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.