Storms and Cyclones
Q42. Write a note on wind flow pattern.
Regions close to the equator get maximum heat from the Sun. The air in these
regions gets warm. The warm air rises, and the cooler air from the regions in
the 0–30 degrees latitude belt on either side of the equator moves in. These
winds blow from the north and the south towards the equator. At the poles, the
air is colder than that at latitudes about 60 degrees. The warm air at these
latitudes rises up and the cold wind from the polar regions rushes in, to take
its place. In this way, wind circulation is set up from the poles to the warmer
Q43. How a thunderstorm becomes a cyclone?
Before cloud formation, water takes up heat from the atmosphere to change into
vapour. When water vapour changes back to liquid form as raindrops, this heat
is released to the atmosphere. The heat released to the atmosphere warms the
air around. The air tends to rise and causes a drop in pressure. More air rushes
to the centre of the storm. This cycle is repeated. The chain of events ends
with the formation of a very low-pressure system with very high-speed winds
revolving around it. It is this weather condition that we call a cyclone.
Q44. List some action on the part of people in case of cyclone.
on the part of people in case of cyclone
We should not ignore the warnings issued by
the meteorological department through TV, radio, or newspapers.
We should — make necessary arrangements to
shift the essential household goods, domestic animals and vehicles, etc. to
safer places; avoid driving on roads through standing water, as floods may have
damaged the roads; and keep ready the phone numbers of all emergency services
like police, fire brigade, and medical centres.
Q45. What precautions would you take, if you are staying in a
cyclone hit area?
Some precautions, if we are staying in a cyclone hit area —
Do not drink water that could be
contaminated. Always store drinking water for emergencies.
Do not touch wet switches and fallen power
Do not go out just for the sake of fun.
Do not pressurise the rescue force by
making undue demands.
Cooperate and help your neighbours and
Q46. What precautions should we take if a storm is accompanied
If a storm is accompanied by lightning, we must take the following precautions:
Do not take shelter under an isolated tree.
If you are in a forest take shelter under a small tree. Do not lie on the
Do not take shelter under an umbrella with
a metallic end.
Do not sit near a window. Open garages,
storage sheds, metal sheds are not safe places to take shelter.
A car or a bus is a safe place to take
If you are in water, get out and go inside
Q47. Write an experiment to show that air exerts pressure.
Take a tin can with a lid. Fill it approximately half with water. Heat the can
on a candle flame till the water boils. Let the water boil for a few minutes.
Blow out the candle. Immediately put the lid tightly on the can. Put the can
carefully in a shallow metallic vessel or a washbasin. Pour fresh water over
the can. As water is poured over the can, some steam in the can
condenses into water, reducing the amount of air inside. The pressure of air
inside the can decreases than the pressure exerted by the air from outside the
can. As a result the can gets compressed.
Image from NCERT