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

Exercises

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

(a) Wind is __________ air.

(b) Winds are generated due to __________ heating on the earth.

(c) Near the earth’s surface __________ air rises up whereas ___________ air comes down.

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

Answer:- (a) Wind is moving air.

(b) Winds are generated due to uneven heating on the earth.

(c) Near the earth’s surface warm air rises up whereas cooler air comes down.

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

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

Answer:- (i) Take a piece of paper and fold it in half. Allow it to float away from your grasp. It will flow in the same direction as the wind.

(ii) You can also utilise a wind-pane, which allows us to determine the exact direction of the wind.

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

Answer:-  (i)  Balloons and balls can only be used when they are fully inflated. Excessive air pressure causes a balloon to rupture when it is overfilled with air.

(ii) To stop trains, compressed air is employed in the brake system.

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

Answer:- No, living in a house without ventilators is neither safe nor healthful. In such a house, there is no air circulation. As a result, it is devoid of fresh air. Warm air rises and escapes through ventilators, while fresh air enters through windows.

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

Answer:- Air exerts pressure  on banners and hoarding as a result of this pressure it flutter and torn when wind is blowing fast. Holes are made in banners and hoardings so that wind passes through these holes and they do not become loose and fall down.

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

Answer:- (i) I’ll inform them about the cyclone forecast and warning system.

(ii) Prompt notification of the warning to all relevant government agencies and locations.

iii) In cyclone-prone locations, the construction of cyclone shelters.

(iv) Assisting them in relocating critical commodities, domestic animals, and other valuables to safer locations.

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

Answer:- It is critical to follow the following guidelines when dealing with a cyclone:

(i) paying close attention to warnings broadcast on television and radio.

(ii) relocating to a safer location.

iii) Having an emergency kit on hand.

(iv) Keep food in watertight bags.

(v) not going into the water.

(vi) making a list of all emergency phone numbers.

Question:- 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:- (iii) Amritsar            

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