Winds Storms and Cyclones - Solutions
CBSE Class–VII Science
NCERT Solutions
CHAPTER-08
WINDS, STORMS AND CYCLONES
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 cold 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 given place.
Answer: Two methods to find out wind direction at a given place:
(i)Take some sand and release it from height. The direction in which the sand starts flowing is the direction of the wind.
(ii) Take an air balloon and releases it in the open space. The balloon will starts moving in one direction which will give you idea about the direction of the wind at that place.
Question 3. State two experiences that made you think that air exerts pressure( other than given in the text).
Answer: (i) When we fill air in a balloon it inflates due to pressure exerted by air. Also when it is overfilled with air it bursts due to excess air pressure.
(ii) When we hang a banner in a place of moving fast air, it tears due to the pressure exerted by the air.
Question 4. You want to buy a house. Would you like to buy a house having windows but not ventilators? Explain answer.
Answer: No, I would not like to buy a house having windows but no ventilators because Ventilators are important for the circulation of air. Warm air is lighter which rises up and exit from the ventilators. Cool air is heavier and thus move in through window making the room comfortable for living. .
Question 5. Explain why holes are made in hanging banners and hoardings.
Answer: Holes are made in hanging banners and hoardings in order to tackle the air pressure. The air get passed through these holes made on the hoardings or banners and thus reduces the pressure of air on them. Therefore, the hoardings do not get blown away or torn due to air pressure.
Question 6. How will you help your neighbors in case cyclone approaches your village/town?
Answer: I will help by following ways:
(i) By warning everyone about the coming danger.
(ii) Searching for shelter.
(iii) Keeping storage of water and food.
(iv) Setting up first facility.
Question 7. What planning is required in advance to deal with the situation created by a cyclone?
Answer:(i) Setting up cyclone warning system.
(ii) Setting up cyclone shelter.
(iii) Setting up food and water storage.
(iv) Setting up first aid facility.
Question 8. Which one of the following places 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 highpressure system with very highspeed 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.
