NCERT Solutions for Class 7 Science Chapter 8 - Winds, Storms And Cyclones (Not in the Current Syllabus)

1: Fill the missing word in the blank spaces in the following statements:

(a) Wind is ----------- air.

(b) Winds are generated due to --------------- heating.

(c) Near the earth’s surface ------------- air rises whereas ------- air comes down.

(d) Air moves from a region of ---------- pressure to a region of --- pressure.

Ans:(a) Wind is moving air.

(b) Winds are generated due to uneven heating.

(c) Near the earth’s surface hot air rises whereas cool air comes down.

(d) Air moves from a region of high pressure to a region of low pressure.

2: Suggest two methods to find out wind direction at a given place.

Ans: The two techniques are: 

(i) Looking at the direction shown on the wind vane and 

(ii) Observing the direction of the tree's leaves during a high wind.

3: State two experiences that made you think that air exerts pressure (other than given in the text).

Ans : 

(i) When you blow air into a balloon, it expands.

(ii) The movement of curtains on doors and windows can be aided by blowing air.

4: You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain answer.

Ans: No, living in a house with no ventilation is not a good idea. The cool air will enter through the windows, but the heated air will escape through the ventilation, which works as an exit door. As a result, ventilation is essential for the new home.

5: Explain why holes are made in hanging banners and hoardings.

Ans: Holes are drilled into the banners to allow air to pass through them. If there are no holes in the banner, the air pressure will be so high that it will shred the bear. As a result, the holes are drilled to aid in the reduction of air pressure on the banner.

6:How will you help your neighbors in case a cyclone approaches your village/town?

Ans: I'll assist in the following ways: 

(i) I'll alert everyone about the impending threat.

(ii) Looking for a place to stay.

(iii) Maintaining water and food stockpiles.

(iv) Establishing the first facility.

(v) By stocking up on first-aid supplies ahead of time.

7: What planning is required in advance to deal with the situation created by a cyclone?

Ans : 

(i) The installation of a cyclone warning system.

(ii) Constructing a cyclone shelter

(iii) Putting food and water reserves in place.

(iv) Establishing a first-aid station.

8:Which one of the following places is unlikely to be affected by a cyclone?

Ans: Amritsar is unlikely to get affected by a cyclone.

9: Which of the statements given below is correct?

(i) In winter the winds flow from the land to the ocean.

(ii) In summer the winds flow from the land towards the ocean.

(iii) A cyclone is formed by very high-speed winds revolving around it.

(iv) The coastline of India is not vulnerable to cyclones.

Ans: The statement (i) is correct that is, I Winds blow from the land to the sea in the winter.

NCERT Solutions for Class 7 Science Chapter 8 Free PDF Download

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Chapter 8 – Wind, Storm and Cyclone

Introduction

You must have heard a number of news regarding winds, storms, and cyclones at a particular place. You must be aware that high cyclones often affect agriculture, transport, communication, as well as the electricity supply at a place. Have you ever wondered what cyclones are? How are they formed? What is a storm? Where does it originate from? You will get answers to all your questions related to these topics in this chapter. Keep reading to know all the facts associated with wind, storm, and cyclones.

8.1 Air Exerts Pressure

Activity 8.1 deals with a little experiment that proves the fact that air exerts pressure. Have you ever rowed a boat? You must have noticed that when the wind is coming from behind, it helps you to row the boat faster and easier. This is because the air exerts pressure. This activity involves many such examples that will help you justify this statement. Go through all the topics carefully and in case of any doubts, reach out to Vedantu experts through our official website.

8.2 High-Speed Winds are Accompanied by Reduced Air Pressure

You must have studied in your previous classes that air moves from the high air pressure region to the low air pressure region. The greater the difference in pressure, the faster is its speed. This section deals with various experiments that will help you understand and prove the fact that increased wind speed is always accompanied by reduced air pressure. Make sure to perform all the experiments under the supervision of your teacher or parents.

8.3 Air Expands on Heating

Activity 8.5 and 8.6 must be performed under the supervision of adults. This section deals with the fact that air expands and occupies more space on heating, and as we know that when the same thing occupies more space then it becomes lighter in weight. Therefore, it proves that warm air is always lighter than cold air. Let us understand this with an example. 

Light a candle, and see if the flame goes up or down? It always goes up because the warm air is always lighter than the surrounding cold air. In some situations, when warm air rises at any place, the air pressure of that particular place is lowered. Therefore, cold air fills this place, thus setting up convection in air. The simple activities mentioned in this section will help you understand the concept in a better way.

8.4 Wind Currents are Generated Due to Uneven Heating on the Earth

(a) Uneven Heating Between the Equator and the Poles

As you know, regions located near to the equator get the maximum amount of heat from the sun. Warm air blows in these regions. As the warm air in these latitudes rises, the cold air from polar regions comes in and takes its place. In such a manner, wind circulation is set up from poles to warmer latitudes. Make sure to properly study the diagram mentioned in this section for a better understanding.

(b) Uneven Heating of Land and Water

During summers in the regions near the equator, the land always warms up faster, and hence the temperature of land is always higher than that of water bodies. As a result, the air over land gets heated and rises up which results in the flow of winds from the ocean towards the land. These are commonly known as monsoon winds. Therefore, in winters the direction is reversed as winds flow from land to ocean. These winds bring rain. Further in this section, you will learn in detail about the winds that cause rain. Read carefully to understand in detail. This section is extremely important for examination.

8.5 THunderstorm and Cyclones

Upward rising winds are a result of the rising temperature of any place. These winds often carry with them water droplets that freeze and then fall down. This swift movement of water droplets falling along with the rise of air creates lightning and sound in nature. Therefore, this event is broadly known as a thunderstorm. Similarly, in the next section, you will learn in detail about a cyclone, its formation, reason, and cause of formation of a cyclone.

How Does a Thunderstorm Become a Cyclone?

In this section, you shall read about the formation of a cyclone from a thunderstorm. This is usually the favourite of all science-loving students as it covers many facts related to the topic. Read in detail.

8.6 Destruction Caused by Cyclones

Cyclones can be very destructive. From causing the destruction of homes and living habitats of humans to being deadly for living beings, cyclones have caused a lot of destruction. It is also known by different names in different parts of the world, Hurricane and typhoon are two examples. In this section, you shall also learn about tornadoes. A tornado is a dark funnel-shaped cloud that extends from the sky to the ground. Small tornadoes can be formed within cyclones.

8.7 Effective Safety Measures

Safety and precautions from anything that is a threat to both human lives as well as nature are extremely important. This section educates you about some safety measures that you can follow as an individual to protect yourself and the people around you, from the destructive properties of a cyclone. It covers proper knowledge and interpretation of cyclone forecast and warning services.

Actions on Part of Common People:

1. Do not ignore the warnings in newspapers.

2. Take the necessary arrangements to shift your household in extreme conditions. 

3. Store drinking water for emergencies.

4. Do not touch wet switches.

5. Do not touch power lines fallen on the ground.

6. Avoid stepping out in bad weather.

7. Cooperate and help each other in times of need.

8.8 Advanced Technology has Helped

With the advancement in technology and weather forecast, the world is much prepared and safe from such natural calamities. All thanks to the satellites and radars that help the weather forecast department to issue a cyclone alert every 48 hours in advance when a storm or cyclone is expected. The message is then broadcasted to the public through media and necessary precautions and arrangements can be made to protect human lives. There are several national and international organizations that keep monitoring all the cyclone related issues and news.

Exercise Solutions: 9 Questions (2 short questions and 7 long questions).

Extended Learning – Activities and Projects: 6 questions.

Key Features of NCERT Solutions for Class 7 Science Chapter 8

Having adequate knowledge about cyclones and storms is extremely important for every individual. Along with being important from an examination point of view, sufficient knowledge of these concepts is also necessary for everyone. The CBSE class 7 Science chapter 8 solutions PDF by Vedantu experts not only help students with accurate NCERT answers but also provide in-depth knowledge of the chapter. Some notable key features of these solutions are:

1. These solutions prepared by the expert teachers provide you with easy and relevant study materials for your exam preparation. 

2. You can download the PDF at any time as per your convenience. 

3. It will help you gain a deeper knowledge and understanding of the concepts covered in this chapter. 

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