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Important Questions for CBSE Class 7 Science Our Environment Chapter 4 - Air

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Last updated date: 27th Mar 2024
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CBSE Class 7 Science Our Environment Chapter 4 Air Important Questions - Free PDF Download

CBSE Class 7 Social Science Chapter 4 Our Environment Air is a crucial chapter that teaches the students about the different aspects of the environment. To study and use the concepts well, download and solve the important questions framed by the experts of Vedantu. Learn how to solve these questions by following the solutions given and sharpen your answering skills.

Free PDF download of Important Questions with solutions for CBSE Class 7 Social Science Our Environment Chapter 4 - Air prepared by expert Social Science teachers from latest edition of CBSE (NCERT) books. Register online for Social Science Our Environment tuition on Vedantu.com to score more marks in your examination.


Download CBSE Class 7 Social Science Geography Our Environment Important Questions 2023-24 PDF

Also, check Class 7 Social Science Geography Our Environment Important Questions for other chapters:

CBSE Class 7 Social Science Geography Our Environment Important Questions

Sl.No

Chapter No

Chapter Name

1

Chapter 1

Chapter 1 - Environment

2

Chapter 2

Chapter 2 - Inside Our Earth

3

Chapter 3

Chapter 3 - Our Changing Earth

4

Chapter 4

Chapter 4 - Air

5

Chapter 5

Chapter 5 - Water

6

Chapter 6

Chapter 6 - Natural Vegitation and Wildlife

7

Chapter 7

Chapter 7 - Human Environment - Settlement, Transport And Communication

8

Chapter 8

Chapter 8 - Human Environment Interactions

9

Chapter 9

Chapter 9 - Life in The Deserts

Study Important Questions Class 7 Social Science Our Environment Chapter 4 - Air

Very Short Answer Questions:                                                                    1 Mark

1. Fill in the blanks:

i. The ____ contains the gases which sustain life on this planet.

Ans: The troposphere contains the gases which sustain life on this planet.


ii. The ____ is free of clouds. 

Ans: The stratosphere is free of clouds.


iii. As we go up the layers of the atmosphere, the temperature _____. 

Ans: As we go up the layers of the atmosphere, the temperature decreases.


iv. When clouds condense and fall down in liquid form, it is called ___. 

Ans: When clouds condense and fall down in liquid form, it is called rain.


2. State true and false:

i. Bulk of the atmosphere is made from 78% nitrogen and 21% oxygen.

Ans: True


ii. The atmosphere provides protection to the earth and sustains life on the planet.

Ans: True


iii. Weather changes on an hourly basis.

Ans: True


iv. Air pressure exerts pressure on the moon.

Ans: False


3. Match the following:

Trade winds

Seasonal wind

Monsoon

Horizontal movement of air

Winds

Local wind

Loo

Permanent wind


Ans:

Trade winds

Permanent wind

Monsoon

Seasonal wind

Winds

Horizontal movement of air

Loo

Local wind


4. Choose the correct option:

i. _____ protects from the harmful sun rays. 

  1. Carbon dioxide

  2. Ozone 

  3. Nitrogen

  4. Oxygen

Ans: (b) Ozone


ii. _____ is the most important layer of the earth.

  1. Thermosphere

  2. Troposphere

  3. Mesosphere

  4. Stratosphere

Ans: (b) Troposphere


5. Define the following:

i. Monsoon 

Ans: Monsoon is a seasonal wind that blows over the Indian Ocean. It results in huge rainfall in the Indian subcontinent. It begins in June.


ii. Wind

Ans: A wind can be defined as the horizontal flow of air from a region with high pressure to a region with low pressure. The difference in air pressure causes this movement of the air.


Short Answer Questions: 2 Marks

6. What is the definition of atmosphere?

Ans: The atmosphere can be defined as follows:

  • The atmosphere is a massive blanket of air surrounding the earth.

  • It is composed of several gases like nitrogen, oxygen, and water vapour. 

  • It gives us air for breathing, protects the earth from the harmful rays of sun, and also maintains its temperature. In simple words, the atmosphere is the component that helps life to sustain on the planet.

7. Define air pressure.

Ans: The atmosphere exerts pressure on the earth’s surface. This weight of air on the surface of the earth is defined as air pressure.

8. Tell the name of three types of rainfalls.

Ans: The three different types of rainfall are as follows:

  • Convectional rainfall

  • Orographic rainfall

  • Cyclonic rainfall

9. What do you mean by weather? 

Ans: The state or condition of the atmosphere at a particular place at a particular time is called weather. It changes on an hourly and daily basis.

10. Which gas is responsible for greenhouse effect?

Ans: Carbon dioxide is the gas responsible for the occurrence of the greenhouse effect.

Short Answer Questions:                                                                     3 Marks

11. Why do wet clothes take a longer time to dry on a humid day?

Ans: Wet clothes dry when the water on them escapes into the atmosphere. On humid days, the water vapour content in the air is already quite high. This affects the rate of evaporation which means that only less quantity water is able to escape in the atmosphere from the wet clothes. As a result, the clothes take a longer time to dry on a humid day.

12. From the equator to poles the amount of insolation decreases, why?

Ans: The amount of insolation decreases from the equator to the poles because of the sun rays. This can be defined as follows:

  • The rays of the sun cover a shorter distance while travelling to the equator as the equator is comparatively closer to the sun. These rays are also vertical. Consequently, the insolation is higher at the equator. 

  • Simultaneously if moved towards the poles, the rays become more angled. These rays also have to travel a longer distance to reach the poles as the poles are located comparatively far from the sun.  As a result, the heat in the process. 

Thus, the amount of insolation received reduces from the equator towards the poles.

13. What are the main elements that make the atmosphere?

Ans: The main elements that make up the atmosphere are as follows:

  • Nitrogen is the most abundant gas which makes up about $78$% of the atmosphere. 

  • The next major element is oxygen which consists of $21$% of the total mass of air present in the atmosphere.

  • Argon and carbon dioxide make up $0.93$% and $0.03$% respectively

  • Apart from these, other elements helium, ozone, hydrogen, minute dust particles are found in minor quantities. 

(Image Will Be Updated Soon)

Figure 4.1: Main elements that make up the atmosphere

14. How do the bacteria help plants in getting nitrogen from the air?

Ans: For plants, nitrogen is a very essential element to survive. But plants cannot take nitrogen directly from the atmosphere. This is when bacteria play an important role in delivering nitrogen from the atmosphere to plants. They intake the atmospheric nitrogen, converts it into a usable form that is suitable for plants. In this way, plants get nitrogen due to the functions of the bacteria.

15. Why do astronauts wear special suits whenever they participate in interstellar travel?

Ans: When they go for interstellar travel there isn’t any kind of atmosphere or atmospheric pressure present there. In such a situation, the normal human bodies of astronauts would exercise counter pressure. This would result in the bursting of their blood vessels and consequent bleeding. Hence, to resist that pressure and avoid such disastrous circumstances, astronauts wear special suits whenever they participate in interstellar travel.

Long Answer Questions:                                                                             5 Marks

16. Write a short note on the pressure distribution present in the atmosphere.

Ans: Air pressure is applied on the surface of the earth by the weight of air. This air pressure is not even and varies from place to place. The distribution of air pressure can be explained as follows:

  • The atmospheric pressure falls rapidly with the growing height in the atmosphere. At sea level, the air pressure is highest whereas it decreases with the increase in height. 

  • The temperature of the air plays a crucial role in determining the pressure of the air at a particular place. The hotter the air, the less pressure it exerts. Hence, places with higher temperatures rise the temperature of the air and it rises upward. This helps to create a low-pressure area. Similarly, places with lower temperatures feel higher air pressure.

17. Define wind and mention different kinds of winds.

Ans: The movement of the air from high-pressure areas to low-pressure areas is defined as wind. 

The wind is divided into three major kinds:

  • Permanent wind: These are winds which blow the whole year in the same direction. Westerlies, easterlies and trade winds are permanent winds.

  • Seasonal winds: Winds that change their directions in different seasons are called seasonal winds. For example – Monsoon.

  • Local Winds: Winds blowing in a certain area for a shorter period are called local winds. For example – Loo.

18. Explain the different kinds of layers of the atmosphere. 

Ans: Atmosphere is divided into the following five parts: 

  • Troposphere: This is the first layer of the atmosphere. The air we breathe as well as other gases are present in the troposphere. The troposphere extends up to an average height of about $13$km. Every phenomenon related to weather takes place in this layer.

  • Stratosphere: This comes after the troposphere. The stratosphere has its existence up to a height of about $50$km. Aeroplanes fly in the stratosphere as it is almost devoid of clouds and weather phenomena. This layer also contains ozone gas which protects the earth from fatal sun rays. 

  • Mesosphere: Mesosphere extends at a height of $80$ km and it starts where the stratosphere ends. The meteorites that come from space burn up here after entering the atmosphere.

  • Thermosphere: The temperature increases at a faster rate with a rise in height in this part of the atmosphere. As the ionosphere is present in this layer, it aids in radio transmission. It extends at altitudes between $90{\text{ - }}400$ km.

  • Exosphere: It is the atmosphere's last and uppermost layer. It is filled with air. Hydrogen and helium are common here.

(Image Will Be Updated Soon)

Figure 4.2: Layers of the atmosphere

19. Why is the temperature of the cities higher than that of villages?

Ans: Temperature of the cities higher than that of villages because of the following reasons:

  • Villages are the natural habitat of the people. Cities are the extended and modern version of the villages with a higher population. Hence, cities are very crowded with a larger rate of pollution. This pollution is caused due to gases emitted by vehicles and factories. These gases help in the rising of the temperature of the cities. 

  • The asphalt of roads, buildings’ concrete metals also soak the heat in the day and release it during the night, increasing the temperature of the cities as compared to the villages.

  • Also, the tall buildings present in the cities confines the hot and warm air and thus increase the temperature.

20. What is rainfall? What happens when excess rainfall takes place?

Ans: Rainfall can be defined as follows:

  • Precipitation that falls on the surface of the earth in liquid form is termed rain. 

  • It occurs due to the condensed gases which rise above the earth due to the high pressure of the wind and fall in the form of liquid droplets on the earth surface. 

  • The rainfall on the earth takes place due to gravity. 

  • Rainfall is also the main source of groundwater.

  • When excess rainfall takes place, it results in the occurrence of floods.

Significance of CBSE Class 7 Social Science Chapter 4 Our Environment Air Important Questions

The complete preparation of CBSE Class 7 Social Science Chapter 4 Our Environment Air will need the proper study material and the NCERT exercise solutions. Apart from these notes and exercise solutions, students will need an assessment platform to check their preparation level. When the chapter is fully prepared, this assessment platform will help students recognise the gaps in the preparations. This is where the important questions framed by the experts will be very handy.

Benefits of CBSE Class 7 Social Science Chapter 4 Our Environment Air Important Questions

  • The questions and answers have been framed to form a single file for convenience. You can access it online or can download it for more convenience.

  • Resolve doubts by using the solutions on your own.

  • Follow the answering formats to develop similar skills and score more in the exam.

Download CBSE Class 7 Social Science Chapter 4 Our Environment Air Important Questions PDF

Get the questions and answers and practise solving them to become better at answering such questions. Broaden your preparation level by preparing these questions and score more. Learn how to answer such questions with proper format and stay ahead of the competition.


Conclusion 

Vedantu's provision of important questions for CBSE Class 7 Science Our Environment Chapter 4 - "Air" serves as an invaluable tool for students. These questions are thoughtfully designed to enhance the learning experience and exam preparation. They encourage critical thinking and a deeper understanding of the vital concepts related to our planet's atmosphere. By practising these important questions, students can assess their knowledge, identify areas that need further exploration, and build confidence in their problem-solving skills. Vedantu's commitment to quality education is evident, as these questions empower students to excel in their science studies, fostering a heightened awareness of the critical role air plays in our environment and its significance to our lives.

FAQs on Important Questions for CBSE Class 7 Science Our Environment Chapter 4 - Air

1. Why should I solve these important questions?

These questions have been formulated by following the latest CBSE syllabus to cover the utilisation of all the concepts taught in this chapter.

2. How can I judge my preparation level for Class 7 Social Science Chapter 4?

Once the chapter is prepared, students can solve these questions at home and compare their answers to the solutions given. They can find out which part of this chapter needs more attention.

3. How can I develop my concepts for Class 7 Social Science Chapter 4 Air?

The questions and answers formulated for these questions will also work for the development of the conceptual foundation of the students. They will show how to use the concepts well to frame precise answers.

4. Where can I find the answers to these important questions?

The questions come with respective solutions to follow. You can refer to these answers and prepare these questions accordingly.

5. Will solving these questions benefit me?

Practising answering social science questions will help you understand the concepts and will make you more time efficient. You can use the exam time properly and score more.