(Class IX)

Question 1:
Choose the correct answer from the four alternatives given below.
(i) Which one of the following places receives the highest rainfall in the world?
(a) Silchar
(b) Cherrapunji
(c) Mawsynram
(d) Guwahati
Answer:
(c) Mawsynram

(ii) The wind blowing in the northern plains in summers is known as:
(a) Kaal Baisakhi
(b) Trade Winds
(c) Loo
(d) None of the above
Answer:
(c) Loo

(iii) Which one of the following causes rainfall during winters in north-western
part of India?
(a) Cyclonic depression
(b) Western disturbances
(c) Retreating monsoon
(d) Southwest monsoon
Answer:
(b) Western disturbances

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 (Class IX)
(iv) Monsoon arrives in India approximately in:
(a) Early May
(b) Early June
(c) Early July
(d) Early August
Answer:
(b) Early June

(v) Which one of the following characterises the cold weather season in India?
(a) Warm days and warm nights
(b) Warm days and cold nights
(c) Cool days and cold nights
(d) Cold days and warm nights
Answer:
(c) Cool days and cold nights

Question 2:
Answer the following questions briefly.
(i) What are the controls affecting the climate of India?
(ii) Why does India have a monsoon type of climate?
(iii) Which part of India does experience the highest diurnal range of temperature
and why?
(iv) Which winds account for rainfall along the Malabar coast?
(v) What are Jet streams and how do they affect the climate of India?
(vi) Define monsoons. What do you understand by “break” in monsoon?
(vii) Why is the monsoon considered a unifying bond?

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Answer 2:
(i) Latitude, Altitude and Pressure and Winds are the main factors which affect
the climate of India.
(ii) India comes in the Inter Tropical Convergence Zone (ITCZ). This fact; in
association with various other factors, like the El Nino, Jet Stream and Coriolois
Force are the reasons for monsoon type of climate in India.
(iii) Northwestern part of India experiences the highest diurnal range of
temperature. This happens because of the presence of the Thar Desert and also
because this region does not have the moderating influence of the ocean.
(iv) Monsoon winds
(v) Fast flowing and narrow air currents are called jet streams. The streams flow
at high altitudes (about 12,000 feet) in the troposphere. The westerly jet streams
are responsible for western cyclonic disturbances in the north and north-western
parts of India. The subtropical westerly jet stream moves north of the Himalayas
with the apparent movement of the sun. The tropical jet stream (an easterly jet
stream) blows over the Indian Peninsula; approximately over 14° north during the
summer months.
(vi) The seasonal reversal in wind direction during a year is called monsoon.
Monsoon tends to have ‘breaks’ in rainfall; which means that there are wet and
dry spells in between. The monsoon rains take place only for a few days at a time
and then come the rainless intervals.
(vii) Although there are wide variations in weather patterns across India, the
monsoon brings some unifying influences on India. The Indian landscape, its
flora and fauna, etc. are highly influenced by the monsoon. The entire agricultural
calendar in India is governed by the monsoon. Most of the festivals in India are
related to agricultural cycle. These festivals may be known by different names in
different parts of the country, but their celebration is decided by the monsoon. It
is also said that the river valleys which carry the rainwater also unite as a single
river valley unit. Due to these reasons, monsoon is often a great unifying factor
in India.

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Question 3:
Why does the rainfall decrease from the east to the west in Northern India?
Answer 3:
The Bay of Bengal branch of the monsoon winds moves towards northeast and
return westwards covering the northern plains. While they move towards west,
their moisture contains tends to reduce with subsequent rains. Hence the rainfall
decreases from east to west in northern India.

Question 4:
Give reasons as to why.
(i) Seasonal reversal of wind direction takes place over the Indian subcontinent?
(ii) The bulk of rainfall in India is concentrated over a few months.
(iii) The Tamil Nadu coast receives winter rainfall.
(iv) The delta region of the eastern coast is frequently struck by cyclones.
(v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are
drought-prone.
Answer 4:
(i) Seasonal reversal of wind direction over the Indian subcontinent takes place
due to pressure differential. El Nino has major role to play in the seasonal reversal
of wind direction over the Indian subcontinent.
(ii) The monsoon begins from the first week of June and advances quite rapidly
to cover almost the whole country by mid-July. Hence, the bulk of rainfall in
India is concentrated over the months of a few months; mainly June to August.
(iii) The Tami Nadu coast receives winter rainfall because of movement of low-
pressure conditions to the Bay of Bengal.
(iv) The Bay of Bengal is the centre of various pressure changes and hence there
is always a chance of development of cyclone. Due to this, the delta region of the
eastern coast is frequently struck by cyclones.
(v) The parts fall in the rain shadow area of the Aravalli. Hence, they are drought
prone.

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Question 5:
Describe the regional variations in the climatic conditions of India with the help
of suitable examples.
Answer 5:
Indian Peninsular shows wide variations in climatic conditions across various
regions. For example; during winter season, the temperature goes into negative
in the Himalayan region. In the northwestern India, temperatures can range
between zero degree to 15°C during winter. During the same season, the
temperature in Chennai remains a comfortable 25°C. The same variation can be
seen in summer as well, while the temperature in Rajasthan can hover around
47°C, it is a comfortable 30°C in Chennai.

Question 6:
Discuss the mechanism of monsoons.
Answer 6:
The low-pressure condition over the northern plains intensifies by the beginning
of June. It attracts the trade winds from the southern hemisphere. These south-
east trade winds cross the equator and blow in a south-westerly direction to enter
the Indian peninsula as the south-west monsoon. These winds bring abundant
moisture to the subcontinent.

Question 7:
Give an account of weather conditions and characteristics of the cold season.
Answer 7:
The temperature ranges between 10°-15°C in the northern plains. The weather is
usually marked by clear sky, low temperatures and low humidity and feeble
variable winds. The inflow of the cyclonic disturbances from the west and the
northwest is a characteristic feature of the cold weather over the northern plains.
These low-pressure systems originate over the Mediterranean Sea and Western
Asia and move into India. They cause winter rains over the plains and snowfall
in the mountains.

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Question 8:
Give the characteristics and effects of the monsoon rainfall in India.
Answer 8:
Monsoon tends to have ‘breaks’ in rainfall; which means that there are wet and
dry spells in between. The monsoon is famous for its uncertainties. It may cause
heavy floods in one part of the country, and may be responsible for droughts in
other part. Because of its uncertain behaviour, it sometimes disturbs the farming
schedule in India. This affects millions of farmers all over the country.