Class 7 Geography – Chapter 4: Air
Air is an important chapter in Class 7 Geography that explains the atmosphere and its role in supporting life on Earth. This chapter helps students understand the composition and layers of the atmosphere, weather and climate, air pressure, winds, and different types of rainfall.
In this post, you will find complete Question–Answer solutions for Class 7 Geography Chapter 4 – Air (NCERT/JKBOSE) written in simple and easy language for quick understanding and memorization. The answers are clear, exam-oriented, and useful for revision and concept building. Students can read the notes online or use them for quick preparation before exams.
Exercise Questions
1. Answer the following questions.
(i) What is atmosphere?
(ii) Which two gases make the bulk of the atmosphere?
(iii) Which gas creates greenhouse effect in the atmosphere?
(iv) What is weather?
(v) Name three types of rainfall?
(vi) What is 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
(ii) The most important layer of the atmosphere is
(a) Troposphere
(b) Thermosphere
(c) Mesosphere
(iii) Which of the following layers of the atmosphere is free from clouds?
(a) Troposphere
(b) Stratosphere
(c) Mesosphere
(iv) As we go up the layers of the atmosphere, the pressure
(a) Increases
(b) Decreases
(c) Remains the same
(v) When precipitation comes down to the earth in liquid form, it is called
(a) Cloud
(b) Rain
(c) Snow
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
4. Give reasons.
(i) Wet clothes take longer time to dry on a humid day.
(ii) Amount of insolation decreases from equator towards poles.
Answers
1.
(i) The atmosphere is the blanket of gases that surrounds the Earth. It provides air for living beings and protects the planet from harmful solar radiation.
(ii) The two gases that make up most of the atmosphere are Nitrogen (78%) and Oxygen (21%).
(iii) Carbon dioxide is the gas mainly responsible for the greenhouse effect in the atmosphere because it traps heat.
(iv) Weather is the day-to-day condition of the atmosphere at a particular place, including temperature, rainfall, wind, and humidity.
(v) The three main types of rainfall are:
• Convectional rainfall
• Orographic (relief) rainfall
• Cyclonic rainfall
(vi) Air pressure is the pressure exerted by the weight of air on the Earth’s surface. It decreases as we go higher in the atmosphere.
2.
(i) c) Ozone
(ii) a) Troposphere
(iii) b) Stratosphere
(iv) b) Decreases
(v) b) Rain
3.
(i) Trade Winds — Permanent wind
(ii) Loo — Local wind
(iii) Monsoon — Seasonal wind
(iv) Wind — Horizontal movement of air
4.
(i) Wet clothes take longer to dry on a humid day because the air already contains a lot of moisture. This slows down evaporation.
(ii) The amount of insolation decreases from the equator to the poles because the Sun’s rays fall directly at the equator but reach the poles at a slanting angle, spreading the energy over a larger area.
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