Class seven science chapter 8 NCERT Solutions
Chapter 8: Winds, Storms and Cyclones
N C E R T Textbook Questions Solved
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) moving (b) uneven
(c) warm, cooler (d) high, low
2. Suggest two methods to find out wind direction at a given place.
Answer: (i) Take a piece of paper in your hand. Allow it to fall from your hand. It will flow in the direction in which wind is blowing.
(ii) You can also use a wind-pane which helps us to know the accurate wind direction.
3. State two experiences that made you think that air exerts pressure.
Answer: (i) Balloons and balls can be used only when they are inflated with air. When the balloon is overfilled with air it bursts due to excessive air pressure.
(ii) Compressed air is used in the brake system for stopping trains.
4. You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.
Answer: No because ventilators help to circulate air inside the house. The warm air of the house rises up and moves out through ventilators. Then cool comes inside the house through the ventilators and take place of warm air. So, ventilators help to maintain the fresh air inside the house.
5. Explain why holes are made in hanging banners and hoardings.
Answer: Air exerts pressure. When the speed of the wind is high, this pressure can tear the banners and hoarding. Holes in banners and hoardings helps the air to pass through them which reduce the pressure on banners and hoardings.
6. How will you help your neighbours in case cyclone approaches your village/town?
Answer: (i) I will make them aware of cyclone forecast and warning service.
(ii) Rapid communication of warning to the government agencies and all the important places.
(iii) I will help them to move into cyclone shelters in the cyclone-prone areas.
(iv) I will help them to shift their essential goods, pets, etc. to safer places.
7. What planning is required in advance to deal with the situation created by a cyclone?
Answer: To deal with cyclone, it is important to follow the following points:
1. We would keep listening to the warnings and all the emergency numbers.
2. We would help our neighbours to move to a safe place.
3. We would keep an emergency kit with us which includes important medicines and bandage.
4. We would use waterproof bags to store food.
8. Which one of the following places is unlikely to be affected by a cyclone?
(i) Chennai
(iii) Amritsar
(ii) Mangalore
(iv) Puri
Answer: (iv) 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: (i) In winter the winds flow from the land to the ocean.
Answer: (i) Balloons and balls can be used only when they are inflated with air. When the balloon is overfilled with air it bursts due to excessive air pressure.
(ii) Compressed air is used in the brake system for stopping trains.
4. You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.
Answer: No because ventilators help to circulate air inside the house. The warm air of the house rises up and moves out through ventilators. Then cool comes inside the house through the ventilators and take place of warm air. So, ventilators help to maintain the fresh air inside the house.
5. Explain why holes are made in hanging banners and hoardings.
Answer: Air exerts pressure. When the speed of the wind is high, this pressure can tear the banners and hoarding. Holes in banners and hoardings helps the air to pass through them which reduce the pressure on banners and hoardings.
6. How will you help your neighbours in case cyclone approaches your village/town?
Answer: (i) I will make them aware of cyclone forecast and warning service.
(ii) Rapid communication of warning to the government agencies and all the important places.
(iii) I will help them to move into cyclone shelters in the cyclone-prone areas.
(iv) I will help them to shift their essential goods, pets, etc. to safer places.
7. What planning is required in advance to deal with the situation created by a cyclone?
Answer: To deal with cyclone, it is important to follow the following points:
1. We would keep listening to the warnings and all the emergency numbers.
2. We would help our neighbours to move to a safe place.
3. We would keep an emergency kit with us which includes important medicines and bandage.
4. We would use waterproof bags to store food.
8. Which one of the following places is unlikely to be affected by a cyclone?
(i) Chennai
(iii) Amritsar
(ii) Mangalore
(iv) Puri
Answer: (iv) 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: (i) In winter the winds flow from the land to the ocean.