NCERT Solutions Class 7th Geography Social Science Chapter- 4 Air Question & Answer

Textbook	NCERT
Class	Class 7^th
Subject	Geography Social Science
Chapter	Chapter – 4
Chapter Name	Air
Category	Class 7th Social Science Geography
Medium	English
Source	Last Doubt

NCERT Solutions Class 7th Geography Social Science Chapter- 4 Air Question & Answer What is this air? What is our air made up of? What is the important of air? Why is air called? What is air full form? What is a air ? What is air in studies? What is air in easy language? What is air and types? What is air for 1 class? What are 10 uses of air? What is air ? What is air and example? What is a air ?What is air for kids? Why air pollution? How to stop air pollution? What are 4 types of pollution? What are the 4 types of air pollution?

Answer the following questions briefly.

Question. 1. What is atmosphere?

Answer- Atmosphere is a thin blanket of air that surrounds the earth. It protects us from the harmful rays of the sun. It consists of several gases in which nitrogen and oxygen occupy the major portion.

Question. 2. Which two gases make the bulk of the atmosphere?

Answer- Nirtrogen (78%) and oxygen (21%) make the bulk of the atmosphere.

Question. 3. Which gas creates greenhouse effect in the atmosphere?

Answer- Carbon dioxide creates a greenhouse effect in the atmosphere.

Question. 4. What is weather?

Answer- Weather is the hour-to-hour, day-to-day condition of the atmosphere.

Question. 5. Name three types of rainfall?

Answer-

Convectional rainfall
Orographic rainfall
Cyclonic rainfall.

Question. 6. What is air pressure?

Answer- The pressure exerted by the weight of air on the earth’s surface is known as air pressure.

Question. 2. Tick the correct answer:

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

(a) Carbon dioxide
(b) Nitrogen
(c) Ozone.

Answer- c) Ozone.

(ii) The most important layer of the atmosphere is

(a) Troposphere
(b) Thermosphere
(c) Mesosphere.

Answer- (a) Troposphere

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

(a) Troposphere
(b) Stratosphere
(c) Mesosphere.

Answer- (b) Stratosphere

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

(a) Increases
(b) Decreases
(c) Ramains the same.

Answer- (b) Decreases

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

(a) Cloud
(b) Rain
(c) Snow.

Answer- (b) Rain

Question. 3. Match the skill:

Column A	Column B
(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-

Column A	Column B
(i) Trade winds	(e) Permanent wind
(ii) Loo	(f) Local wind
(iii) Monsoon	(b) Seasonal wind
(iv) Wind	(c) Horizontal movement of air

Question. 4. Give reasons:

Wet clothes take longer time to dry on a humid day.
Amount of insolation decreases from equator torwards poles?

Answer – (1) As the air gets warmer its capacity to hold moisture, increases. Therefore it becomes more and more humid. On such days water from clothes or sweat from our body does not evaporate easily. Thus wet clothes take a longer time to dry.

• On the equator, insolation comes through vertical rays.
• It covers up less space. Hence heat is felt more.

(2) From the equator, it goes on coming through slanting rays. Slanting rays come on the earth passing longer distances through the atmosphere. They heat up more space. Hence there is less heat on a point of space.

Question. 5. For Fun
(1) Solve this crossword puzzle with the help of given clues:

Across

Down

6. An Indian tree having extraordinary quality of providing oxygen round the clock
8. Gas present in atmosphere occupying only 0.03% by volume
11. Outermost layer of atmosphere
12. Mixture of many gases
14. Life giving gas
15. Air in motion
16. An indian tree valued highly for medicinal properties
18. Gas protecting us from harmful sunrays
19. Low pressure area

1.Amount of water vapour in air
2.Condensation of water vapour around dust particles in atmosphere
3.Example of local wind blowing in summer in northern India
4.Short term changes in atmosphere
5.Precipitation in liquid form
7.Blanket of air around the earth
9.Instrument of measure pressure
10.Incoming solar radiation
13.Reduces visibility in winters
17.It is…..time when sun is overhead

Answer-

(ii) Make a weather calender for one week. Use pictures on symbols to show different types of weather. You can use more than one symbol in a day, if the weather changes. For example the sun comes out when .rain stops. An exmaple is given below: