1) Fill the missing word in the blank spaces in the following
statements:
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.
_________ air comes down.
(d) Air moves from a region _________of pressure to a region
_________of pressure.
_________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.
place.
ANSWER:-
(i) Take a piece of a paper in your hand.
Allow it to fall from your hand. It will flow in the
direction in which wind is blowing.
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 accurate
wind direction.
wind direction.
3) State two experiences that made you think that air exerts
pressure.
pressure.
ANSWER: –
(i) Balloons and balls can be used only when they are inflated
with air. When balloon is overfilled
with air it bursts due to excessive air pressure.
with air. When balloon is overfilled
with air it bursts due to excessive air pressure.
(ii) Compressed air is used in the brake system for stopping
trains.
trains.
4) You want to buy a house. Would you like to buy a house having
windows but no ventilators? Explain your answer.
windows but no ventilators? Explain your answer.
ANSWER:-No, a house which has no ventilators is not a safe or healthy
house to live in. The air circulation
is not there in such a house. So, it has no fresh air.
house to live in. The air circulation
is not there in such a house. So, it has no fresh air.
5).Explain why holes are made in hanging banners and hoardings.
ANSWER:-Air exerts pressure. Due to this pressure banners and hoarding
flutter and torn when wind is
blowing fast. Holes are made in banners and hoardings so that wind passes
through the holes and they do not become loose
and fall down.
flutter and torn when wind is
blowing fast. Holes are made in banners and hoardings so that wind passes
through the holes and they do not become loose
and fall down.
6) How will you help your neighbours in case cyclone approaches
your village/town?
your village/town?
ANSWER :- (i) I will make them aware of cyclone forecast and warning
service.
service.
(ii) Rapid communication of warning to the government
7) What planning is required in advance to deal with the
situation created by a cyclone?
situation created by a cyclone?
ANSWER:-To deal with cyclone, it is important to follow the following points:
(i) Carefully listening the warnings transmitted on T.V. and
radio.
radio.
(ii) Moving to the safer places.
(iii) Keeping an emergency kit ready.
(iv) Store food in waterproof bags.
8) Which one of the following places is unlikely to be affected by
cyclone?
cyclone?
(i) Chennai (ii) Mangalore
(iii) Amritsar (iv) Puri
ANSWER:-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.
very high-speed winds revolving around it.
(iv) The coastline of India is not vulnerable to cyclones.
ANSWER:-In winter the winds flow from the land to the ocean.