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NCERT Solutions for Class 8 Geography Chapter 4 - Air

Q1. Answer the following questions.

(i) What is atmosphere? 
Ans: The earth is surrounded by a huge blanket of air called atmosphere.

AtmosphereAtmosphere

(ii) Which two gases make the bulk of the atmosphere?
Ans: Nitrogen and oxygen make the bulk of the atmosphere.

(iii) Which gas creates green house effect in the atmosphere? 
Ans: Carbon dioxide creates the greenhouse effect in the atmosphere.

(iv) What is weather? 
Ans: 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?
Ans: Three types of rainfall are:
(i) Convectional rainfall
(ii) Orographic rainfall
(iii) Cyclonic rainfall

(vi) What is air pressure? 
Ans: The pressure exerted by the weight of air on the surface of the earth is called air pressure.


Q2. Tick the correct answer.

(i) Which of the following gases protects us from harmful sun rays? 
(a) Carbon dioxide
(b) Nitrogen
(c) Ozone
Ans: (c)

(ii) The most important layer of the atmosphere is 
(a) Troposphere
(b) Thermosphere
(c) Mesosphere
Ans: (a)

(iii) Which of the following layers of the atmosphere is free from clouds?
(a) Troposphere
(b) Stratosphere
(c) Mesosphere
Ans: (b)

(iv) As we go up the layers of the atmosphere, the pressure 
(a) Increases
(b) Decreases
(c) Remains the same
Ans: (b)

(v) When precipitation comes down to the earth in the liquid form, it is called 
(a) Cloud 
(b) Rain 
(c) Snow 
An: (b)


Q3. 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

Ans:

(i) Trade Winds

(e) Permanent wind

(ii) Loo

(f) Local wind

(iii) Monsoon

(b) Seasonal wind

(iv) Wind

(c) Horizontal movement of Air


Q4. Give reasons. 

(i) Wet clothes take longer time to dry on a humid day? 
(ii) Amount of insolation decreases from equator towards poles? 
Ans: (i) 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.
Humid DayHumid Day

(ii) Insolation is the incoming 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, amount of insolation decreases from equator towards poles.

The document NCERT Solutions for Class 8 Geography Chapter 4 - Air is a part of the Class 7 Course Social Studies (SST) Class 7.
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FAQs on NCERT Solutions for Class 8 Geography Chapter 4 - Air

1. What is air pollution?
Ans. Air pollution is the presence of harmful substances in the air that we breathe. These substances can include gases, smoke, dust, and other particles that can be hazardous to human health and the environment.
2. What are the major sources of air pollution?
Ans. The major sources of air pollution are industrial emissions, transport emissions, burning of fossil fuels, and agricultural activities. Natural events such as wildfires and volcanic eruptions also contribute to air pollution.
3. How does air pollution affect human health?
Ans. Air pollution can have serious health effects on humans, including respiratory problems, cardiovascular disease, and even cancer. It can also cause irritation of the eyes, nose, and throat, and can worsen existing conditions such as asthma.
4. What are some solutions to reduce air pollution?
Ans. Some solutions to reduce air pollution include using clean energy sources such as solar and wind power, reducing the use of fossil fuels, increasing public transportation, and implementing stricter regulations on industrial emissions.
5. What can individuals do to help reduce air pollution?
Ans. Individuals can help reduce air pollution by using public transportation, walking or biking instead of driving, reducing energy consumption in their homes, and properly disposing of hazardous waste. They can also support policies and initiatives that promote cleaner air and a healthier environment.
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