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Chapter 8
Winds, Storms and Cyclones
1. What is wind?
Ans. Moving air is called wind.
2. How air moves?
Ans. Air moves from the region where the air pressure is high to the region where
the pressure is low.
3. What brings rain on earth?
Ans. Winds carrying water vapor bring rains.
4. What happens to air on heating and cooling?
Ans. Air expands on heating and contracts on cooling.
5. Why warm is lighter than cold air?
Ans. Because warm air has high temperature (due to heating) and thus it expands
and occupies more space. When the same thing occupies more space, it becomes
lighter. The warm air is therefore, lighter than cold air.
6. Name the instrument used for measuring speed of wind.
Ans. Anemometer
7. What is a thunderstorm?
Ans. The swift movement of the falling water droplets along with the rising air
creates lightening and sound. It is this event that we call a thunderstorm.
8. What precautions we should take in case of thunderstorm?
Ans.
i)
ii)
iii)
Do not sit near a window. Open garages, metal sheds are not safe places to
take shelter.
A car or a bus is a safe place to take shelter.
If you are in water, get out and go inside a building.
9. Briefly explain the structure of a cyclone.
Ans. The center of a cyclone is a calm area. It is called the eye of the cyclone. A
large cyclone is a violently rotating mass of air in the atmosphere, 10 to 15 m Km
high. The diameter of the eye varies from 10 to 30 km. It is region free of clouds
and has light winds. The formation of a cyclone is a very complex process.
10. What factors contribute to the formation of a cyclone?
Ans. Factors like wind speed, wind direction, temperature and humidity contribute
to the formation of the cyclone.
11. What are the different names of cyclone?
Ans. It is called a ‘hurricane’ in the American continent and ‘tornadoes’ in India.
In the Philippines and Japan, it is called as ‘typhoon’.
12. Mention some safety measures for cyclones.
Ans.
i)
ii)
iii)
A cyclone forecast and warning service.
Rapid communication of warnings to the government agencies, the ports,
fisherman, ships and to the general public.
Construction of cyclone shelters in the cyclone prone areas.
13. Mention some precautions for people staying in a cyclone hit area.
Ans.
i)
ii)
iii)
iv)
v)
Do not drink water that should be contaminated. Always store drinking
water for emergencies.
Do not touch wet switches and fallen power lines.
Do not go out just for the sake of fun.
Do not pressurize the rescue force by making undue demands.
Cooperate and help yours neighbors and friends.