Ncert Solutions Class 7 Geography Air
NCERT Solutions Class 7 Geography Chapter 4 Air
NCERT Solutions Class 7 Geography Chapter 4 Air: National Council of Educational Research and Training Class 7 Geography Chapter 4 Solutions – Air. NCERT Solutions Class 7 Geography Chapter 4 PDF Download.
NCERT Solutions Class 7 Geography Chapter 4: Overview
| Board | NCERT |
| Class | 7 (Seven) |
| Subject | Social Science |
| Book Name | Geography |
| Chapter | 04 (Four) |
| Chapter Name | Air |
| Topic | Exercise Solutions |
NCERT Solutions Class 7 Geography Chapter 4 – Air
1.) Answer the following questions.
(i) What is atmosphere?
Answer
Huge blanket of air surrounding the Earth is called atmosphere. It provides us with the air we breathe and protects us from the harmful effects of the sun's rays so the living beings on this earth depend on the atmosphere for their survival.
The layers of atmosphere are the troposphere, the stratosphere, the mesosphere and the thermosphere
(ii) Which two gases make the bulk of the atmosphere?
Answer
The two gases are
- Nirtrogen (78%)
- Oxygen (21%)
(iii) Which gas creates green house effect in the atmosphere?
Answer
The increased volume of carbon dioxide in the atmosphere causes green house effect.
(iv) What is weather?
Answer
The environment conditions changes it's temperature (hot or cold, wet or dry, calm or stormy, clear or cloud ) from time to time is called weather.
(v) Name three types of rainfall?
Answer
The three types of rainfall are
- Convectional rainfall
This rainfall occurs when the temperature gets high and the warmer air rises up in the atmosphere
- Relief (Orographic) rainfall
Rain formed when the air cools as it rises over hills or mountains.
- Cyclonic rainfall
Rain formed when warm and cold air meets each other.
(vi) What is air pressure?
Answer
The pressure exerted by the weight of air on the earth's surface is called air pressure. Air pressure is highest at sea level and decreases with the height.
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
Explanation: The ozone gas filters out most of the sun's ray( UV radiation) and protect us.
(ii) The most important layer of the atmosphere is
(a) Troposphere (b) Thermosphere (c) Mesosphere
Answer
a) Troposphere
Explanation: It contains 75% of all air in the atmosphere and the water vapour is found here so it's the most important layer of the atmosphere.
(iii) Which of the following layers of the atmosphere is free from clouds?
(a) Troposphere (b) Stratosphere (c) Mesosphere
Answer
(b) Stratosphere
Explanation: It is because it extends up to a height of 50 km and at such height its ideal for Airplanes to fly.
(iv) As we go up the layers of the atmosphere, the pressure
(a) Increases (b) Decreases (c) Remains the same
Answer
(b) Decrease
Explanation: This is because the air pressure is highest at sea level and decreases with height.
(v) When precipitation comes down to the earth in the liquid form, it is called
(a) Cloud (b) Rain (c) Snow
Answer
(b) Rain
The water which falls down as water drops is called rain.
3.) Match the following.
(i) Trade Winds – (e) Permanent wind.
(ii) Loo – (f) Local wind.
(iii) Monsoon – (b) Seasonal wind.
(iv) Wind – (c) Horizontal movement of Air.
Ncert Solutions Class 7 Geography Air
Source: https://www.netexplanations.com/ncert-solutions-class-7-geography-chapter-4-air/