NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones

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

(a) Wind is__________air.

Answer: moving

(b) Winds are generated due to__________heating on the earth.

Answer: uneven

(c) Near the earth’s surface __________air rises up where as ___________ air comes down.

Answer: hot, cool

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

Answer: high, low

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

Answer:

1. Take some dry leaves or bits of paper. Now allow then to fall. While falling down these move with the flow of air. This suggest the direction of wind.
2. Riding a bicycle is a good method to determine wind direction. If one face difficulty in pedaling the bicycle, the person is moving on bicycle in opposite direction to wind. If bicycle can be pedaled easily then the person is moving on bicycle in direction of wind.

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

Answer:

• When you blow a balloon with air, balloon gets inflated. If excess of air if filled in balloon, it bursts. This shows that air exerts pressure .
• Blowing air moves curtains in the house, showing air exerts pressure.
• Air filled tires of a vehicle supports heavy body of vehicle due to air pressure.

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

Answer: If house has no ventilation, then warm air from the house, cannot move out of the house. Warm air is lighter, therefore it rises up and move out of the house through ventilation, also, cool air from outside moves inside the house. Thus, it will be a bad choice to buy a house without having ventilation.

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

Answer: If observed carefully, it can be noticed that, banners and hoardings have small holes created all over it. This is done, so that air could easily pass through these holes, thereby exerting less pressure on the banner or hoarding, thus, preventing a banner or hoarding from tearing due to pressure of air.

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

Answer: In case of cyclone, neighbours can be helped in following ways-

• Make all aware about cyclone predictions
• Find safe shelter for humans as well as animals
• Make First aid facility available in case of injury
• Carry required amount of food and clean water

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

Answer:

• Warning systems should be made available
• Cyclone shelters should be build
• Arrangement of moving people and animals to cyclone shelter should be made.
• Arrangement of food, water and first aid
• Awareness about safety measures should be spread

8. Which one of the following place is unlikely to be affected by a cyclone.

(i) Chennai (ii) Mangaluru (Mangalore) (iii) Amritsar (iv) Puri

Answer: Amritsar

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 a very high-pressure system with very

high-speed winds revolving around it.

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

Answer: In winter the winds flow from the land to the ocean.

Check other lessons NCERT Solutions for Class 7

Download free NCERT textbook class 7 Science – Chapter 8 Winds, Storms and Cyclones