NCERT Solutions for Chapter 4 Air Class 7 Geography
Book Solutions
1(i)
Answer the following questions.
(i) What is atmosphere?
Answer
The earth is surrounded by a huge blanket of air called atmosphere.
Exercises
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1(ii)
Answer the following questions.
Which two gases make the bulk of the atmosphere?Answer
Nitrogen and oxygen make the bulk of the atmosphere.
Exercises
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1(iii)
Answer the following questions.
Which gas creates green house effect in the atmosphere?
Which gas creates green house effect in the atmosphere?
Answer
Carbon dioxide creates the greenhouse effect in the atmosphere.
Exercises
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1(iv)
Answer the following questions.
What is weather?
What is weather?
Answer
Weather is short-term state of the atmosphere whether it is hot or cold, wet or dry. It is the hour to hour, day to day condition of the atmosphere.
Exercises
Page Number 27
1(v)
Answer the following questions.
Name three types of rainfall?
Name three types of rainfall?
Answer
Three types of rainfall are:
(i) Convectional rainfall
(ii) Orographic rainfall
(iii) Cyclonic rainfall
(i) Convectional rainfall
(ii) Orographic rainfall
(iii) Cyclonic rainfall
Exercises
Page Number 27
1(vi)
Answer the following questions.
What is air pressure?
What is air pressure?
Answer
The pressure exerted by the weight of air on the surface of the earth is called air pressure.
Exercises
Page Number 27
2(i)
Tick the correct answer.
Which of the following gases protects us from harmful sun rays?
(a) Carbon dioxide
(b) Nitrogen
(c) Ozone
(a) Carbon dioxide
(b) Nitrogen
(c) Ozone
Answer
✓ (c) Ozone
Exercises
Page Number 27
2(ii)
Tick the correct answer.
The most important layer of the atmosphere is(a) Troposphere
(b) Thermosphere
(c) Mesosphere
Answer
✓ (a) Troposphere
Exercises
Page Number 27
2(iii)
Tick the correct answer.
Which of the following layers of the atmosphere is free from clouds?(a) Troposphere
(b) Stratosphere
(c) Mesosphere
Answer
✓ (b) Stratosphere
Exercises
Page Number 27
2(iv)
Tick the correct answer.
As we go up the layers of the atmosphere, the pressure(a) Increases
(b) Decreases
(c) Remains the same
Answer
✓ (b) Decreases
Exercises
Page Number 27
2(v)
Tick the correct answer.
When precipitation comes down to the earth in the liquid form, it is called(a) Cloud
(b) Rain
(c) Snow
Answer
✓ (b) Rain
Exercises
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3
Match the following.
(i) Trade Winds | (a) Incoming solar energy |
(ii) Loo | (b) Seasonal wind |
(iii) Monsoon | (c) Horizontal movement of Air |
(iv) Wind | (d) Layer of ozone gas |
- | (e) Permanent wind |
- | (f) Local wind |
Answer
(i) Trade Winds | (e) Permanent wind |
(ii) Loo | (f) Local wind |
(iii) Monsoon | (b) Seasonal wind |
(iv) Wind | (c) Horizontal movement of Air |
Exercises
Page Number 27
4(i)
Give reasons.
Wet clothes take longer time to dry on a humid day?
Answer
In humid day, the humidity is very high that is the level water vapour in atmosphere is high. Due to this, air is not able carry away more water vapour with it and thus the clothes take longer time to dry on a humid day.
Exercises
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Exercises
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