NCERT Solutions for Class 7 Geography Chapter 4 Air

NCERT Solutions for Class 7 Geography Chapter 4 Air Social Science

NCERT Solutions for Class 7 Geography Chapter 4 Air are given on this page will provide you with adequate time to research and work on their assignments. These free NCERT Solutions are prepared just for you according to the latest CBSE guidelines. So, you will be able to score excellent marks in this assessment. Students get the chance to double check their answers and learn how well they're grasping what they need to know.

Chapter 4 Air NCERT Solutions for Class 7 Geography

1. Answer the following questions.

(i) What is atmosphere? 

Solution

The earth is surrounded by a huge blanket of air called atmosphere.

(ii) Which two gases make the bulk of the atmosphere?

Solution

Nitrogen and oxygen make the bulk of the atmosphere.

(iii) Which gas creates green house effect in the atmosphere? 

Solution

Carbon dioxide creates the greenhouse effect in the atmosphere.

(iv) What is weather? 

Solution

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.

(v) Name three types of rainfall?

Answer 

Three types of rainfall are:

(i) Convectional rainfall 

(ii) Orographic rainfall 

(iii) Cyclonic rainfall

(vi) What is air pressure? 

Solution

The pressure exerted by the weight of air on the surface of the earth is called air pressure.

2. Tick the correct answer.

(i) Which of the following gases protects us from harmful sun rays?

(a) Carbon dioxide

(b) Nitrogen

(c) Ozone

Solution (c) Ozone

(ii) The most important layer of the atmosphere is

(a) Troposphere

(b) Thermosphere 

(c) Mesosphere 

Solution (a) Troposphere

(iii) Which of the following layers of the atmosphere is free from clouds?

(a) Troposphere 

(b) Stratosphere

(c) Mesosphere

Solution (b) Stratosphere

(iv) As we go up the layers of the atmosphere, the pressure 

(a) Increases 

(b) Decreases 

(c) Remains the same 

Solution (b) Decreases

(v) When precipitation comes down to the earth in the liquid form, it is called 

(a) Cloud 

(b) Rain 

(c) Snow

Solution (b) Rain

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

Solution

(i) Trade Winds	(e) Permanent wind
(ii) Loo	(f) Local wind
(iii) Monsoon	(b) Seasonal wind
(iv) Wind	(c) Horizontal movement of Air

4. Give reasons. 

(i) Wet clothes take longer time to dry on a humid day?

Solution

On a humid day the air is full of water vapour. Hence, evaporation is very slow. This is the reason why wet clothes take longer time to dry on a humid day.

(ii) Amount of insolation decreases from equator towards poles?

Solution

Insolation is the solar energy intercepted by the Earth. Sunlight falls almost vertically on the equator whereas it falls at some angle on the poles. Due to this, there is less insolation in the northern hemisphere than in the southern hemisphere.