Page 1
NCERT
SOLUTIONS
CLASS - 7TH
aglase .co
Page 2
Book : Our Environment Ncert Solutions | Chapter-4 Geography
Class : 7th
Subject : Geography
Chapter : 4
Chapter Name : Air
Q1 For ten days note down weather report from a local newspaper and observe the
changes occurring in the weather.
Answer. DIY
Page : 23 , Block Name : Let’s do
Q1 Answer the following questions.
(i) What is atmosphere?
(ii) Which two gases make the bulk of the atmosphere?
(iii) Which gas creates green house effect in the atmosphere?
(iv) What is weather?
(v) Name three types of rainfall?
(vi) What is air pressure?
Answer. (i) The huge blanket of air surrounding the Earth is called atmosphere.
(ii) Nitrogen and oxygen make the bulk of the atmosphere.
(iii) Carbon dioxide creates greenhouse effect in the atmosphere.
(iv) Weather refers to the short-term changes in the atmosphere. It is the hour-to-hour,
day-to-day condition of the atmosphere.
(v) Convectional rainfall, orographic rainfall and cyclonic rainfall are the three types of
rainfall.
(vi) Air pressure is de�ned as the pressure exerted by the weight of air on the Earth’s
surface.
Page : 27 , Block Name : Exercise
Q2 Tick the correct answer.
(i) Which of the following gases protects us from harmful sun vays?
(a) Carbon dioxide (b) Nitrogen (c) Ozone
(ii) The most important layer of the atmosphere is
(a) Troposphere (b) Thermosphere (c) Mesosphere
Page 1 of 7 Aglasem Schools
Page 3
Book : Our Environment Ncert Solutions | Chapter-4 Geography
(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 the liquid form, it is called
(a) Cloud (b) Rain (c) Snow
Answer.
Page : 27 , Block Name : Exercise
Q3 Match the following.
Answer.
Page 2 of 7 Aglasem Schools
Page 4
Book : Our Environment Ncert Solutions | Chapter-4 Geography
Page : 27 , Block Name : Exercise
Q4 Give reasons.
(i) Wet clothes take longer time to dry on a humid day?
(ii) Amount of insolation decreases from equator towards poles?
Answer. (i) Things remain damp and wet, and take longer time to dry when the
atmosphere around them is damp and wet. Humidity is the amount of moisture or water
vapour present in air at any moment in time. On a humid day, the air is full of water
vapour. As the air gets warmer, its capacity to hold the water vapour increases. As a
result, conditions become more and more humid. Hence, wet clothes take longer time to
dry on a humid day.
(ii) Insolation refers to the incoming solar radiations intercepted by the Earth. The
amount of sunlight received by the regions close to the Equator is greater than the
amount of sunlight received by the regions close to the Poles. This is because of the tilt
of the Earth’s axis. As a result of this tilt, the incoming solar radiations cover a greater
area at the Equator than at the Poles.
Page : 27 , Block Name : Exercise
Q5 For fun.
(i) Solve this Crossword puzzle with the help of given clues:
Page 3 of 7 Aglasem Schools
Page 5
Book : Our Environment Ncert Solutions | Chapter-4 Geography
Page 4 of 7 Aglasem Schools
Page 6
Book : Our Environment Ncert Solutions | Chapter-4 Geography
(ii) Make a weather calendar for one week. Use pictures or 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 example is given below:
Answer. (i)
Page 5 of 7 Aglasem Schools
Page 7
Book : Our Environment Ncert Solutions | Chapter-4 Geography
(ii) Your weather calendar could look like this.
Page 6 of 7 Aglasem Schools
Page 8
Book : Our Environment Ncert Solutions | Chapter-4 Geography
Page : 28 , Block Name : Exercise
Page 7 of 7 Aglasem Schools