melted they live in tent made of seal’s skin called tupics.

Question 76.
What is known as the tent?
Answer:
The tent is known as Tupics.

Question 77.
What do the people of Tundra region use for transportation?
Answer:
They use wheelles sledge and the boat Kyak made of seal’s skin for tranportation.

Question 78.
What are the garments of the people of Tundra region made up of?
Answer:
They use to skin of animals in making their clothes.

Question 79.
What do the people of Tundra region use to make weapons?
Answer:
They use bones of animals for making weapons.

Question 80.
What animals do the people of Tundra region hunt for food?
Answer:
Seal, beer, Reindeer, arctic fox and fishes from sea.

Question 81.
What are the favourite food of the people of Tundra region?
Answer:
Milk of reindeer and berry fruits.

Question 82.
Name the minerals found in Tundra region.
Answer:
Coal, iron ore, gold, mineral oil.

Question 83.
Where are gold and mineral oil found?
Answer:
Ukraine and Alaska.

Question 84.
Where is iron-ore found?
Answer:
Kiruna region.

Question 85.
Where is coal found?
Answer:
Pittsburrgh.

Question 86.
Name a railway of Tundra region.
Answer:
The railway connecting Murmansk part of Siberia to Saint Reters-burg.

Question 87.
Name a Highway of Tuntra region.
Answer:
Alaska highway.

Question 88.
What are the imported and exported good of Tundra?
Answer:
This region import tea coffee tobacco against fleece and feather of animals.

Long Questions & Answers : (3 marks for each question)

Question 1.
What is called ‘Burst of Monsoon’?
Answer:
When South-East Monsoon coming from Arabean sea branch and Bay of Bengal branch enter the Indian subcontinent and sudden and tremendous rainfall occurs. This is called Burst of Monsoon.

Question 2.
Mention the climatic characteristics of equatorial climatic region.
Answer:
The Sunrays fall perpendicular on this region through out the year. So this region experience extreme temperature. During the day temperature rises upto 38° C and at night it remain 20°-25° C. The difference between highest and lowest tange of temperature is more. Heavy rainfall occurs through out the year.

Question 3.
Write about natural vegetation of equatorial climatic region.
Answer:
In this region some or the other tree bears green leaves, flowers and fruits throughout the year. Hence, these forests are called evergreen forests. They are called Selva in the Amazon basin of brazil. Rubber, rosewood, Brazil nut, iron wood and bamboo are found in the selva. Mahogany, rubber, palm, cocoa and cinchona are the dominant trees in the Congo and Zaire basins. In southeast Asia the equatorial forests consist of ablus, sal, teak, rubber trees. In the coastal areas coconut and palm trees are common.

Question 4.
Write about animals of equatorial climatic region.
Ans.
Here birds and animals that can climb trees are dominant. Because here the forest is dense and the floor is covered with undergrowth. Monkeys, cl.impanzees, gorillas, orangutans, snakes, birds, insects and pests are found here. On land elephants, deer, rhinoceros and in water crocodiles and hippopotamus are found.

Question 5.
Write about the inhabitants of equatorial climatic region.
Answer:
Due to hot humid climate, unhygienic conditions and wild natural environment here human settlements are scanty. Equatorial climatic regions of south-east Asia are more inhabited than the Zaire ar. Amazon bisins. Main inhabitants of this region are Pygmies of Zaire basin, Red Indians of upper A mazns basin, Semangs of south-east Asia.

Question 6.
Write about farming of the inhabitants of equatorial climatic region.
Answer:
Methods of shifting cultivation are being practiced in the forest fringes to grow corns, turnip, banana, yum. After establishing colonies by Europian traders, now the inhabitants practice piantation farming. Among them rubber in Malay, Java and Sumatra of south-east Asia, sugarcane and banana in West Indies, cocoa and palm in the Guinea coast are mentionable.

Question 7.
Write about minerals and industries of equatorial climatic region.
Answer:
Minerals available in this region are – tin in Malaya, natural gas and petroleum in Sumatra, Java and Borneo. Want of raw materials has prevented the growth of heavy industries in this region. Based on local agro-based. forest-based and mineral-based raw materials some industries have emerged.

Question 8.
Mention the location of monsoon climatic region.
Answer:
Monsoon climate is found from 10°-30^{\circ \prime latitudes in both hemispheres. In Asia India, Bangladesh, Pakistan, Mayanmar, Srilanka, Vietnam, Kampuchea, Thailand, Taiwan, South China and some psrts of Philippines are under the influence of monsoon climate. Moreover, Somalia and Madagascar of East Africa, Queensland province of Australia are infuenced by monsoon climate.

Question 9.
Mention the climatic characteristics of monsoon climatic region.
Answer:
Four seasons are noticed in monsoon climate. They are – a) Winter (NovemberJanuary), b) Pre monsoon summer (March-May), c) Monsoon Rainy Season (June-September), d) Autumn (September-October). In winter North-East monsoon wind blows. It does not cause rainfall in India. But Srilanka, Coromandal coast, Andaman and Nicobar Island gets more rainfall. Average temperature of Summer is 30° C. Intense heat creates low pressure. In Monsoon rainy season water vapour in the air is maximum. Sudden and tremendous rainfall occurs. in Autumn cold weather prevails. Formation of deep depression in the Bay of Bengal causes thunderstorm and rainfall.

Question 10.
Write about settlement, agriculture, industry of monsoon climatic region.
Answer:
This region is the leading producer of rice. Besides wheat, sugarcane, cotton, oil seed and different types of fruits like mango, jumun, jack gruit, lichi, banana, pine apple are grown here. The minerals like coal, iron, copper, manganese, bauxite, mineral oil are found in this region. Jute

industry, cotton industry, tea industry, iron and steel industry are the heavy industries of this region. The communication and transport system through railways, waterways, roadways are highly developed. The popular and developed cities like Delhi. Kolkata, Mumbai are flourished in this region. Rapid economic prosperity is the feature of this region.

Question 11.
Write about location of Mediterranean climatic region.
Answer:
This climatic region lies in hot temperate zone. This type of climate is found in the Western part of the continents lie between 30°-40^{\circ latitude of both hemisphere. France. Italy, Spain, Greece, Portugal, Albania, former Yogoslavia of Europe. Turkey Israel, Syria, Lebanon of Asia; Egypt, Morocco, Libya, Algirea, Tunisia of Africa experience this type of climate. Also California of North America, Chili of South America, Capetown of South Africa, South. West and South Eastern part of Australia belong to this climatic region.

Question 12.
Write about animal rearing and agriculture of Mediterranean climatic region.
Answer:Here prevails rainless dry summer and wet winter. Hence donkey; sheep, goat, mule are reared here. Near hot deserts hen, camel are reared. This region is developed in agriculture. Wheat is the main crop. Moreover rice, maize, cotton, barley and tobacco is produced here. Due to bright and sunny weather grapes, apple, pears, olive, or ange, peach, walnut, peanuts, palm, sweeet fig and different types of citrus fruits are produced here. This region is called ‘Busket of fruits’.

Question 13.
Write about minerals and industry of Mediterranean climatic region.
Answer:
This region is not rich in mineral wealth. Mineral wealth in California, bauxite in France, marble and sulphur in Italy, iron in Spain are found here. Agriculture. orchard farming and orchard based industry, trade and commerce are main occupation here. Grapes are used in wine making in Italy and France. Oil producing from olives is a main industry in this region. Dry fruit, processed food products and flour industry is also mentionable. World famous filn industry Hollywood in California is located in this region.

Question 14.
Write about location of Tundra climatic region.
Answer:
Near the Arctic circle northern part of Canada in North America, Alaska, Northern parts of Eurasia, Norway, Sweden, Finland, coast of Greenland and Siberia in Asia are under the influence of tundra climate. This climate is also found in very small parts along the coast of Antarctica in southern hemisphere.

Question 15.
Describe about the winter climate of Tundra climatic region.
Answer:
At this region winters are long and severe cold. Winter lasts 8-9 months. At that time temperature falls 20° C-40° C. In Verkhoyansk of Siberia (coldest place of Northern hemisphere) average temperature of January remains -50.6° C. Due to severe cold entire region is covered by snow. Here snowfall and snowstorm are very common phenomena. Sun remains almost invisible in sky at that time. In continuous dark night sometimes for 2-3 hours Aurora Borealis and Aurora Australis are seen.

Question 16.
Describe about the summer climate of Tundra climatic region.
Answer:
After two weeks of spring summer comes in Tundra region. It lasts for 2-3 months. This time average temperature remains 10° C. Sunset exists for a very short duration. Though sunrays exist 22-23 hours due to slanting rays. In the northern Norway at Hammerfest port and nearer ares remain visible at midnight. For this, this region is called ‘Land of Midnight Sun’. During summer the sky remains covered by fog.

Question 17.
Describe natural vegetation and animal life of Tundra climatic region.
Answer:
In Tundra climatic region as most of the times of the year temperature remains below freezing point, trees cannot grow. Mosses, shrub, birch, juniper, alder grow in summer when ice melts: In summer ground surface remains frozen. Wet land is formed due to accumulation of rain water on the ground surface. Mosses, lichens, different types of flowers bloom in the wetland. In the landmass of Tundra sledge dog, arctic fox, polar bear, caribou are seen. In coastal region seal, whale, walrus and different types of fishes are found.

Question 18.
Describe inhabitant’s lifestyle of Tundra climatic region.
Answer:
In Tundra region due to adverse climate, hardy lifestyle this area is sparsely populated. Here inhabitants set up their lives fighting with nature. Eskimos, Red Indians.Samoyeds, Yakutus, Lappas, Fin people live here. For severe cold agriculture is not possible here. The inhabitants roam from one place to another place. During winter they live in a round shaped house Igloo. It is made of ice. In summer when ice melts away they make tents tupics made of seal’s skin. For transportation they use wheelless sledges and the boat kayak made of seal’s skin. They use the skin of animals in making their clothes and bones for weapons. They hunt seal, bear, reindeer. arctic fox and catch fishes from sea for livelihood. Milk of reindeer and berry fruits are their favourite food.

Question 19.
Mention the recent changes in Tundra climatic region.
Answer:
Recently some mining areas are found here. Coal from Pittsburgh, iron-ore form Kiruna, gold and mineral oil form Alaska and Ukraine. So, a few industries have developed here. Connection with outerworld has increased through railways and water ways. Railway communication from Murmansk port of Siberia to Saint Petersburg has been established. Alaska highway of North America has connected Tundra region with the other parts. In some parts agriculture is done with the latest technology by greenhouse. Inhabitants of this region import tea, coffee, tobacco against fleece and feather of animal. Nowadays inhabitants are habituated with modern lifestyle.

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 5 Cloud and Rain offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 5 Question Answer – Cloud and Rain

Textbook Page no. 47.

Question 1.
By which process does the air heat up in case of convectional rainfall?
Answer:
The sun rays fall vertically on those regions where convectional rainfall occurs and for this reason the air hots up by the process of covection.

Question 2.
Why do ever green forests grow in the equatorial region?
Answer:
Ever green forests grow in the equatorial region because the sun rays fall vertically here through out the year. As the water mass is more in this region the amount of water vapour in air is more. As the result convectional rainfail occurs and evergreen forests have grown.

Question 3.
Name two countries that experience convectional rainfall through out the year.
Answer:
The two countries that experience convectional rainfall through out year are India and Bangladesh.

Textbook Page no. 4

Question 1.
Why does a barefoeted morning walk on the grass make your feet wet in winter?
Answer:
A barefooted morning walk on the grass make our feet wet in winter because dew drops accumulate on the grass.

Question 2.
why is less dew observed in dry region?
Answer:
In the dry region as the cold wind in the layer of atmosphere is less the water vapour near the earth surface become comparetively less cool and condensed. So less dew is observed in dry cegion.

Question 3.
Why is fog mainly seen in winter and on water bodies?
Answer:
In winter the amount of water vapour is more mainly on the water bodies. These water vapour condenses around the dust particle to form the fog.

Question 4.
What type of rainfall is generally observed in our country in the monsoon?
Answer:
In our country generally cyelonic rainfall occurs in monsoon.

Question 5.
why is the amount of water vapour are different in different areas?
Answer:
The temperature of air is different in different areas. Some areas have cool climate some have moderate. Some areas are surrounded by the mountains. The Sun rays fall vertically in some places, whereas squinting in other places. So the amount of water vapour are different in different areas.

Class 8 Geography Chapter 5 Question Answer West Bengal Board – Cloud and Rain

Multiple Choice Questions & Answers : (1 mark for each question)

Question 1.
The word ‘oros’ means-
i) rain
ii) rock
iii) mountain
iv) river
Answer:
iii) mountain

Question 2.
The name of the cyclone of Bay of Bengal is-
i) cyclone
ii) Aila
iii) Typhoon
Answer:
i) cyclone

Question 3.
The cyclone that occured in 2009 is-
i) cyclone
ii) Aila
iii) Phailin
Answer:
Aila.

Question 4.
Combined form of water droplets and ice particles is called-
i) sleet
ii) cloud
iii) water vapour
Answer:
sleet.

Question 5 .
The distance between Cherrapunji and Shilong is-
i) 85 km.
ii) 56 .km.
iii) 58 km.
iv) 50 km.
Answer:
ii) 56 km.

Question 6.
The average maximum height of low cloud is-
i) 5,000 ft.
ii) 5,600 ft.
iii) 6,000 ft.
iv) 6,500 ft.
Answer:
iv) 6,500 ft.

Question 7.
The cloud with fibrous appearance is-
i) cumulus
ii) cirrocumulus
iii) cirrus
iv) altostratus
Answer:
iv) altostratus.

Question 8.
Mackerel sky is called when the sky is covered in-
i) cirrocumulus cloud
ii) cirrus cloud
iii) Altostratus cloud
iv) stratocumulus cloud
Answer:
i) cirrocumulus cloud

Question 9.
A vertical cloud is-
i) cumulus
ii) cirrus
iii) stratus
Answer:
i) cumulus

Question 10.
cumulonimbus looks like-
i) wooly
ii) dome
iii) light film
Answer:
ii) dome

Question 11.
From cumulonimbus cloud occurs-
i) Drizzle
ii) hailstorm
iii) snow fall
Answer:
ii) hailstorm

Question 12.
Cloud is formed in the laye –
i) Atmosphere
ii) Magnetosphere
iii) Troposphere
Answer:
iii) Troposphere

Question 13.
Which is not precipitation-
i) hailstorm
ii) rain
iii) Fog
Answer:
iii) Fog.

Question 14.
The instrument for measuring rain is-
i) animometer
ii) rain gauge
iii) barometer
Answer:
ii) rain gauge

Question 15.
Tiny droplets foating around like smoke is called-
i) fog
ii) dew
iii) smog
Answer:
i) fog

Question 16.
The diameter of tiny water droplets is-
i) 0.06 mm.
ii) 0.00 mm.
iii) 0.05 mm.
iv) 0.2) mm.
Answer:
iii) 0.05 mm.

Question 17.
From stratus cloud occurs-
i) Drizzle
ii) thunderstorm
iii) hailstorm
Answer:
i) Drizzle

Question 18.
Cyclone on East China is known as-
i) hurricane
ii) typhoon
ii) cyclone
Answer:
ii) typhoon

Question 19.
Cyclone is forward in both hemisphere in the latitude of-
i) 20°-25°
ii) 25°-30°
iii) 15°-25°
iv) 5°-20°
Answer:
iv) 5°-20°

Question 20.
The average annual rainfall of Cherrapunji is-
i) 2,250 mm.
ii) 11,777 mm.
iii) 2,207 mm.
iv) 10,767 mm.
Answer:
ii) 11,777 mm.

Question 21.
The imaginary line joining place with some average amount of precipitation is called on-
i) isotherm
ii) isohyet
iii) isopress
Answer:
ii) isohyet.

Question 22.
Which of the wids join together in cyslonic rainfall-
i) North-East and South-East trade wind
ii) North-South and South-West trade wind
iii) South-West trade wind
Answer:
i) North-East and South-East trade wind.

Fill in the blanks : (1 mark for each question)

1. The cloud that forms thin white film is called _______.
2. Cirrocumulus cloud make the sky iook like the _______ body of _______ fish.
3. The average height of medium clouds is ________ fit te ________ ft.
4. _______ cloud generally forecasts lingering rain.
5. _______ cloud is a layered cloud.
6. The other name of strotscumulus cloud is _________.
7. Stratus cloud is white to coloured and covered the entire sky like ____.
8. Accumulation of stratus cloud causes a great problem for _______ and ______.
9. Stratus cloud can sometimes cause a _________.
10. _______ cloud indicates bad weather.
11. The top surface of cumulus cloud is white, irregular and undulating like a while the bottom is black and _________
12. Cumulonimbus may be grey or ______ and is somewhat ________.
13. Cumulonimbus has a great vertical extent of about __________ f f upward from the layer of air adjacent to the surface of the earth.
14. Cumulonimbus cloud causes violent ________ and torrential-
15. The other name of cumulonimbus cloud is _________.
16. The diameter of the water droplets in cloud is ________.
17. In the layer of __________ the cloud forms.
18. The changing of water into water vapour is __________.
19. The tempereature at which the air gets saturated is its ________.
20. The changes of water vapour into droplets is called ___________.
21. Water droplets descending from the atmosphere to the surface of the earth in the influence of ________ is called ___________.
22. Cloud is the collection of small ___________.
23. ___________ rainfall is restricted to a small areas.
24. The rainfall that occurs for gettting obstructed by the mountain is called ____________.
25. The slope of the mountain along which the wind descends is the _______ side.
26. The leeward slope is called _______ region.
27. The sunrays fall _________ on the equatorial region through out the year.
28. _________ is located in the Hills of Meghalaya.
29. The ________ rainfall that caused by a cyclone is called _______ Rainfall.
30. The __________ sea branch of the south-west monsoon wind strikes the Western Ghats and causes abundant on its western slope.
31. ‘Aila’ occured in _______.
33. A combined form of _________ and ice particles is called ___________.
34. _________ causes some damage to crops and weakly constructed structures.
35. Hailstorm are sometimes seen in West Bengal during _______ or _________.
36. In high mountain region ____ wind is cooled to a temperature below freezing point the water vapour is directly converted to _________.
Answer:
1. cirrostratus
2. scaled, mackerel
3. 6.500:20,000
4. Altostratus
5. Stratocumulus
6) Bumpy cloud
7. grey, fog
8. mountaineers. pilot
9. drizzles
10. Nimbostratus
11. cauliflower, flat
12. whitish grey, black, dome shaped
13. 12.000
14. Thunderstorm, rain
15. Thunder cloud
16. 0.02 mm
17. Troposphere
18. evaporation
19. dew point
20. condensation
21. gravitational pulI. precipitaion
22. droplets of water
23. convectional
24. orographic
25. beward
26. rain shadow
27. vertically
28. Cherrapunji, Khasi
29. cyclonic
30. Arabian, rainfall
31. 2009
32. Typhoon
33. water droplets, sleet
34. Hailstorm
35. spring. summer
36. moisture laden, ice.

State whether True or False : (1 mark for each question)

1. More dew is formed on cloudless nights.
2. A combined form of water droplets and ice particles is called sleet.
3. Generally tropical cyclones are formed betwween 0° and 5° parallels of latitude in both hemisphere.
4. Average annual rainfall in Cherrapunji is approximately 6,637 mm.
5. The change of water vapour into water droplets is called condensation.
6. Cirrocumulus indicates bad weather.
7. Stratocumulus is called Bumpy Clouds.
8. Cumulus cloud is called thunder cloud.
9. Evaporation is the change of water into water vapour.
10. The temperature at which air gets saturated is its condeirsitiom
11. When a mountain or any upland stands in the path of moisture ladden wind from the sea, the wind is blocked in its path and rises alon the slope of the natural barrier.
12. Ornographic rainfall is called convectional rainfall.
13. The top surface of cumulus cloud is irregular and undulating like a cauliflower.
14. Hailstorms can occur from cumulus cloud.
15. Convectional rainfall generally takes place in the afternoon or evening and is usually torrential and thunderous.
16. Nimbostratus cloud indicates bad weather.
Answer:
1. true
2. true
3. false
4. false
5. true
6. false
7. true
8. false
9. true
10. false
11. true
12. false
13. true
14. fale
15. true
16. true

Match the column A with column B.

Column A	Column B
a) Rainfall is the most familiar example	i) indicates fair weather
b) Cumulonimbus cloud may be	ii) different names at different locations
c) Cirrus cloud generally	iii) Rain Shadow Region
d) Cirrocumulus cloud is called	iv) to crops and weakely costructed structures
e) Blue sky can be seen	v) is called Cyclonic Rainfall
f) Leeward slope is known as the	vi) whitish grey or black
g) Fog can sometimes reduce	vii) of precipitation
h) Hailstorm cause some damage	viii) visibility to a afew metres
i) Tropical cyclones are known by	ix) through the gaps in Altostratus cloud
j) Rainfall caused by a cyclone	x) the Mackerel Sky

Answer:
a) Rainfall is the most familiar example of precipitation.
b) Cumulonimbus cloud may be whitish grey or black.
c) Cirrus cloud generally indicates fair weather.
d) Cirrocumulus cloud is called the Mackerel Sky.
e) Blue sky can be seen through the gaps in Altostratus cloud.
f) Leeward slope is known as the Rain Shadow Region.
g) Fog can sometimes reduce visibility to a afew metres.
h) Hailstorm cause some damage to crops and weakely costructed structures.
i) Tropical cyclones are known by different names at different locations.
i) Rainfall caused by a cyclone is called Cyclonic Rainfall.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
What is the height of the highest cloud?
Answer:
20,000 feet.

Question 2.
What is the name of white, light and feathery cloud?
Answer:
Cirrus cloud.

Question 3.
How does the cirrocumulus could look like?
Answer:
cotton wool type.

Question 4.
How does the Altostratus cloud look like?
Answer:
Grey to bluish in colour with fibrous appearance.

Question 5.
Name some clouds with medium height.
Answer:
Altostratus and Altocumulus.

Question 6.
What is the other name of Stratocumulus?
Answer:
The other name of Stratocumulus is Bumpy cloud.

Question 7.
From which cloud rainfall with violent thunderstorms occurs?
Answer:
cumulonimbus.

Question 8.
What is the other name of cumulonimbus?
Answer:
Thunder cloud.

Question 9.
How is the cloud formed?
Answer:
The water of the sea, pond, river is heated by the sunrays and turn into water vapour. Then it accumulates the dust particle to form cloud.

Question 10.
In which layer of earth the cloud is formed?
Answer:
The cloud is formed in Troposphere of air.

Question 11.
What is evaporation?
Answer:
The process by which water is turned into water vapour.

Question 12.
What is saturated air?
Answer:
When a specific quantity of air holds the maximum amount of water vapour that it can hold a specific temperature, it is said to be saturated.

Question 13.
What is the diameter of general droplets of cloud?
Answer:
0.02 mm.

Question 14.
What are the different types of rainfall?
Answer:
There are the three types of rainfall-i) Convectional, ii) Orographic, iii) Cyclonic

Question 15.
What is windward side?
Answer:
The slope along which wind ascends and causes rainfall is the windward slope.

Question 16.
What is leeward slope?
Answer:
The slope along which the wind descends is called the leeward slope.

Question 17.
Name a ‘Rain shadow Region’.
Answer:
Meghalaya plateau.

Question 18.
What is the distance between Cherrapunji and Shillong?
Answer:
The distance between Cherrapunji and Shillong is 56 Km.

Question 19.
What is the average annual rainfall of Cherrapunji?
Answer:
11.777 mm.

Question 20.
What is the average annual rainfall of Shillong?
Answer:
2,207 mm.

Question 21.
What is the name of the cyclone of 2009 ?
Answer:
Aila.

Question 22.
What is the name of the cyclone of 2013 ?
Answer:
Pheilin.

Question 23.
What is the name of the cyclone found in the Bay of Bengal?
Answer:
Cyclone.

Question 24.
What is called the cyclone of Caribean sea?
Answer:
Hurricane.

Question 25.
What is ‘sleet’?
Answer:
A combined form of water droplets and ice particles is called sleet.

Question 26.
When is the rainfall occured in West Bengal?
Answer:
Rainfall is occured in West Bengal in rainy season.

Question 27.
Which instrument is used for measuring rainfall?
Answer:
Rain gauge.

Short Questions & Answers : (2 marks for each question)

Question 1.
What is fog?
Answer:
When water vapour in the air near the carth”s surface condenses around dust particles in it and forms tiny droplets of water, they float around and appear like smoke. This is called fog.

Question 2.
What does the term ‘Orographic’ mean?
Answer:
‘Oros’ means mountain. The word ‘Orographic’ derives from the fact that a mountain or any other upland stands in the way of wind and helps to cause rainfall.

Question 3.
What is ‘Hailstorm’?
Answer:
For the ascending air current the water particles sometimes rise high and getting cooled turn into little particles of ice. When more droplets of water gather around the ice particles their volume expands and fall with the rain. This is called ‘Hailstorm”.

Question 4.
What is convectional rainfall?
Answer:
The amount of evaporation is more in those arears where the sunray falls vertically through out the year and the water mass is more than landmass. The water vapours condense into tiny droplets and accumulate around the dust particle to form cloud. The rainfall that occur from this cloud is called the convectional rainfall.

Question 5.
What is Orographic rainfall?
Answer:
The wet moisture laden wind from the sea gets obstructed, goes high up. As it goes high it becomes cool and expanded. Then it condenses and causes rainfall. This is called Orographic rainfall.

Question 6.
What is ‘Rain shadow’ area?
Answer:
After raining heavily in windward side when the air reaches in the leeward side the amount of water vapour reduces. As the air descends, it gets heated and the capacity of holding water vapour increases. So the air becomes unsaturated and rainfall does not occur from such air in leeward side. Thus it is called Rain Shadow area or region.

Long Questions & Answers : (3 marks for each question)

Question 1.
Write about the origin of clouds.
Answer:
Water evaporating from seas, rivers and ponds on being heated up by sunlight is a source of water vapour in air. Transpiration from plants is another source. When air is laden with water vapour it becomes lighter and moves upward easily. Lower air pressure in higher altitude makes the moister laden air expand. The air also cools down in contact with the cooler air at higher altitude. Gradually the temperature of the moist air mass reaches its dew point and the air becomes saturated. When the saturated air cools down further, the water vapour in it condsnces to form small droplets of water. These water droplets settle around particles of dust, salt and other solid substances suspended in air and float in the air as cloud.

Question 2.
What is precipitation?
Answer:
Water droplets descending from the atmosphere to the surface of the air in the influence of gravitational pull is called precipitation. Clouds sailing in the sky are actually innumerable small droplets of water collected around dust particles. These clouds can be condensed further when they rise and come in contact with colder air. This is how the small droplets get together to form larger drops of water. These larger drops are too heavy to be held in suspension to the air. They respond to the attraction of gravity and are brought down as rain.

Question 3.
Write about cyclonic rainfall.
Answer:
If temperature increases in a small area, air over it warms up and rise. This leads to lowering of the local pressure and the formation of a centre of deep depression. The air surrounding this low pressure centreis cooler and exerts high pressure. Wind blows from the high pressure areas to the central low pressure at great speed, thereby generating a cyclonic storm. This is how a tropical cyclone forms. When the wind reaches the central low pressure cell, it gets warmer and a whirlwind starts moving upwards. This centripetal ascending air mass cools down and condenses causing torrential and thunderous rain. Rainfall thus caused by a cyclone is called Cyclonic Rainfall.

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 4 Pressure Belts and Winds offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 4 Question Answer – Pressure Belts and Winds

Textbook Page no. 36.

Question 1.
From which direction do Westerlies blow in the Southern hemisphere and what is the name given to such winds?
Answer:
At the time of blowing from southern Tropical High pressure belt to southern subpolar low pressure belt the Westerlies turns to the left according to Ferrell’s Law. Then it is known as North-West Westerlies.

Question 2.
Why are the Westerlies faster in the Southern hemisphere?
Answer:
The world masses are more than land masses in southern hemisphere and so the Westerlies blows faster here.

Question 3.
From which direction does the Polar wind blow in the Southern hemisphere according to the Ferrell’s Law and what is its called?
Answer:
In Southern hemisphere the wind blowing form south pole and turns to the left and it is known as south-east Polar wind.

Question 4.
why is Polar wind cold?
Answer:
Polar wind generates from extremely cold region. So which region the wind passes through the temperature decreases.

Textbook Page no. 37.

Question 1.
Which winds bring rain to China in Asia, Etheopia in Africa and Mexico in North America?
Answer:
For the influence of Westerlies.

Textbook Page no. 39.

Question 1.
which wind brings more rainfall to coastal areas?
Answer:
Sea wind brings more fainfall to coastal areas.

Question 2.
Which wind would help boats sail as they venture out into the sea or river at dawn?
Answer:
With the help of Landwind.

Question 3.
From which direction would the cool breeze come in a coast or a river bank in the evening?
Answer:
From the sea.

Textbook Page no. 40.

Question 1.
Why is there almost no rainfall from the winter Monsoon Wind?
Answer:
In winter dry cool wind blows from the land to sea. Thus rainfall does not occur.

Question 2.
Why is monson wind elassified as periodic wind?
Answer:
Monsoon wind blows in a certain season of the year, certain time of the day for the variation of the temperature. So it is called Perodic Wind.

Class 8 Geography Chapter 4 Question Answer West Bengal Board – Pressure Belts and Winds

Multiple Choice Questions & Answers : (1 mark for each question)

Question 1.
The region extends through 50 of latitude to the north and south of the equator is –
i) Equatorial region
ii) Polar region
iii) Tropical region
Answer:
i) Equatorial region.

Question 2.
The other name of equatorial region is-
i) Coriolis
ii) Doldrums
iii) Horse Latitudes
Answer:
ii) Doldrums

Question 3.
The region between 25° and 30° parallels of latitude in the Northern and Southern Hemisphere is called-
i) Subpolar region
ii) equatorial region
iii) Tropical calm zone
Answer:
iii) Tropical calm zone.

Question 4.
The temperature of two poles remains the ice point throughout the year-
i) over
ii) below
iii) within
Answer:
ii) below.

Question 5.
Two tropical region between 250 and 300 parallels of latitude is known as-
i) Horse Latitude
ii) Coriolis
iii) equatorial region
Answer:
i) Horse latitude.

Question 6.
The difference between the air pressure of two regions is responsible for-
i) changing the direction of wind
ii) changing the speed of the wind
iii) blowing wind
Answer:
iii) blowing wind

Question 7.
The scientist who first said about the deflective force is-
i) G. G. Coriolis
ii) M. Sen
iii) Willium Ferrell
Answer:
i) G. G. Coriollis.

Question 8.
Buys Ballot Law was introduced in-
i) 1855
ii) 1856
iii) 1850
iv) 1857
Answer:
iv) 1857

Question 9.
Dry cold polar winds blow from high pressure belt to low pressure belt
i) all through the year
ii) sometimes
iii) periodically
Answer:
i) all through the year.

Question 10.
Westerlies blow in the southern hemisphere than the northern-
i) faster
ii) slower
iii) equally
Answer:
i) faster.

Question 11.
Westerlies blowing with a violent howl along the 60 south parallel of latitude is-
i) Roaring Forties
ii) Furious Fifties
iii) Screaming Sixtics
Answer:
iii) Screaming Sixties.

Question 12.
In the Northern hemisphere Polar winds blow between 70° N and 80° N-
i) latitude
ii) longitude
iii) not any of them
Answer:
i) latitude

Question 13.
The apparent migration of the sun occurs within-
i) 22nd. March-21st. June
ii) 22 nd. Sep.-21st. July
iii) 22nd Dec.-21st.June
Answer:
iii) 22nd. Dec. 21st. June

Question 14.
In agriculture the coasts of the Mediterranean sea are-
i) under-developed
ii) well-developed
iii) medium
Answer:
ii) well developed.

Question 15.
The Tundra Region is completely covered in ice for-
i) 7-8 months
ii) 6-7 months
iii) 8-9 months
iv) 3-4 months
Answer:
iii) 8-9 months.

Question 16.
The temperate grass land that located in the central and eastern parts of the continents are called-
i) Havard grassland
ii) mangrove forests
iii) Central Asian Steppis
Answer:
iii) Central Asian steppis.

Question 17.
The winds that blow particular time in the year is called-
i) periodic wind
ii) Local wind
iii) Sea brecze
Answer:
i) periodic wind

Question 18.
The cold wind blows from sea to land is called-
i) land breeze
ii) sea breeze
iii) Trade wind
Answer:
ii) Sea breeze.

Question 19.
At night the wind that blows from land to sea is called-
i) Trade wind
ii) perodic wind
iii) land breeze
Answer:
iii) Land breeze.

Question 20.
The another name of mountain wind is-
i) Anabatic wind
ii) Katabatic wind
iii) land breeze
Answer:
ii) Katabatic wind

Question 21.
The another name of valley wind is-
i) Anabatic
ii) Katabatic
iii) Parmanent wind
Answer:
i) Anabatic

Question 22.
Wind blowing in different parts of the earth at different times in the year due to local factors are called-
i) Land breeze
ii) Permanent wind
iii) Local wind
Answer:
iii) Local wind.

Question 23.
Pompero blows over-
i) Libiya
ii) Pampas region
iii) Guinea coast
Answer:
ii) Pampas region.

Question 24.
Chinook blows over-
i) Pampas region
ii) Guinea coast
iii) the eastern slope of Rocky mountain
Answer:
iii) the eastern slope of Rocky mountain

Question 25.
Harmattan blows over-
i) Guinea Coast
ii) Pampas region
iii) the Rocky. mountain
Answer:
i) Guinea coast

Fill in the blanks : (1 mark for each question)

1. The ______ region extends through 5° of latitude to the north and south of the equator.
2. The ______ movement of air over the earth’s surface is called air current.
3. The horizontal movement of air parallel to the earth’s surface is called ____
4. The two polar regions have temperature below _____ almost all through the year.
5. The two Tropical region is known as _____.
6. The rotation of the earth results in a force that causês an frèe flowing and mobile objects on earth to change direction and deflect. This deflective force is known as ______.
7. The American meteorolist _____ first mention the similarities swinging of clock with the swinging of provalent wind.
8. First _____ mentioned the coriollis Force .
9. The Coriollis Foree is mentioned in _____.
10. Buys Ballot Law is named after _______.
11. _____ are the winds blowing from Northern and Southern Tropical high pressure belt to the Equatorial low pressure belt through out the year.
12. The equatorial region where the North East and South East Trade wind meet is called ______.
13. _____ blow between 35° and 60° north and south parallels of latitudes.
14. The winds blow along 40° south parallels of latitude to the east is called _____.
15. Westerlies blowing with a violent howle among the 60° south parallel of latitude is called ______.
16. Extremely fast westerlies along the 50° south parallel of latitude is called ______.
17. With the variation of the parallels of latitude the temperature of air ______.
18. As the Trade wind blow from the less warm tropics to the warmer equatorial region, they get progressively ______.
19. The livehood of the people of ______ is rather difficult.
20. In winter watermass remains ______ than landmass.
21. The coasts of the Mediterranean sea are well developped in terms of ______ and ______.
22. The influence of Polar wind is found in ______ region.
23. ______ winds in both hemisphere blow from freczing cold regions to comparatively less region.
24. The ______ Region is completely covered in ice and has a lengthy spanning through 8-9 months.
25. At night the wind blows from ______ to sea.
26. The durinal difference in temperature between opposite seasons leads to the formation of ______.
27. The another name of ‘mountain wind’ is ______.
28. The another name of ‘valley wind’ is ______.
29. When the air pressure suddenlly drops over a small area, pressure is generally ______ in the centre.
30. In a cyclone wind speed can shoot up to about ______ km per hour.
31. Tropical cyclones are ______.
32. When the prevalent condition is just opposite to the cyclone, it is called ______.
33. Sirocco is one type of ______.
34. The word ‘chinook’ means ______.
35. Boro blows through the coast of the ______.
36. Fohn is one type of ______.
37. ______ is characterized by the dry and dusty northeasterly trade wind.
38. Fohn is found in the ______.
39. After the name of G. G. Coriolis the deflective force is called ______.
Answer:
1. equatorial region
2. vertical
3. wind
4. freezing point
5. Horse Latitude
6. Coriolis Force
7. William Ferrell
8. G. G. Coriollis
9. 1835 A.D
10. Buys Ballot
11. Trade wind
12. Inter Tropical convergence zone
13. Westerlies
14. Westerlies
15. Screaming sixties
16. Furious Fifties
17. varies
18. warmer
19. Sahara desert
20. warmer
21. agriculture, communication
22. Tundra
23. Polar, cold
24. Tundra, winter
25. Land
26. Monsoon wind
27. Katabatic wind
28. Arabatic wind
29. lowest
30. 160
31. destructive
32. anticyclone
33. local wind
34. snow eater
35. Adriatic sea
36. local wind
37. Harmattan
38. northern slope of Alps
39. Coriolis Force.

State whether True or False : (1 mark for each question)

1. Land breeze blows from the land towards the water at night.
2. Periodic winds are winds that blow during a particular time in the year.
3. Anticyclones are generally formed in low latitudes.
4. ‘Mountain wind’ is called local wind.
a. The he wind of rocky mountain is example of local wind.
6. Trade winds blow between 25° and 30° north and south parllels of latitude.
7. Wind is named after the direction fron which it flows.
8. William Farrel was a British scientist.
9. The equatorial region has more water than landmass.
10. Westerlies blows from the east.
11. Two air masses of opposite nature meet at the Tropics.
12. The wet hot polar winds blow throughout the year from polar low pressure belts to sub polar belts.
13. Periodic winds are winds that blow during a particular time in the year.
14. Tropical cyclones are constructive.
15. The higher slopes in Kulu and Kangra valleys are more populated than the valley floors.
Answer:
1. true
2. true
3. false
4. false
5, true
6. false
7. true
8. false
9. true
10. false
11. true
12. false
13. true
14. fale
15. true

Match the column A with column B.

Column A	Column B
a) Land breeze	i) the air is super cool and heavy
b) Sea breeze and Land Breeze	ii) tropics and the poles
c) Inter Tropical Convergence Zone	iii) meet at the Tropics
d) Coriolis Force acts generally	iv) different parts of the earth’s surface
e) In polar regions	i) occur everyday
f) The air is denser in the	ii) picks up speed at dawn.
g) Two air masses of opposite nature	iii) on the naturally flowing winds
h). Ships come to a stndstill	iv) is cold
i) Atmosphere pressure varies over	i) in the Horse Latitude
j) Polar wind	ii) is known as Equatorial calm region

Answer:
a) Land breeze picks up speed at dawn.
b) Sea breeze and Land Breeze occur everyday.
c) Inter Tropical Convergence Zone is known as Equatorial calm region.
d) Coriolis Force acts generally on the naturally flowing winds.
e) In polar regions the air is super cool and heavy.
f) The air is denser in the tropics and the poles.
g) Two air masses of opposite nature meet at the Tropics.
h) Ships come to a stndstill in the Horse Latitude
i) Atmosphere pressure varies over different parts of the earth’s surface.
j) Polar wind is cold.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
What is wind?
Answer:
The horizontal movement of air parallel to the earth’s surface is called wind.

Question 2.
What is air current?
Answer:
The vertical movement of the air over the earth’s surface is called air current.

Question 3.
Which region is called Doldrums?
Answer:
Equatorial calm zones.

Question 4.
Which region is called Horse-latitude?
Answer:
Tropical regions (25°-35°N. and S) are known as Horse-latitude.

Question 5.
How does the coriolis Force acts?
Answer:
Coriolis Force acts as a right angle to the direction of flow of wind.

Question 6.
How is the wind named?
Answer:
Wind is named after the direction from which it blow.

Question 7.
When was Buys Ballot Law find out?
Answer:
Buys Ballot law was found out in 1857.

Question 8.
What is the speed of Trade wind in Northern Hemisphere?
Answer:
Trade winds travel 16 km per hour in Northern Hemisphere.

Question 9.
What is ITCZ?
Answer:
The North East and South East Trade winds meet in the Equatorial Region. This is the Inter Tropical Convergence Zone or the ITCZ.

Question 10.
What is the other name of ITCZ?
Answer:
The other name of ITCZ is Equatorial calm region.

Question 11.
What is Roaring Forties?
Answer:
Westerlies blowing with a howl aiong the 40° south parallel of latitudes.

Question 12.
What is Furious Fifties?
Answer:
Extremely fast Westerlies along the 500 south parallel to latitude.

Question 13.
What is Screming Sixties?
Answer:
Westerlies blowing with a violent how along the 600 south parallel of latitude.

Question 14.
What is the source of the temperature of air?
Answer:
The source of air temperature is Sun.

Question 15.
How is the livehood of the people of Sahara desart for the influence of Trade wind?
Answer:
The ivehood here is rather difficult.

Question 16.
How is the livehood of the people of Mediterranean coast for the influence of westerlies?
Answer:
Prosperous in scope of employment.

Question 17.
Which region experiences blizzards for Polar wind?
Answer:
Siberia in Russia somctimes experience blizzards in polar wind.

Question 18.
When do the Periodic Winds blow?
Answer:
Periodic winds blow during a particular time in the year.

Question 19.
Where is the effect of Sea Breeze found?
Answer:
The effect of Sea-Breeze is found till 150 km. inland the coast line.

Question 20.
When the influence of Land Breeze increases?
Answer:
The influence of Land Breeze increases at dwon.

Question 21.
Which wind is called the larger verson of Sea and Land Breeze.
Answer:
Monsoon wind is cousdeered the larger verson of sea and I and Breeze.

Question 22.
Name two valleys of Himachal Pradesh.
Answer:
The two valleys of Himachal Pradesh are Kulu and Kangra.

Question 23.
Where is Chinook found?
Answer:
Chinook is found in Rocky mountain region of North America.

Question 24.
What does the term ‘Chinook’ mean?
Answer:
The term ‘Chinook’ means ‘Snow eater’.

Question 25.
What is the nature of Chinook?
Answer:
Chinook is dry and hot.

Question 26.
Where are the Cattles reared for the influence of Chinook?
Answer:
For the influence of Chinook the cattles are reared in Prairies.

Question 27.
Where is Fohn found?
Answer:
Fohn is found in Alps mountain region.

Question 28.
What is the nature of Fohn?
Answer:
Fahn is dry and warm.

Question 29 .
What happens due to the influence of Fahn?
Answer:
Due to the influence of Fahn the temperature rises.

Question 30.
How is Harmattan?
Answer:
Harmattan is dry and cold.

Question 31.
Where is Harmattan found?
Answer:
Harmattan blows over the Guinea coast from the eastern part of North West Anerica.

Question 32.
What is the Doctor wind?
Answer:
Harmattan is called the Doctor wind.

Question 33.
Why is Harmattan called the ‘Doctor’?
Answer:
It is because the wind provides relief from the warm moist and sultry wtither in the Tropical region.

Question 34.
How is Bora?
Answer:
Bora is dry and cold.

Question 35.
Where is Bora found?
Answer:
Bora blows through the coast of the Adriatic sea after descending along the southern slope of Alps.

Question 36.
What happens due to the influence of Bora.?
Answer:
This excessive cold wind disrupts normal life is southern Europe along the coast of the Adriatic sea.

Question 37.
What is Pompero?
Answer: Pampero is one of a local winds.

Question 38.
Where is Pampero found?
Answer:
Pampero originates in the Southern parts of South America and blows over Pampas region.

Question 39.
How does Pampero effect on human life?
Answer:
For the influence of Pampero the life of the people becomes comfortable.

Question 40.
Where is Sirocco found?
Answer:
Sirocco is originated in Libyan desert of Africa and blows over Southern Europe.

Question 41.
What type of wind is Sirocco?
Answer:
Sirocco is dry, warm and dusty.

Question 42.
How is the coast of Africa influenced by Sirocco?
Answer:
For the influence of Sirocco the northern coast of Africa is dried up and covered with dust.

Question 43.
Give examples of local wind blowing in India.
Answer:
Loo and Andhi.

Question 44.
What is the speed of Trade Wind in southern hemisphere?
Answer:
The speed of Trade Wind in southern hemisphere is 22-30 km. per hour.Short

Short Questions & Answers : (2 marks for each question)

Question 1.
What is coriolis Force?
Answer:
The rotation of the earth results in a force that causes all free flowing and mobile objects on earth to change direction and deflect. This is called Coriolis Force.

Question 2.
What is Buys Ballot’s Law?
Answer:
When one faces the wind in the Northern Hemisphere pressure is more towards the right and lower on left. Just opposite condition is seen in the Southern Hemisphere.

Question 3.
Which wind is called winter Monsoon wind?
Answer:
In winter cold, dry, wind blows from landmass towards the ocean. This is called Winter Monsoon Wind.

Question 4.
Which is called Summer Monsoon Wind?
Answer:
In summer moisture laden wind blows from ocean towards the land. That is called Summer Monsoon Wind.

Question 5.
What is Anabatic Wind?
Answer:
Sometimes the air over the valley does not heat up as much as that over the slopes flanking the valleys during day time. Therefore, the air pressure is comparatively highrer whereas the temperature is lower in the valley.nAir from the valley rises along the slopes. This is known as Anabatic Wind.

Question 6.
What is Catabatic Wind?
Answer:
At night the slopesradiate heat faster as the air over the mountain slopes cools down and high pressure prevails here. This heavy air from the high pressure descends and settles down in the valley. This is known as Catabatic Wind.

Question 7.
What is meant by periodic Wind?
Answer:
There are some winds that blow during a particular time in the year or a particular time of the day. These winds do not blow throughout the year like the planetary winds. These are called periodic winds.

Question 8.
What is Doldrums?
Answer:
In equatorial region upward air current is observed. There is no horizontal movement of air. This leads to the prevalence of calm conditions. So this is the zone of equatorial calm. This region is called ‘Doldrums’ which mean calm.

Question 9.
What is Sub-tropical regions?
Answer:
The region between 25° and 30° parallels of latitude in the Northern and Southern Hemispheres are respectively called the Northern sub-tropical and Southern sub-tropical regions.

Question 10.
Mention three segments of Inter Tropical Convergence Zone.
Answer:
The segment extending through the indian Ocean and the Pacific Ocean is the largest one. The second segment is found to the west of Africa in the Atlantic Ocean. The third segment is also on the pacific Ocean to the west of South America.

Question 11.
How trade winds get such name?
Answer:
Ancient commercial vessels used these winds in their sails to carry the cargo along certain marine routes. These winds them in trading. So these winds got their name as trade wind.

Question 12.
Mention the features of Sea breeze and Land breeze?
Answer:

1. Sea breeze and Land breeze occur everyday.
2. These winds blow at a regular interval each day.
3. Generally the effect of these winds are found till 150 Km. inland from the coastline.

Question 13.
How cyclone is formed?
Answer:
When air pressure suddenly drops over a small area, pressure is generally lowest at the centre. Then wind blows at high speed towards the central low pressure zone from higher pressure. this is called cyclone.

Long Questions & Answers : (3 marks for each question)

Question 1.
Why are the pressure belts formed?
Answer:
The hot and wet air of equatorial region rises up. The temperature reduces as the air rises up. On cooling the weight and density increases. The cool and heavy air sinks in the Northern and Southern Tropical region. Cool and dry air from polar region also sinks dwon in these two Tropical regions. Two air masses of defferent characters meet at the Tropic and the mass and density of air increase.

Question 2.
What is Horse Latitude?
Answer:
In sixteenth century ship from West Indies and Europe used to come stand still in Northern and Southern Tropical region because there was no air in their soil. The vessels carrying horses used to take much time to reach the West Indies and America. To avoid the crises of food and water the crews sacrificed some of the horses by throwing them into the Atlantic Ocean for reducing the weight of the ship. Therefore the Tropical regions are called the Horse latitudes.

Question 3.
What is Cyclone and Anti cyclone?
Answer:
When air pressure suddenly drops over a small area a low pressure creates at center and a high pressure creates at the surrounding zoncs. In the situation air blows from high pressure area to low pressure area. This is called cyclone.

When temperature of an area drops suddenly the air pressure increases. Then high pressure creates at the centre and a high pressure creates at the surrounding zones. In this situation air blows from centre to outwards. As the condition is just opposite of that of cyclone. So it is called the Anti cyclone.

Question 4.
Describe Ferrell’s Law.
Answer:
One type of force acts on any free flowing object on the earth for the revolution of earth. This deflects the direction of the moving objects. At the time of flowing from high pressure zone to low pressure zone the wind deflects towards right in the Northern hemisphere and to the left in Southern hemisphere for this reason. This is known as Ferrell’s Law.

Question 5.
What is Summer Monsoon wind and Winter monsoon wind?
Answer:
Monsoon winds blows through the Indian peninsula. In summer when the land get heated quickly by the sunrays the low pressure belt creates. But the water of Indian ocean remains cooler then and high pressure creates over there. Thus the moisture laten winds blows from ocean to land mass in :ummer which is called Summer Monsoon Wind.

In winter the landmass cools rcadily by radiating the sun heat and create high pressure belt over there. The water of Indian ocoan remains cooler, hotter then and low pressure belt creates there. Therfore, dry cool air tlows from land to sea in winter which is called winter monsoon wind.

Question 6.
What is permanent winds? Classify permanent winds. The winds that blow horizo”tally through out the year in the same direction at uniform speed are calied permanent winds.
Answer:
There are three types of permanent winds Trade wind, westerlies, Polar wints. Trade wind : The winds that blow from Northern and Southern Tropical high pressure belts to equatorial low pressere belt regularly, throughout the year are called Trade wind.
Westerlies : The winds that blow from Northern and Southern Tropikeal High pressure belt to Northern and Southern subpolar belts are called Westerlies. Polar winds The hot and dry winds blow from polar high pressure belt to subpolar low pressure belt in both hemisphere are called Polar wind.

Question 7.
What is Periodic winds? Compare Sea Brecze and Land Breeze.
Answer:
The winds that blow in a particular time in the year or a particuler time of a day are called Periodic winds.
Sea Breeze : The cool breeze that blows from sea to land in the afternoon or evening is called Sea Breeze. The difference between the air pressure of land and sea is responsible for the wind blowing.
Land Breeze : The land gets heated quickly and becomes cool by raducting the heat than the water mass. At night when the land entirely cools down the water still retain some heat and is warmer. A low pressure belt creates on the water and wind blows from land to sea at night which is called Land Breeze.

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 3 Rocks offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 3 Question Answer – Rocks

Textbook Page no. 23.

Question 1.
Why are crystals not formed in sedimentery rocks?
Answer:
The hardness of the sedimentery rock is less than igneous rock. Therefore, sedimentery rocks do not have crystalline structure.

Question 2.
Why are fossils not found in igneous rocks?
Answer:
Due to excessive pressure and heat the inagma from earth’s interior comes out as lava and solidifies either on the earth’s surface or in the earth chamber to form igneous rock. So the fossil is not found.

Question 3.
From which type of rock is extraction of minerals convenient and why?
Answer:
In sedimentary rock mining is easy. Near about 7-10 crore years ago many organisms got burried under the layer of the sedimentary rocks. For the excessive pressure of upper layer and heat of the earth chamber the remaining parts of the body changes into the solution of hydrogen and carbon and different types of minerals are formed. So only the porous layer of sedimentery rock is called the store house of the minerals.

Textbook Page no. 26.

Question 1.
Which rocks are laid between and near a pair of railway tracks? Why are these rocks found here?
Answer:
In between railway track generally granite is found. It is because granite is very much resistant to erosion.

Question 2.
why does a piece of granite glitter?
Answer:
Glittering substance like mica is present in granite. This is because granite glitters.

Question 3.
Which rock is used to make a pencil lead?
Answer:
The lead of the pencil is made up of graphite, a metamorphic rock.

Question 4.
I am glittery, black or white. I am soft and malleable. I am a main constituent mineral of Granite. Can you say who I am?
Answer:
Quartz.

Identify me Page no. 27.

Question 1.
I have a smooth and attractive appearance. I am used in making floors. I have been used in constructing famous archetectural landmarks including the Victoria Memorial.
Answer:
Marble.

Question 2.
I am a very hard, fine grained grey black rock. I am commonly used in constructing roads. Water can easily pass through me.
Answer:
Gneiss.

Match the following :
Answer:

1. Limestone	Stalactite.
2. Sandstone	Sedimentary Rock.
3. Granite	Rounded dand form.
4. Great pressure	A cause of metamorphosis of rock.
5. Basalt	Flat topped landform.
6. Marble	Metamorphic rock.
7. Potassium	Plagioclase Feldsper.
8. Calcium Sulphate	Gypsum.

Class 8 Geography Chapter 3 Question Answer West Bengal Board – Rocks

Multiple Choice Questions& Answers : (1 mark for each question)

Question 1.
The characteristics of landform formed by Granite-
i) cavesquare
ii) flatsquare
iii) roundsquare
iv) steep slope
Answer:
iii) round.

Question 2.
The characteristics of landform formed by basalt-
i) cavesquare
ii) flatsquare
iii) roundsquare
iv) steep slope
Answer:
ii) flat.

Question 3.
The characteristics of landform formed by limestone-
i) cavesquare
ii) flatsquare
iii) roundsquare
iv) steep slope
Answer:
i) cave.

Question 4.
The characteristics of landform formed by sandstone-
i) cavesquare
ii) flatsquare
iii) roundsquare
iv) steep slope
Answer:
iv) steep slope

Question 5.
Slate is used in making-
i) cementsquare
ii) blackboardsquare
iii) iron industrysquare
iv) roads
Answer:
ii) blackboarc

Question 6.
Peat coal can be metamorphosed to graphite due to-
i) great pressuresquare
ii) chemical reactionsquare
iii) great heatsquare
iv) none of these
Answer:
iii) great heat

Question 7.
Amphibolite is the metamorphosed form of-
i) granitesquare
ii) sandstonesquare
iii) peat coalsquare
iv) mud stone
Answer:
i) granite

Question 8.
Victoria Memorial is made of-
i) granitesquare
ii) basattsquare
iii) mudstonesquare
iv) marble
Answer:
iv) marble

Question 9.
Fossils are found only in-
i) igneous rocks
ii) metamorphic rocks
iii) sedimentary rocks
Answer:
iii) sedimentary rocks

Question 10.
Sorrect metamorphosed form is-
i) graniterightarrow marble
ii) limestonerightarrow graphite
iii) sandstonerightarrow amphibolitesquare,
iv) basaltrightarrow amphibolite
Answer:
iv) basaltrightarrow amphibolite

Correct the wrong : (1 mark for each question)

Question 1.
The extrusive igneous rocks are generally fine grained because lavas after coming over the surface are slowly cooled and solidify.
Answer:
The extrusive igneous rocks are generally fine grained because lavas after coming over the surface are quickly cooled and solidify.

Question 2.
The amount of basic oxide in peridotite rock as 55%-45%.
Answer:
The amount of basic oxide in peridotite rock is more than 55%.

Question 3.
Andresite is one type of intrusive igneous rock.
Answer:
Andresite is one type of extrusive igneous rock.

Question 4.
Land forms developed on the regions of granite rock are mainly of round shaped.
Answer:
Land forms developed on the regions of granite rock are mainly of flat shaped.

Question 5.
The granite is composed of otvin and pyroxene.
Answer:
The granite is composed of mica and hornblends.

Question 6.
Igneous rocks are the store house of coal, petroleum and natural gas.
Answer:
Sedimentary rocks are the store house of coal petroleun and natural gas.

Question 7.
High permeability increases the water retaining capacity.
Answer:
High permeability reduces the water retaining capacity.

Question 8.
Fossil is found in metamorphic rocks.
Answer:
Fossil is found in sedimentary rocks.

Question 9.
Chemically formed sedimentary rock is conglomerate.
Answer:
Mechanically formed sedimentary rock is conglomerate.

Question 10.
Limestone is resistant to erosion and less permeable.
Answer:
Limestone is not resistant to erosion and highly permeable.

Question 11.
Bright crystalline structure is found in sedimentary rocks.
Answer:
Bright crystalline structure is found in igneous rocks.

Question 12.
Gneiss is harder than granite.
Answer:
Gneiss is less harder than granite.

Question 13.
The region predominated by limestone is suitable for constructing high rise building, roads etc.
Answer:
The region predominated by granite is suitable for constructing highrise building, roads etc.

Question 14.
Quartz is used for making glass.
Answer:
Quartz is used for cutting glass.

Question 15.
Mica is good conductor of heat and electricity.
Answer:
Mica is poor conductor of heat and electricity.

Question 16.
In Mah’s scale the value of harlness of diamond is 8.
Answer:
In Mah’s scale the value of hardness of diamond is 10.

Question 17.
The main element of plagioclase feldsper is Potassium.
Answer:
The main element of plagioclase feldspar is Sodium.

Question 18.
The main occupation of Chotanagpur plateau region is agriculture.
Answer:
The main occupation of Chotanagpur plateau region is mining and mine-based industry.

Question 19.
The soil derrived from basalt rock is infertile.
Answer:
The soil derrived from basalt rock is suitable for wheat and cotton.

Question 20.
The grains of sandy soil is smaller.
Answer:
The grains of sandy soil is bigger.

Question 21.
Sandy soil is found in North Indian plain.
Answer:
Alluvial soil is found in North Indian plain.

Question 22.
The fertility of clayey soil is more.
Answer:
The fertility of clayey soil is medium.

State whether True or False : (1 mark for each question)

1. In Mah’s scale the mineral with value of hardness 7 is Quartz.
2. Limestone disolves in water:
3. Sandstone is used in architectural works.
4. The colour of shale may be yellow, red, orange, pink etc.
5. Rocks can be metamorphosed in different ways.
6. When sedimentary rock metamorphosed it becomes brittle.
7. Marble is the metamorphosed form of limestone.
a. It is easy to mine from marble.
9. The metamorphosed form of sandstone is Qurartzite.
10. No landform is found in the limestone dominated region.
11. Feldspar is as smooth as slate.
12. Mica is used for making glass.
13. Regolith is the main composition of soil formation.
14. The soil made up of basalt is white.
15. The alluvial soil is the most suitable for agriculture.
Answer:
1 true
2. false
3. true
4. false
5. true
6. false
7. true
8. false
9. true
10. false
11. true
12. false
13. true
14 false
15. true

Fill in the blanks : (1 mark for each question)

1. __________ is a clastic rock.
2. Crystal may be __________ or hexagonal in shape.
3. Cometite is a _______ rock.
4. The diameter of the particle of gabbro is _________ mm.
5. The continental plate is made up of _________.
6. The chief constituent minerals of Basalt is _________.
7. __________ are found is sedimentery rock.
8. High _________ reduces the water retaining capacity of rocks.
9. ________ is the sedimentery rock of silicate.
10. The golden fort of Joysalmeer is made up of ___________.
11. Graphite is the _________ form of peat coal.
12. The example of a rock with fine grains is ___________.
13. Sedimentery rocks become less ________ when metamorphosed.
14. Marble readily melts in _________
15. ___________ is not as hard as ganite.
16. Sometimes lime formation may rise from the cave floors which is called ________.
17. For the construction high rise buildings and road the region with __________ is suitable.
18. Diamond is metamorphosed torm of __________.
19. Most of the rock forming minerals is made up of ________ eliment.
20. Mica may be of the white ____________.
21. Mica is _________ of heat and electricity.
22. ____________ is a hydrated crystal of Calcium Sulphate.
23. The influence of __________ is verv much evident in nature.
24. The soil predominated by Zypsum is soft and ___________ in colour.
25. The main occupation in Chotanagpur plateau region is mining and __________.
26. Characteristic features of a soil usually depend on the ____________ of the layer of rock underneath.
27. Soil derived from Basalt is suitable for growing ___________.
28. The soil derived from _________ is found in Chotanagpur plateat.
29. Grains of minerals are very _________.
Answer:
1. conglomerate
2. cubic
3. ultra basic rock
4. 3, 5. granite
6. Pyroxene
7. layers
8. permeability
9. flint
10. sandstone
11. metamorphose
12. mudstone
13. brittle
14. acid
15. granite
16. stalagmites
17, granite rock
18. carbon
19.8,20. muscovite
21. poor conductor
22. zypsum
23. mineral
24. light yellow
25. mining based industry
26. nature
27. wheat and cotton
28. granite
29. fine.

Match the column A with column B.

Column A	Column B
a) In igneous rocks	i) crosion resistant rock
b) Sedimentery rocks	ii) porous sedimentary rocks
c) Basalt is highly	iii) mainly from basalt
d) Sand remains loose and light	iv) crystalline structure is found
e) Shale is widely used	i) heat and electricity
f) Petrolium is available only in the	ii) are highly permeable
g) Constracting dams in a limestone	iii) of calcium sulphate
h) Black soil is made	iv) when it is dry
i) Gypsum is a hydrated crystal	i) terrain is not the right thing to do
j) Mics is a poor conductor of	ii) in making roof-tiles of buildings

Answer:
a) In igneous rocks crystalline structure is found.
b) Sedimentery rocks are highly permeable.
c) Basalt is highly erosion resistant rock.
d) Sand remains loose and light when it is dry.
e) Shale is widely used in making roof-tiles of buildings.
f) Petrolium is available only in the porous sedimentary rocks.
g) Constracting dams in a limestone terrain is not the right thing to do.
h) Black soil is made mainly from basalt.
i) Gypsum is a hydrated crystal of calcium sulphate.
j) Mics is a poor conductor of heat and electricity.

Very Short Questions& Answers : (1 mark for each question)

Question 1.
How can be igneous rock divided according to origin?
Answer:
According to origin igneous rock is of two types.

Question 2.
Name an extrusive igneous rock.
Answer:
Basalt.

Question 3.
Name a hypabyssal igneous rock.
Answer:
Dolorite

Question 4.
At what percent Silica is present in acidic rock?
Answer:
More than 60%.

Question 5.
What is the diameter of the particle of extrusive rock?
Answer:
‘ess than 1 mm.

Question 6.
At what amount basic oxide is present in acidic rock?
Answer:
More than 55%

Question 7.
How are the lasdforms developed with granite rock?
Answer:
Round shaped.

Question 8.
How are the land forms developed with basalt rock?
Answer:
Flat shaped.

Question 9.
What is the diameter of the particle of hypabyssal rocks.
Answer:
More than 3 mm.

Question 10.
Which rocks have high permeability?
Answer:
Sandstone.

Question 11.
In which rock layer mineral oil and natural gas are found?
Answer:
Only in porous sedimentary rock.

Question 12.
Name a sedimentary rock iron stone typed.
Answer:
Haematite.

Question 13.
What is rock?
Answer:
Rocks are homogenous or heterogenous aggregates of one or more minerals.

Question 14.
What minerals the granite rock is composed with?
Answer:
Granite rock is composed with quartz, feldsper. mica and hornblends.

Question 15.
What minerals the limestone is composed with?
Answer:
Limestone is composed with calcite.

Question 16.
What is petrology?
Answer:
The special branch of science which deals with the rocks and their characteristics is known as petrology.

Question 17.
What is mineralogy?
Answer:
The branch of science which deals with minerals is called mineralogy.

Question 18.
What is the other name of igneous rocks?
Answer:
The other name of igneous rock is primary rocks.

Question 19.
Why is the grains of extrusive igneous rock are generally fine?
Answer:
The grains of extrusive igneous rock are generally fine because lavas after coming over the surface are quickly cooled and solidified.

Question 20.
What are the different types of intrusive igneous rocks.
Answer:
The different types of intrusive igneous rocks are hypabyssal and plutonic.

Question 21.
What type of rock is dolerite?
Answer:
Dolerite is one type of hypabyssal igneous rock.

Question 22.
How are crystals formed in igneous rocks?
Answer:
Crystals are formed as the atoms of the mineral water which remain in like veins after cooling of the rock.

Question 23.
Name some crystals.
Answer:
Some crystals are quartz. topaz, calcite. diamond.

Question 24.
What is the shape of the crystal?
Answer:
Crystals are either crystal or hexagonal in shape.

Question 25.
Give an example of intermediate rock? What amount of basic acid is present in it.
Answer:
An example of intermediate rock is andesite in whiç basic oxide is 45-35%.

Question 26.
At what amount of Silica is present in peridotite rock?
Answer:
More than 45% of silica is present in peridotite.

Question 27.
What type of rock is kimberlite.
Answer:
Kimberlite is ultra basic rocks.

Question 28.
What is the diameter of Granite rock?
Answer:
The diameter of granite rock is more than 3 mm.

Question 29.
What are the rock forming minerals of basalt?
Answer:
The chief constituent minerals of basalt are feldspar, olivin and pyroxene.

Question 30.
What is the diameter of the particle of Micro-diorite?
Answer:
The diameter of the particle of micro-diorite is 1-3 mm.

Question 31.
What is permeability?
Answer:
Permeability means penetration of liquid and gaseous substances through the rock.

Question 32.
What is porosity?
Answer:
Porosity means the ratio between the voids and total volume of a given rock mas.

Question 33.
Give an example of pyroelastic rock.
Answer:
An example of pyroelastic rock is tuff.

Question 34.
Name a chemically formed sedimentary rock.
Answer:
A chemically formed sedimentery rock is Gypsum.

Question 35.
What is diatom?
Answer:
Diatom is organically formed sedimentary rock.

Question 36.
Name a calcareous sedimentery rock.
Answer:
Limestone.

Question 37.
What is the scientific name of limestone?
Answer:
Calcium Carbonate.

Question 38.
How is limestone used?
Answer:
Limestone is used as a raw material in making cement and in iron and steel industry.

Question 39.
With which stone the Khajuraho temple is made?
Answer:
The Khajuraho temple is made up of sandstone.

Question 40.
Which rock is used to make roof tiles?
Answer:
Slate is used to make roof tiles.

Question 41.
How is slate formed ‘slab?
Answer:
Under tremendous pressure slab metamorphoses to form slate.

Question 42.
What is phyllite?
Answer:
Phyllite is one type of slate.

Question 43.
Into which peat coal is transformed?
Answer:
Peat coal is transformed into Graphite.

Question 44.
Which rock is used for making black board.
Answer:
Slate is used for making black board.

Question 45.
Which rock is used for the construction of road?
Answer:
Metamorphic rock, Granite is used for the construction of road.

Question 46.
Name an acidic rock.
Answer:
An acidic rock is Basalt.

Question 47.
Is the Decan plateau is the part of Decan trap?
Answer:
The dalite like land from with flat top at Panchagani Mahabaleshwar region is the part of Decan trap of Decan plateau.

Question 48.
What is Stalactites and Stalagmites?
Answer:
Stalactites and Stalagmites are limestone cave.

Question 49.
Where is granite rock found?
Answer:
Granite rock is found in entire Chotanagpur region including Ranchi.

Question 50.
Why is constructing dams and reservoirs in a limestone terrain is not the right thing to do?
Answer:
It is because rivers or rain water can crode limestone by solution. So the dam may easily crack.

Question 51.
In which region multistoried buildings and excessive length of road are not advisable?
Answer:
Multistoried buildings and excessive length of road are not advisable in limestone terrains.

Question 52.
What is the colour of ortho claye?
Answer:
Pink.

Question 53.
Name the rock forming minerals.
Answer:
Silicon, Oxygen.

Question 54.
Which mineral is used for making ornaments and cutting glass and stone?
Answer:
Quartz.

Question 55.
What is the main element of Plagioclase feldspar?
Answer:
The main element of plagioclase feldsper is Sodium.

Question 56.
What is the element of orthoclase?
Answer:
The main element of orthoclase is Potassium.

Question 57.
What is the use of feldspar?
Answer:
Feldspar is used in glass and ceramic industry.

Question 58.
Name a soft mineral.
Answer:
Zypsum.

Question 59.
What is Malı’s scale?
Answer:
Mah’s scale of hardness measures the hardness of minerals.

Question 60.
What is the hardness of corundum measured in Mah’s scale?
Answer:
The hardness of Corundum in Mah’s scale is 9.

Question 61.
How is the soil in the region with Gypsum?
Answer:
The soil is soft light yellowish in the region with Gypsum.

Question 62.
Name a soil with excessive mineral.
Answer:
Laterite soil and red soil.

Question 63.
Why is the soil, made up of granite, red?
Answer:
This is because the oxide of iron present in this soil at high amount.

Question 64.
What type of soil found in the desertic area of Rajasthan?
Answer:
Sandy soil.

Question 65.
Where is Mangrove forest found?
Answer:
Mangrove forest is found at the sea coast with saline soil.

Short Questions & Answers : (2 marks for each question)

Question 1.
Mention one difference of homogeneus and heterogeneus mixture.
Answer:
In homogeneus mixture all elements remain in equal ratio everywhere but in heterogeneus mixture all the elements lie in equal ratio in different places.

Question 2.
What is fossil? In which rock fossil is found?
Answer:
Marine plants and animals sometimes come within the beds of the sediments during compaction of layers to form sedimentery rock. Later dead remains of the organism leave their imprint into the layers of sediment after being solidified. This is called fossils.

Question 3.
What is rock cycle?
Answer:
In nature the formation of rocks and transformation of rocks have occured in cycling way in a specific method. The complete cyclic process of formation of rocks and their changes frum one type to the other is called the rock cycle.

Question 4.
What is regolith?
Answer:
Natural agents like river wind, rainfall, sea-waves, glacier etc. degrade rocks and minerals over a long time to form loose deleres of rock. This delere’s then interacts naturally with water air and organic matter to form soil. This delere’s of degraded rocks is called regolith.

why the Chotanagur Plateau is called ‘the store house of minerals’.
Answer:
Chotanagpur Plateau in India is rich in minerals like iron, copper, bauxite, manganese, dolomite etc. So it is called the storehouse of minerals’.

Question 6.
What is limestone?
Answer:
Limestone is a calcareous sedimentary rock. It is not generally soluble in water. But it gets readily dissolved in rainwater or acid solutions when it is transformed to calcium bicarbonate. Limestone may be white, grey, green or blackish in colour.

Question 7.
What is sandstone?
Answer:
Sandstone is a sedimentary rock rich in sand. It is resistant to erosion in spite of being highly porous and permeable. Architects use it in making epitaphs and monuments. It is yellow, orange, red, pink, white or grey in colour.

Question 8.
What is Marble?
Answer:
Marble is the metamorphosed form of lime stone. It is smoothy, glittery and attractive. It is available in a wide variety of colours including white, green, grey, yellow and blue. It is extensively used by architects.

Question 9.
What is slate?
Answer:
It is the metamorphosed form of mudstone or shale. It is smooth and biuish grey to black in colour. It is arranged into thin layers and can be easily broken. They are used in making oof tiles and blackboards and can be used as a surface for writing.

Question 10.
What is gneiss?
Answer:
This is a hard and resistant rock. The minerals in it are often arranged in bands. So this is called a banded rock. Extarcting a certain mineral from it is thus convenient. This rock is widely used to make roads and in other constructions.

Question 11.
What is quarz?
Answer:
Quartz is very hard, often whitish and hexagonal crystals. It is the main constituent of granite and Basalt. These rocks are very resistant to erosion due to the presence of quartz in them. It is used as stone cutter, glass cutter and in ornaments.

Question 12.
What is mica?
Answer:
Mica is lustrous, smooth, flaky and brittle in nature. It may be of the 1 , hite Muscovite or black Biotite varieties. Its presence gives granite its luster. Mica is a conductor of heat and electricity. It is used in preparing electrical goods.

Question 13.
What is shale?
Answer:
It is a sedimentary rock rich in clay. It is blackish grey in colour. Thin layers are seen in it. It is soft snd brittle rock. This rock is widely used in making roof-tiles of buildings.

Long Questions & Answers : (3 marks for each question)

Question 1.
Write a short note on Igneous Rock.
Answer:
It is also known as Primary rocks as these were the first rocks to originate on earth. This is also called primary rock. According to origin igneous rock is of two types Intrusive and Extrusive igneous rocks. Extrusive igneous rocks are generally fine grained besause lava after coming over the surfsce, is quickly cooled and solidified e.g-basalt, obsedian. When the rising magma foes not reach the earth’s surface, butis cooled and solidified below the surface of the earth, it is called intrusive igneous rock e.g-granite, dolerite.

Question 2.
Write a short note on sedimentary rock.
Answer:
Sediments and debris derived from the source through erosion snd transportation by natural agents of erosion like river, glacier, wind, sea waves are deposited under the water. Thus this types of rocks are called sedimentary rocks. Chalk, sandstone, mudstone are the example of sedimentary rocks. Layer and mud cracks are found in this rocks. Fossils are found in this rocks. These rocks are porous and also fragile. This type of rocks are highly permeable. Different sedimentary rocks have different degree of erosion resistant capacity. Sedimentary rock is the store house of coal, petroleum and natural gas. On the basis of composition sedimentary rocks are classifed into three groups i) mechanically formed sedimentary rocks, ii) Chemically formed sedimentary rocks, iii) Organically formed sedimentary rocks. Sedimentary are also classified according to the origin. Those are : i) Clastic rocks. ii) Non-clastic rocks.

Question 3.
Write a short note on metamorphic rock.
Answer:
Metamorphic rocks are formed by changing the physical and chemical characters of igneous and sedimentary rocks due to influence of great heat and pressure.
Metamorphic rocks may be crystalline. When an igneous change into metamorphic rocks, it is smoother, more lustrous and more crystalline. When a sedimentary rocks changes into metamorphic rocks it becomes less brittle. Besides, great heat and pressure erase out the fossils in a sedimentary rocks during metamorphism. Marble, slate are common metamorphic rocks.

Question 4.
What is rock cycle? Explain.
Answer:
The magma of asthenosphere comes out on the earth surface after eruption and flows of lava. Then cools to form igneous rock, or cools and solidify in the earth chamber to form igneous rocks. In due course of time the igneous rocks get eroded and accumulate under the sea, lake, ocean. After a long period of time this sediment changes this sedimentary rocks then this igneous rocks or sedimentary rocks change into metamorphic rock due to great heat, pressure or chemical reaction. Later for tiectonic movement the rocks may be brough back to interior of this earth where they melt and recycle as magma. Origin of rocks andtheir transformations and metamorphosis goes on in a cycle. The complete recycle process of formation of rocks and there change from one type to other is called the rock cycle.

Question 5.
What is the influence of mineral in soil?
Answer:
The influence of mineráls in nature is very distinct. The surface of the soil rich in iron and bauxite is very hard and red in colour. On the other hand soil, rich in Zypsum is soft and yellow in colour. Soil, rich in soft calcite, is erosion-prone. The places, where the mineral oil is found, are made up of porous, permiable sedimentary rocks. The soil with exclusive miniral is not fit for agriculture.

Question 6.
Write about formation of soil from rocks.
Answer:
For the action of different natural agents like river, wind, rainfall, ocean current, glacier current, the rock forming minerals are eroded and exist as the rock particle which mixes with water, air and different organic matter later and forms soil. The soil made up of basalt rock is black and is found in the Decan plateau region of India. The sandy soil is form in this that region with sandstone.

The colour of the soil is light, yellowish to grayish brown. The soil is not fit for agriculture. Sandy oil is found in the desertic region Rajasthan. In alluvial soil grains of the minerals are very fine. This type of soil is very fit for agriculture. The soil of North Indian plain is some in nature. The soil which is enrich with iron and Aluminium oxide excessively is called Laterite soil. This type of soil is not fertile. Laterite soil is found in Chota Nagpur and Meghalaya plateaus. Saline soil is found at the sea coast. Mangrove vegetation grows in this soil. This soil is found in the Sundarban region of West Bengal.

Question 7.
What is Karst Topography?
Answer:
There are natural caves in Cherrapunji-Mawsynram. Narrow, pointed, rocky structures hang from the seiling in these caves. These are limestone caves. The lime formations hanging from the roof are called Stalactites. Sometimes similar lime formations may rise from the cave floors. They are called Stalagmites. Rising Stalagmites and drooping Stalactites may join to form limestone pillars. This typical assemblage of landform is called Krast Topography.

Question 8.
Write three characteristics of igneous rocks.
Answer:
Three characteristics of igneous rocks-
i. Joints and cracks are very common in these rocks, so these are highly permeable.
ii. Crystaline structure is found.
iii. The Colour of these rocks vary from light to dark.

Question 9.
Write three characteristics of sedimentary rocks.
Answer:
Three characteristics of sedimentary rocks-
i. Layers and mudcracks are found in this type of rocks.
ii. Different sedimentary rocks have different capacity to resist c.osion.
iii. Reserves of coal, petroleum and natural gas are found within these rocks.

Question 10.
Write three characteristics of metamorphic rocks.
Answer:
Three characteristics of metamorphic rocks-
i. Metamorphism usually hardens igneous and sedimentary rocks.
ii. Igneous rocks get smoother, morelustrous and more crystalline with metamorplifsm.
iii. Sedimentary rocks become less brittle when metamorphosed.

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 2 Unstable Earth offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 2 Question Answer – Unstable Earth

Multiple Choice Questions & Answers : (1 mark for each question)

Question 1.
J. T. Wilson introduced the word ‘Plate’ in-
i) 1965
ii) 1906
iii) 1970
iv) 1955
Answer:
i) 1965

Question 2.
Machenziae and Parker gave information on plate movement in-
i) 1967
ii) 1990
iii) 1965
iv) 1960
Answer:
ii) 1965

Question 3.
The vivid explanation of the plate tectonic theory was given by-
i) W. J. Morgan
ii) J. T. Wilson
iii) Alfred Wegener
Answer:
i) W. J. Morgan.

Question 4.
Asthenosphere lies –
i) 500-600 km below the crust
ii) 300-400 Km below the crust
iii) 200-300 kmbelow the crust
iv) 100-200 Km below the crust.
Answer:
iv) 100-200 Km.

Question 5.
Krakatua volcano has become active after-
i) 200 years
ii) 400 ycars
iii) 500 years
iv) 300 years
Answer:
i) 200 years.

Question 6.
The percentage of active volcano in the earth-
i) 10%
ii) 15%
iii) 20%
iv) 30%
Answer:
ii) 15%

Question 7.
The percentage volcanocs of the world are located in the middle of the plate on hot spot About-
i) 2%
ii) 3%
iii) 5%
iv) 8%
Answer:
iii) 5%.

Question 8.
The focus of the earthquake is located at the depth of –
i) 50-100 Km
ii) 100-150 Km
iii) 150-300 Km
iv) 200-250 Km
Answer:
i) 50-100 Km.

Question 9.
San Francisco was almost completely destroyed in a devastating earthsuake in-
i) 1910
ii) 1912
iii) 1904
iv) 1906
Answer:
1906

Question 10.
Percentage of earthquakes on the earth occur in the Pacific belt
i) 60%
ii) 70%
iii) 20%
iv) 40%
Answer:
ii) 70%.

Question 11.
Every year the powerful volcanic activities in the continental area are more than-
i) 20
ii) 10
iii) 40
iv) 50
Answer:
iv) 50.

Question 12.
The eruption of mount Pole occured in-
i) 1906
ii) 1202
iii) 1908
iv) 1905
Answer:
i) 1906.

Question 13.
Enormous loss of life and property took place due to the eruption of Mount St Helen in-
i) 1975
ii) 1980
iii) 1991
iv) 1900
Answer:
ii) 1980.

Question 14.
At the time of eruption many people die for-
i) cancer
ii) asthma
iii) suffocation
Answer:
iii) suffocation.

State whether True or False : (1 mark for each question)

1. The earth crust is made up of 18 small plate.
2. The outer mantle is located 300-400 Km. deep under the earth crust.
a. The temperature of asthenosphere is 1500° C.
4. The fold mountains are called ‘Young’.
5. The tectonic plates moved on asthenosphere.
6. popa of Mayanmar is a active volcano.
7. Primary wave is the fastest seismic wave and reaches the earth’s surface before all other waves.
8. The interior of the earth is still very hot.
9. Example of old fold mountain is Rocky.
10. Volcanism and earthquake are examples of sudden earth novements.
Answer:
1. false
2. false
3. true
4. true
5 true.
6. false
7. true
8. true
9. false
10. true.

Fill in the blanks : (1 mark for each question)

1. The temperature of asthenosphere is _______.
2. ______ is the deepest trench of the earth.
3. The divergent plate margin is called _______ plate margin.
4. The mountains are formed more than ______ years ago.
5. When the magma flows on the earth crust it is called ______.
6. The mountains like Himalaya Alps are formed ______ lack years ago.
7. ______ of earth is active volcano.
8. _______ is an alternative source of energy.
9. The epicentre of earthquake is ______ km deep.
10. In year ______ earth quake occur in
11. In 1906 the magnitude of the earthquake was _______.
12. ______ city was destructed in earthquake.
13. Earthquake takes place in earth at _________.
14. _____people had lost their life in Tsunami.
15. Damage and destruction was caused in ______ countries of South-East Asia.
16. On 26th January 2001 in _______ of Gujarat almost one lakh people lost their lives for severe earthquake.
17. Sudden of ______ earth the houses are broken.
18. Most of the active _______surround Pacific ocean as a ring.
19. The ring of earthquake in India is generally _________.
20. The magnitude of earthquake is measured by _________.
21. From the epicentre of the earthquake two types of wave spread out along the _____
22. Almost each and every ______ is earthquake prone.
23. Most of the focus of the earth quake located at the depth of _______ km.
24. ________ of N.ars is the highest voleanoes of the solar system.
25. A type of dense viscous lava comes out from the volcanoes of Indonesia which is known as _____ in Hawaiean language.
Answer:
1. 1500° C
2. Mariana
3. constructive
4. 3 – 4 millions of years
5. lava
6. 40
7. 15% Neutron
8. Geothermal energy
9. 50-100
10. 1955 kolce of Japan
11. 8.5
12. Sunfrancisco
13. 20%
14. 36000
15. 111
16. Bhuj
17. temor
18. Volcanoes
19. Himalaya mountain region
20. Seismograph
21. earth crust
22. margin of the plate
23. 50-100
24. Olympus Mars.
25. Aa.

Match the column A with column B.

Columu A	Column B
a. There are 6 major	i. at a rate of 10 cm/year
b. The earth’s crust is made of	ii. occur in Pacific Ring of Fire
c. Sometimes two plates move towards	iii. and 20 minor plates
d. Pacific Ocean plate is moving	iv. cannot be forecasted
e. The interior of the earth	v. due to an earthquake
f. 70 percent of all earthquake on the earth	vi. each other and collide
g. Unlike other natural disasters, an eartquake	vii. a few rigid and solid plates
h. Sometimes coastal land may be submerged	viii. is still very hot

Answer:
a) There are 6 major and 20 minor plates.
b) The earth’s crust is made of a few rigid and solid plates.
c) Sometimes two plates move towards each other and collide.
d) Pacific Ocean plate is moving at a rate of 10 cm / year.
e) The interior of the earth is still very hot.
f) 70 percent of all earthquake on the earth occur in Pacific Ring of Fire.
g) Unlike other natural disasters an eartquake cannot be forecasted.
h) Sometimes coastal land may be submerged due to an earthquake.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
Which scientist introduced the term ‘Plate’?
Answer:
In 1960 Canadian geophysicist – J. T. Wilson introduced the term ‘Plate’.

Question 2.
Who gave information on plate movement?
Ans:
In 1967 Mekensil and Parker gave information on Plate movement.

Question 3.
Who gave vivid explanation of the Plate tectonic theory?
Answer:
In 1967 W. J. Morgan and Le Pichon gave vivid explanation of the plate tectonic theory.

Question 4.
What is the deepest trench of the world? In which ocean does it lie?
Answer:
The deepest trench in the world is Mariana trench. It lies in Pacific ocean.

Question 5.
How is Alps mountain formed?
Four in one (viii)-24
Answer:
Alps mountain is formed when African and Eurasian plates converged to each other.

Question 6.
Name the main fold mountain of the world.
Answer:
Most of the fold mountains of the world have formed for convergence of the continental plates. These are Applachian Ural Aravalli etc

Question 7.
What is Volcanic mountain?
Answer:
The mountains those are formed by deposition of volcanic material is called volcanic mountain. Example-Fujiyama of Japan.

Question 8.
When did the volcanism start?
Answer:
Volcanism started millions of years ago?

Question 9.
In which countries volcanism have occured?
Answer:
Volcanism have occured in Japan Italy India Indonesia etc.

Question 10.
How is the ‘process affecting earth’s crust’ is classified?
Answer:
The process affecting earth’s crust is classified into the types – (i) Endogenetic process (ii) Exogenetic process.

Question 11.
What is lava?
Answer:
The melted viscous substance of the earth’s interior is called magma and when it comes out on the earth surface it is called lava.

Question 12.
Which is the highest volcano of the solar system?
Answer:
Olympus Mons of the Mars is the highest (27 Km) volcano of the solar system.

Question 13.
What percent volcano on the earth is active?
Answer:
15% volcanoes on the earth is active.

Question 14.
What is earthquake?
Answer:
When energy trapped in the blastic interior of the earth is suddenly released the earth crust experience temors which is called earthquake.

Question 15.
In which year devastating earthquake occured?
Ans:
Devastating earthquake occured in 2004 300000 lives were lost and enormous damage causc d over 11 countries in south east Asia.

Question 16.
What is Seismograph?
Answer:
A Seisomograph is the instrument measuring the magnitude of an earthquake.

Question 17.
In which year earthquake occured in Chili?
Answer:
In 1960 earthquake occured in Chili.

Question 18.
What was the level of the scale of the earthquake of Chili??
Answer:
The level of the level of the scale was 8.5.

Question 19.
At what percent the earthquakes occur in the Mid Continental Belt?
Answer:
20% earthquakes occur in the Mid Continental Belt.

Question 20.
Name the volcanoes of ‘Pacific Ring of Fire’?
Answer:
The volcanoes of Pacific Ring of Fire are Fujiyama (Japan) Pinatubo (Philippines), Krakatau (Indonesia) St. Helen (USA) Popocate peti (Maxico) Cotopaxi (Equador) ete.

Question 21.
What is the similarity between volcanism and earthquake?
Answer:
Volcanism and earthquake are both sudden manifestations of endogenetic forces.

Question 22.
What contribute to an area being more prone to disasters?
Answer:
Worldwide increase of population unplanned urbanization construction of heavy multistoried buildings roads dams and reserviors and illegitimate mining – all contribute to an area being more prone to disasters.

Question 23.
How can earthquake form natural harbour?
Answer:
Due to earthquake sometimes coastal land may be submerged due to an earthquake thereby forming an natural harbour.

Question 24.
Give an example where mud island emerged from under the water due to earthquake.
Answer:
A ‘mud island’ has emerged from under the water off the Karachi coast.

Long Questions & Answers : (3 marks for each question)

Question 1.
Write a short note on voleanism.
Answer:
From the time of the creation of the earth the volcanic erruption is occuring for millions of years. At the time of volcanic erruption the hot matter materials ash gases etc comes out from the openings of the earth. After frequent erraption lava is accumulated around the mouth of the volcano forming a cone shaped mountain. This type of mountain is called volcanic mountain as it is formed by deposition of the volcanic material. For example – Fujiyama of Japan Vesuvious of Italy Barren of India Krakatoa of Indonesia. In different geological time the temperature of earth’s atmosphere has been controlled by the process of volcanisation and finally has reached present favourable condition.

Question 2.
How volcanism takse place?
Answer:
The interior of the earth is still extremely hot. Naturallyb rocks are supposed to melt in 2000° C temperature at mantle. But for the extreme pressure of the upper layer the melting point is increased. Thus the rocks melts partly become slipping and flows like plastic. In some part of outer mantle the rocks melts completely. The density of the melted rock is lower. It is lighter than other partially melted rocks of the surrounding. The pressure and the melting point of magma decreases proportionally with the rising upward of magma. The liquid portion of magma turns into gas and water vapours under extreme pressure. Then the magma comes out to the earth’s surface through the opening of earth crust.

Question 3.
How is the earth quake formed?
Answer:
Almost all plate margin in the earth are highly earthquake prone and so all the volcanoes and the centres of earthquake are lie at same place. Besides natural causes like tectonic slides earthquake can also occurs from artificial or non natural causes like digging of underground pits mines and tannels construction of reservoirs and bomb explosion.

Question 4.
What is Contiuental Drift Theory?
Answer:
According to the continental Drift Theory of Alfred Wegener-about 300 million years ago all the present day landmasses were united as a supercontinunt called pangea. Later on it began to break apart and the pieces direted in different directions. Actually the continental crust was floating over oceanic crust. But the Continental Drift Theory could not fully explain the causes of earthquake or formation of oceans countries and mountains volcanism.

Question 5.
What is the divergent plate margła?
Answer:
When two oceanic plates move away from each other hot molton magma comes upward from the earth’s interior and new oceanic crust and mid oceanic ridges are formed from the hot molten magma after getting cooled and solidified. This is called divergent plate margin.

Question 6.
What is Mariana trench?
Answer:
For the moving towards of each other of continental and oceanic plate heavy oceanic plate get submerged under the continental plate. As the result deep oceanic trench is developed in this way. Mariana trench of the Pacific is the deepest trench of the world.

Question 7.
What is divastating plate margin?
Answer:
When the molten materials come out from the interior along the plate margins several volcanoes and volcanic islands are formed along the subduction plate margin. As the earth quake and earth movements are the regular phenomena in this areas of the crust. This type of plate margin is called divastating plate margin.

Question 8.
What is Seismic waves?
Answer:
Energy generated by an eartinquake spreads out in the form of waves from the focus and the epicenter to other parts of the earth just like the radial surge of waves after a stone is dropped on water. These waves are called Seismic waves.

Question 9.
Classify the Seismic waves?
Answer:
Seismic waves are of three types.
a) Primary wave : It is the fastest seismic wave (6 Km / sec) and reaches the earth’s surface before all other waves. This wave travels through solid liquid and gaseous media through a push and pull process.
b) Secondary wave : It reaches the earth’s surface immediately after the primary wave (3-5 Km . sec ). This wave can not travel through liquid and gaseous media. It travels only through solids.
c) Surface waves or level waves: Two types of this wave (3-4 Km / sec) spread out from the epicenter of the earthquake along the eart’s surface. These waves are responsible for most of the damages caused by eartquakes.

WBBSE Class 8 History Question Answer West Bengal Board

WBBSE Class 8 History Book Solutions West Bengal Board in English Medium

• Chapter 1 The Idea of History
• Chapter 2 Rise of Regional Powers
• Chapter 3 Establishing the Colonial Authority
• Chapter 4 The Nature of Colonial Economy
• Chapter 5 Reaction of Colonial Rule: Co-operation and Revolt
• Chapter 6 The Beginning of Nationalism
• Chapter 7 Nationalist Ideals and Their Evolution
• Chapter 8 From Communalism to the Partition
• Chapter 9 Constitution of India: Democratic Structure and Citizen’s Rights

WBBSE Class 8 History Book Solutions West Bengal Board in Hindi Medium

• Chapter 1 इतिहास परिचय
• Chapter 2 प्रादेशिक शक्तियों का उत्थान
• Chapter 3 औपनिवेशिक सत्ता की प्रतिष्ठा
• Chapter 4 औपनिवेशिक अर्थनीति का स्वरूप
• Chapter 5 औपनिवेशिक शासन का प्रभाव, सहयोग और विद्रोह
• Chapter 6 राष्ट्रीयतावाद का प्रारंभिक विकास
• Chapter 7 भारत के राष्ट्रीय आंदोलन का आदर्श और परिवर्तन
• Chapter 8 साम्प्रदायिकता के कारण देश का विभाजन
• Chapter 9 भारत का संविधान गणतंत्र की रूपरेखा और नागरिकों के अधिकार

WBBSE Class 8 Solutions

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 1 Interior of the Earth offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 1 Question Answer – Interior of the Earth

Textbook Page no. 1

Question 1.
What lies underneath the hard surface on which we stand?
Answer:
There are different things lies underneath the hard surface. They are gold mine, coal mine, hat spring volcanoes etc.

Question 2.
Has anybody ever seen the interior of the earth?
Answer:
It is not possible to see the interior of the carth. But we can somehow feel the warm water of hot spring, gold mine. coal mine and from that we can estitaate a bit what may be in the interior of the earth.

Question 3.
How much one has to dig up to see the centre of the earth?
Answer:
One has to dig up 6370 km to see the centre of the earth.

Question 4.
How far has it be possible to know the interior of the earth?
Answer:
It has become possible to guess how is the interior of the earth.

Question 5.
Why does density vary in different layers of the interior of the earth?
Answer:
The density of substances that lie near the centre more. At the time of the creation of the earth more dense and hot substances accumulate near the centre of the earth due to the gravitational force. Specially iron and nickel rotate around the centre of the earth. Comperatively lighter substances like aluminium and silicon come upword. Generally more we go near the centre of the earth more we feel the pressure extended by the materials. So as the pressure increases the density also increased. Thus the density varies in different layers of the interior of the earth.

Textbook Page no. 2

Question 1.
Why can we not go near the centre of the earth?
Answer:
It is not possible to dig up 6370 km to go near thic centre of the earth !

Question 2.
Why couid we not collect any information directly about the earth’s interior?
Answer:
We can not enter in the earth’s interior easily. So it is not possible to collect information about earth’s interior directly.

Textbook Page no. 6

Question 1.
Explain the convection current in asthenosphere with the help of simple experiment.
Answer:
The layer of asthenosphere is very weak. Substances of this layer are molten and soft in nature. Due to exsessive heat and pressure the rocks are here in a state of viscosity-just like melted asphalt or molasses. Comperatively light materials come upwards when heated geothermally, and allow the heavier one to go downward. Thus the convection current occurs in asthenosphere.

Question 2.
what is the difference between magma and lava?
Answer:
Magma: Magma is the melted and liquid form of mixture of gas and vapour due to excessive pressure and temperature of earth chamber.
Lava: Lava is the loot molten semiliquid magma that comes out through the opening of earth surface.

Question 3.
You have an idea about the exterior and interior of the earth Which one attracts you more and why?
Answer:
I like the exterior of the carth as it is possible to be observed and analyzed.

Class 8 Geography Chapter 1 Question Answer West Bengal Board – Interior of the Earth

Multiple Choice Questions & Answers : (1 mark for each question).

Question 1.
The core of the earth is almost-
i) 3500 km
ii) 5300 km
iii) 6300 km
ii) 3700 km
Answer:
i) 3500 km.

Question 2.
The average temperature of core is almost-
i) 3000°C
ii) 4060°C
iii) 5000°C
iv) 6000°C
Answer:
iii) 5000°C.

Question 3.
In between 30-700 km of the mantle is known as-
i) nifesima
ii) crofesima
iii) outer core
iv) inner core
Answer:
ii) crofesima

Question 4.
Concard discontinuity is lying-
i) above SIAL
ii) below SIM
iii) between SIAL and SIMA
iv) below SIAL
Answer:
iii) between SIAI, and SIMA

Question 5.
The temperature of mantle is-
i) 1000°-2000°
ii) 3000°-4000°C
iii) ii) 4000°-5000° C
iv) 2000°-3000°
Answer:
iv) 2000°-3000°C.

Question 6.
The upper layer of the earth’s crust is-
i) SIMA .
ii) SIAL
Answer:
ii) SIAL.

Question 7.
The outer most part of the earth is very-
i) thick
ii) thin
Answer:
ii) thin.

Question 8.
Greater part of the earth consists of –
i) Hydrogen
ii) Oxygen
ii) Nitrogen
Answer:
ii) Oxygen.

Question 9.
The density of the matter near the centre of the earth is-
i) more
ii) less
Answer:
i) more

Question 10.
The earth originated almost-
i) 640 crore years ago
ii) 540 crore years ago
iii) 460 crore years ago
Answer:
iii) 460 crore years ago

State wliether True or False : (1 mark for each question)

1. It is an casy task to collect information of earth’s interior.
2. Temperature in carth’s interior increases at the rate of abott 10°C / 33 meters depth.
3. Regarding to the earth’s depth 12 km depth is negligible..
4. Lava comes out through the hot spring.
5. There is a pool of fire in the interior of the carth.
6. Sometimes there are severe treamous due to tremendous cyclone.
7. There are few countries where the electricity is generated from geothermal energy.
8. The volume of the matter increases with the increasing of the temperature.
9. SIAL lies above SIMA or oceanic crust.
10. Conrad discontiunity is lying in between SIAL and SIMA.
11. Greater part of the earth crust consists of Silicon.
12. The rocks of the earth crust is rich in minerals.
13. 47% of earth crust is covered with oxygen.
14. Scientists have found only two layers in the earth interior.
15. Mantle lies below the crust.
Answer:
1. false
2. false
3. true
4. false
5. true
6. false
7. false
8. true
9. true
10. true
11. false
12. true
13. true
14. fale
15. true.

Fill in the blanks : (1 mark for each question)

1. The earth’s _______ is divided into layers.
2. Scientist have collected information regarding earth’s interior by matching the movement of the _______ .
3. _______ discontinuity line lies in between mantle and core.
4. The _______ encircles the inner core.
5. The two layers composed of different elements and varied density determind by _______.
6. _______ is lying in between SIAL and SIMA.
7. The radius of the earth is _______ km.
8. The distance between earth-surface and the _______ is 6370 km.
9. World’s decpest gold mine located in _______ Africa is only 3-4 km deep.
10. Sometime the earth shakes for tremendous _______ .
11. The earth has been created almost _______ years ago.
12. Hot semi-liquid comes out through the mouth of _______ .
13. Hot spring is found at _______ in West Bengal.
14. _______ is one type of energy.
15. In many countries of the world _______ is genereted from heat energy.
16. _______ lulfils their 30% demand of electircity from geothermal energy.
17. The _______ generates more electricity from geothermal energy in the world.
18. The using of _______ can be reduced by using thermal energy to produce electricity.
19. The average density of the matter is _______ gram / cubic cm near the centre of the earth.
20. In respect of _______ satellites average density of the earth is 5.5 gram / cubic c m.
21. Theof _______ the matter near the centre of the earth is more.
22. _______ matter always precipitates underneath.
23. Light matters _______ upwards.
24. During the origin of the earth the very hot and denser matters move towards the earth’s centre due to _______ pull.
25. Especially ________ and Nickel start rotating the centre of the earth.
26. In general to pressure of _______ increases with the increase of depth towards earth’s interior.
27. Earth’s _____ is divided into layers of varied densities and characteristics.
28. Scientists have collected information regarding earth’s interior by watching the movement of the seismic ______.
29. The average depth of the carth’s crust is ____ km below the occeans and _____ km beneath the continents.
30. _______ lies over the SIMA or ocennic crust.
31. _______ of the crust are rich in various minerals.
32. _______ lies at the top of the crust.
Answer:
1. interior
2. seismic waves
3. gutenberg
4. Outer core
5. discontinuity line
6) Conrad discontiunity
7. 6700 km
8. core
9. South
10. earth quake
11. 460
12. Volcano
13. Bakreswar
14. Geo-thermal heat
15. electricity
16. Iceland
17, United States of America
18. fossil fuel
19. 11
20. artificial
21. density
22. Heavy
23. float
24. gravitational
25. iron
26. matters
27. interior
28. waves
29. 5 km and 60 km
30. SIAL
31. Rocks
32. Sail.

Match the following : (1 mark for each question)

a) Match the column A with column B.

Column A	Column B
a) Moho lies between	i) into layers like an onion
b) Uppermost layer is compared	ii) out of the carth’s interior
c) Conrad discontinuity	iii) near the surface
d) Earth’s interior is divided	iv) $5100 \mathrm{~km}$ to $6370 \mathrm{~km}$ deep
e) In hot springs boiling water emerges	v) the crust aud the mantle
f) Lighter elements float upward	vi) is between SIAL and SIMA
g) The inner core is nearly	vii) axis of the earth in semi-solid state
h) The outer core rotates around the	viii) with the skin of sn apple

Answer:
a) Moho lies between the crust and the mantle.
b) Uppermost layer is compared with the skin of sn apple.
c) Conrad discontinuity is between SIAL and SIMA.
d) Earth’s interior is divided into layers like an onion.
e) In hot springs boiling water emerges out of the earth’s interior.
f) Lighter elements float upward near the surface.
g) The inner core is nearly 5100 km to 6370 km deep.
h) The outer core rotates around the axis of the earth in semi-solid state.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
What is the radius of the earth?
Answer:
The radius of the earth is 6370 km.

Question 2.
What is the distance between the surface and the core of the earth?
Answer:
6370 km. is the distance between the surface and the core of the earth.

Question 3.
What is the depth of the deepest mine of the world?
Answer:
The depth of the deepest mine of the world 3-4 km.

Question 4.
What is the rate of increasing temperature in the earth’s interior?
Answer:
The temperature in the earth’s interior increases at the rate of about 1°C / 33 meters depth,

Question 5.
Which is the artificial deepest hole of the world?
Answer:
The artificial deepest hole of the world is the hole in kala peninsula of north western Russia measuring a depth of 12 km.

Question 6.
What comes out from the hot spring?
Answer:
Hot water comes out from the hot spring.

Question 7.
What comes out form the mouth of the volcanoes?
Answer:
Hot molten semi-liquid lava comes out from the mouth of the volcano.

Question 8.
When was the earth created?
Answer:
The earth was created almost 460 crore years ago.

Question 9.
What sappens to the matter if the temperature is increased?
Answer:
On heating the solid matter converts into liquid and expands in volume.

Question 10.
Where in the earth the temperature and the pressure both are excessive?
Answer:
in the interior of the earth.

Question 11.
Where in West Bengal hot spring is situated?
Answer:
Hot spring is situated at Bakreswar of West Bengal.

Question 12.
What is called this type of water?
Answer:
This type of water is called ground water.

Question 13.
What is geo-thermal heat?
Answer:
Geo-thermal heat is one type of energy.

Question 14.
What can be generate from geo-thermal energy?
Answer:
Electricity can be generated from geo-thermal energy.

Question 15.
What percent of the demand of electricity is fulfilled from geo-thermal energy in Ireland?
Answer:
Almost 30%.

Question 16.
Which country of the world uses most amount of geo-thermal energy to generate electricity?
Answer:
The United States of America.

Question 17.
The use of which substance can be reduced by generating electricity by using geo-thermal energy?
Answer:
The use of fossil fuel can be reduced.

Question 18.
What is the average density of earth crust?
Answer:
Only 2.6 to 3.3 gram / cubic cm.

Question 19.
What is the average density of matter near the centre of the earth?
it Answer: Almost 11 gram / cubic cm.

Question 20.
What is the average density of earth in respect of artificial satellites?
Answer:
5.5 gram / cubic cm.

Question 21.
Which wave can not pass through liquid or semi liquid medium?
Answer:
S wave can not pass through liquid or semi liquid medium.

Question 22.
What is increased with the increasing of pressure on the matter?
Answer:
Density increases.

Question 23.
Which layer of earth is present just below the earth crust?
Answer:
Mantle is present just below the earth crust.

Question 24.
Who wrote the famous science fiction of earth?
Answer:
Jule Verne.

Question 25.
Where is the layer SIMA situated?
Answer:
SIMA situated beneath the ocean.

Question 26.
What does SIMA consist of ?
Answer:
The layer SIMA consists of Silicon (Si) and Magnesium (Mg).

Question 27.
What the SIMA made up of?
Answer:
It is made up of basalt like ignious rock.

Question 28.
Where is the layer SIAL situated?
Answer:
SIAL is situated above SIMA.

Question 29.
What is the uppermost layer of the eartherust?
Answer:
The uppermost layer of the earthcrust is Soil.

Question 30.
Which gas is present covering most of the part of earth crust?
Answer:
Oxygen.

Question 31.
What is the second element of earth crust?
Answer:
Silicon is the second element of earth crust.

Question 32.
Which line seperates the two different elements and density layers?
Answer:
Discontinuity line.

Question 33.
Which line presents in between SIAL and SIMA?
Answer:
conrad discontinuity.

Question 34.
What is the temperature of mantle?
Answer:
2000°-3000°C.

Question 35.
W ist are the tnain elements of mantle?
Answer:
Nickel Ctromium, Magnesium and Silicon.

Question 36.
What is the meaning of the word asthenosphere?
Answer:
weaker layer.

Question 37.
How thick is the core?
Answer:
The core is 3500 km. thick.

Question 38.
What is the average temperature of the core?
Answer:
Almost 5600°C.

Question 39.
What is the density of core?
Answer:
Almost 9.1 to 13.1 gram / cubic cm.

Question 40.
What is the depth of inner core?
Answer:
5100 km to almost 6370 km.

Question 41.
What is the depth of outer core?
Answer:
2900 km to almost 5100 km.

Question 42.
Which line present between the mantle and the core?
Answer:
Gutenberg discontinuity.

Short Questions & Answers : (2 marks for each question)

Question 1.
What is magma?
Answer:
Due to enormous pressure and temperature the substances of the earth’s interior remain liquid, being mixed with gas and vapour is called magma.

Question 2.
What is lava?
Answer:
When hot molten magma of the earth’s interior, comes out through the cracks and joints on the earth’s surface, it is called lava.

Question 3.
In what state the mattrers remain if the pressure and temperature both are excessive in the interior of the earth?
Answer:
If the temperature in the interior of the earth increases the matter melts into liquid and expands in volume. On the other hand with the increasing of the pressure the volume decreases.

Question 4.
What is Geo-thermal energy?
Answer:
Geo-thermal heat is one type of energy. The heat of the earth gradually transferred to the earth crust. This heat is ealled Geo-thermal energy.

Question 5.
What is density?
Answer:
Density is the measure of mass present in unit voiume of substance.

Question 6.
What is the Earth core?
Answer:
The innermost layer of the carth lies encircles the centre of the earth is known as the Earth core.

Question 7.
What is a NIFE?
Answer:
The layer of the mantle that made up of Nickel and Ferrum is known as NIFE.

Question 8.
How is the Earth core divided?
Answer:
The Earth core is divided into two parts (i) inner core and (ii) outer core.

Long Questions & Answers : (3 marks for each question)

Question 1.
What is Seismic waves?
Answer:
The scientists have collect information about the earth interior by watching the movement of the seismic wave. The seismic wave passes through different substances. Sometimes it is rapid sometimes it is slow. There are two types of waves. One is P and another is S. P wave can pass through either solid or liquid. But S wave can not pass through liquid or semi-liquid materials.

Question 2.
What do you know by the term ‘Inner core’?
Answer:
The layer of earth lies surrounding the centre of the earth is known as inner core; the depth of the layer is about 5100 km to 6370 km. This layer has the maximum amount of pressure, temperature and density. Due to very high pressure all the substances remain here in solid state.

Question 3.
What is the ‘Outer core’?
Answer:
The layer that encles the inner core is called the Outer core. The depth of the outer core is 2900 km to 5100 km. Pressure, temperature and density is comparatively lesser than inner core. It rotates around the axis of the earth in semi-liquid state. Being in a viscous state the ferrum in the layer develops an electro-magnetic field for very high velocity from which the magnetism of the earth is formed.

Question 4.
What is the ‘mantle’?
Answer:
Below the crust there is mantle. The temperature of the mantle is 2000,3009°C. Density is 3.4 to 5.6 gram / cube cm. The main elements of the layer are iron, silicon, chromium, nickel and magnesium.

WBBSE Class 8 Geography Question Answer West Bengal Board

WBBSE Class 8 Geography Book Solutions West Bengal Board in English Medium

• Chapter 1 Interior of the Earth
• Chapter 2 Unstable Earth
• Chapter 3 Rocks
• Chapter 4 Pressure Belts and Winds
• Chapter 5 Cloud and Rain
• Chapter 6 Climatic Regions
• Chapter 7 Human Activities and Environmental Degradation
• Chapter 8 Some Neighbouring Countries of India and Its Relationship with Them
• Chapter 9 North America
• Chapter 10 South America
• Chapter 11 Oceania

WBBSE Class 8 Geography Book Solutions West Bengal Board in Hindi Medium

• Chapter 1 पृथ्वी का आंतरिक भाग
• Chapter 2 परिवर्तनशील पृथ्वी
• Chapter 3 चट्टान
• Chapter 4 चापवलय और वायु प्रवाह
• Chapter 5 मेघ – वर्षा
• Chapter 6 जलवायु क्षेत्र
• Chapter 7 मनुष्य के कार्य-व्यापार एवं परिवेश का ह्रास
• Chapter 8 भारत के पड़ोसी देश और उनके साथ संबंध
• Chapter 9 उत्तरी अमेरिका
• Chapter 10 दक्षिणी अमेरिका
• Chapter 11 ओशोनिया

WBBSE Class 8 Solutions