NCERT Solution class 7 Science Chapter-8

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NCERT Solution class 7 Science Chapter-8

Chapter – 8 Winds, Storms and Cyclones

Chapter Exercise

Page no. –  (92)

 

Q.1– Fill the missing word in the blank spaces in the following statements:

  1. Wind is ­­____ air.
  2. Winds are generated due to ____ heating on the earth.
  3. Near the earth’s surface ____ air rises up whereas ____ air comes down.
  4. Air moves from a region of ____ pressure to a region of pressure.

Ans.1–

  1. Wind is ­­__moving__ air.
  2. Winds are generated due to __uneven__ heating on the earth.
  3. Near the earth’s surface __worm__ air rises up whereas __cooler__ air comes down.
  4. Air moves from a region of __high__ pressure to a region of __low__

 

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

Ans.2– The two method to find out wind direction are:-

  1. First go in open, Take a leave and drop and sea wind direction.
  2. Take handchief in your hand and sea wind direction.

 

Q.3– State two experience that made you think that air exerts pressure (other than those given in the text).

Ans.3– The two experience are following:-

  1. Compressed air is used for braking system in trains.
  2. Blowing air in a balloon make it expand.

 

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

Ans.4– No, Because smoke from kitchen and warm air being lightly rise up and if there no outlet or ventilators, it is very hard to escape for warm air and will heat up whole house. So, these is very difficult to leave there.

 

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

Ans.5– The air can travel and pass everywhere very easily and Holes in the banners and hoardings helps air to pass through it. Hence, banner can withstand the pressure of the air and remains intact.

 

Q.6– How will you help your neighbours in case cyclone approaches your village/ town?

Ans.6– In the Case of cyclone, I should do these steps for helps our neighbor:-

  1. First of all I would warn my neighbors about the cyclone.
  2. I will arrange for everyone’s food and drink.
  • I will support all the soldiers of the rescue team.
  1. Assist in taking the victims to a safe place in case of disaster.
  2. I would abstain from going to the place where the cyclone is.

 

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

Ans.7– The planning required in advance to face cyclone disaster are following:-

  1. Store enough food and clean water at home.
  2. Do not touch fallen power lines.
  • Cooperate with rescue team.
  1. Helps our neighbor.
  2. Keep an first aid kit at home.
  3. Avoid to going in cyclone infested area and city.

 

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

  1. Chennai
  2. Mangaluru (Mangalore)
  3. Amritsar
  4. Puri

Ans.8– c) Amritsar.

 

Page no. – (93)

 

Q.9– Which of the statements given below is correct?

  1. In winter the winds flow from the land to the ocean.
  2. In summer the winds flow from the land towards the ocean.
  • A cyclone is formed by a very high-pressure system with very high-speed winds revolving around it.
  1. The coastline of India is not vulnerable to cyclones.

Ans.9– i. In winter the winds flow from the land to the ocean.