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Class 7 Science, Chapter 8 - Winds, Storms and Cyclones:, Question1. Fill the missing word in the blank spaces in the following statements:, (a) Wind is——————air., Answer (a): moving., , (b) Winds are generated due to——————heating on the earth., Answer (b): uneven., (c) Near the earth’s surface __________air rises up whereas ___________ air comes down., Answer (c): warm, cold., (d) Air moves from a region of ——— pressure to a region of——— pressure., , Answer (d): high, low., Question2. Suggest two methods to find out wind direction at a given place., Solution (2):, Two methods are:, (i) Tie a lightweight strand or tassel to an object & hang it freely. As the wind blows, the strand or, tassel will also move right along with it. The direction of the wind will be the direction in which, the tassel points., , (ii) Take some soapy water and a straw. With the help of a straw blow some bubbles in the air,, the direction in which the bubble will move also will be the direction of the wind., Question3. State two experiences that made you think that air exerts pressure (other than those, given in the text)., , Solution (3):, Two experiences are:
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(i) Fill a glass (one-third of its volume) with water; cover the entire mouth with a playing card., Hold the playing card in the place and turn it upside down. Now as you will remove the hand,, the card will remain in the same position for some time and water will not fall. This shows that air, is exerting pressure on the card., , (ii) The door often slam whenever we open the window shows that air exerts pressure., Question4. You want to buy a house. Would you like to buy a house having windows but no, ventilators? Explain your answer., , Solution (4):, No, because ventilators are generally at a higher height than the windows. Warm air being, lighter than cold air rises up. With the help of ventilators, the warm air can easily go out of the, room and will maintain proper air circulation., Question5. Explain why holes are made in hanging banners and hoardings., Solution (5):, Wind exerts pressure and can displace banners and hoardings. But with the help of holes, air, can easily pass through it. This reduces the air pressure on the banners and hoarding., Question6. How will you help your neighbours in case cyclone approaches your village/town?, Solution (6):, As the warning will be issued, we should communicate the warning to the neighbours. We can, also help them in shifting to shelter homes. If required, we can also provide medical facilities &, clean water to them., Question7. What planning is required in advance to deal with the situation created by a, cyclone?, Solution (7):, To deal with the situation created by a cyclone, there should be a proper system for prediction of, the time & intensity of the cyclone accurately. In case of any incoming cyclone, a warning should, be sent to the masses through mobiles, radios and televisions. Proper arrangements should be, made for shifting of people to these shelter houses or safer areas. An adequate amount of clean, water, food and medicines should be stocked for future use.
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Question8. Which one of the following place is unlikely to be affected by a cyclone., (i) Chennai, (ii) Mangaluru (Mangalore), (iii) Amritsar, (iv) Puri, Solution (8):, The correct option is (iii) Amritsar., Question9. 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., Solution (9):, Only option (i) is correct.
