Class 9 Geography | Climate | NCERT Solutions | Important Question Answer | Term 2 Social science

Class 9 Geography chapter 4 Climate Question Answer/ NCERT solutions 

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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) Mawsynram 

(c) Cherrapunji

(d) Guwahati

(ii) The wind blowing in the northern plains in summers is known as:

(a) Kaal Baisakhi 

(b) Loo 

(c) Trade Winds

(d) None of the above

(iii) Which one of the following causes rainfall during winters in north-western part of India.

(a) Cyclonic depression 

(b) Retreating monsoon

(c) Western disturbances

(d) Southwest monsoon

 

(iv) Monsoon arrives in India approximately in:

(a) Early May 

(b) Early July 

(c) Early June

(d) Early August

(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

2. Answer the following questions briefly.

(i) What are the controls affecting the climate of India?

Answer: 

There are six major controls of the climate of any place. They are: latitude, altitude, pressure and wind system, distance from the sea (continentality), ocean currents and relief features

(ii) Why does India have a monsoon type of climate?

Answer: 

India have a monsoon type of climate - as the word monsoon has derived from the Arabic word 'Mausim' meaning seasonal reversal of wind system.For the first time the sailors in Arabian sea noticed the change in wind system prevailing in India. The Monsoon type of climate Characterised by :-

i. Variations in temperature and rainfall pattern from place to place. 

ii.  Weather conditions changes from season to season. 

iii. The monsoon winds which comes from South-west region bring rain fall in all over India during the month June to September. 

iv. The summer monsoon when blow from sea to land carries moisture cause rainfall. 

v. The winter monsoon blow from the northern side of Indian subcontinent which doesn't contains moisture so, there is no rainfall or very less rainfall. 

(iii) Which part of India does experience the highest diurnal range of temperature and why?

Answer: 

In the Thar Desert the day temperature may rise to 50°C, and drop down to near 15°C the same night, due to lack of vegetation. 

(iv) Which winds account for rainfall along the Malabar coast?

Answer: 

South-West Monsoon Winds, are responsible for rainfall along the Malabar coast. 

(v) What are Jet streams and how do they affect the climate of India?

Answer: 

i. Jet stream are a narrow belt of high altitude 

westerly winds in the troposphere.

ii. Jet stream located over 27° and 30° latitude called subtropical westerly Jet stream. 

 iii. Their speed varies from about 110 km/h in summer to about 184 km/h in winter. 

iv. A number of separate jet streams have         been identified. Mid-latitude and the sub-     tropical  are two constant Jet stream. 

(vi) Define monsoons. What do you understand by “break” in monsoon?

Answer: 

The word monsoon has been derived from the Arabic word ‘mausim’ which literally means season. ‘Monsoon’ refers to the seasonal reversal in the wind direction during a year.

The break in the monsoon rainfall refers to the dry spells when the monsoon rain takes place
only for a few days at a time. These breaks are related to the movement of the monsoon trough. When the axis of the monsoon trough lies over the plains, then the rainfall is heavier there. When the trough moves towards the Himalayas, the plains are dry but there is heavy rainfall occur over the mountains.

(vii) Why is the monsoon considered a unifying bond?

Answer: 

 i. There is a great variation in temperature conditions in the subcontinent of India.

ii. The monsoons have a unifying influence as Precipitation that is caused affects the entire country.

iii. The monsoon winds bind the whole country by providing water for agriculture that's why Monsoon considered a unifying bond in subcontinent of India. 

 

3. Why does the rainfall decrease from the east to the west in Northern India?

Answer : 

 

The rainfall decrease from the east to the west in northern India because of the direction of the winds. It lose its moisture by the movement of the winds. 

4. Give reasons as to why.

(i) Seasonal reversal of wind direction takes place over the Indian subcontinent?

Answer :

    Seasonal reversal of wind detection takes place over the Indian subcontinent due to difference in wind pressure. 

El Nino also play a vital role for reversal of wind direction in India. 

(ii) The bulk of rainfall in India is concentrated over a few months.

Answer :

India receives rainfall due to South - West monsoon winds. The duration of monsoon winds is between 100 to 120 days. It enters to India from its southward side in the month of June and by the month of September it touches almost part of India. Hence the bulk of rainfall in India is concentrated over a few months. 

(iii) The Tamil Nadu coast receives winter rainfall.

Answer:

During winter north- east trade winds which moves from land to sea prevails most of part of India. This winds do not holds any moisture so there is dry season. However in Tamilnadu coast the winds blow from sea to land carrying moisture cause rainfall in Tamilnadu coast receives winter rainfall. 

(iv) The delta region of the eastern coast is frequently struck by cyclones. 

Answer:

The Delta region of the eastern coast is frequently struck by cyclone because of the depression originated over Bay of Bengal brought in by sub-tropical easterly jet stream. It causes widespread rainfall in the peninsula India.These cyclones are destructive in nature. It mostly affect Odisha, West Bengal and Andhrapradesh. 

(v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought-prone.

Answer:

Part of Rajasthan, Gujarat and the Leeward side of the Western Ghats are drought-prone because they fall in the rain shadow region of Aravali hills. The slope of mountain which facing the moisture winds (south-west) receives high rainfall and the Leeward (opposite) side of the Western ghat receives very less rainfall hence those are drought-prone. 

Q5. Describe the regional variations in the climatic conditions of India with the help of suitable examples.

Answer : 

There is regional variations in the climatic conditions due to difference in topography, temperature and rainfall,For example :-

i. In the summer season the temperature in some part of of Rajasthan reaches to 50° C, where as the temperature at Pahalgam in Kashmir is around 20°C.

ii. Similarly in winters night the temperature in Kashmir goes minuse 45°C,  at the same time Thiruvananthapuram in Kerala have a temperature of 20°C.

  In comparison to the interior of the country, the coastal and peninsula area experience very less seasonal contrasts. 

iii. There is also variation in perception pattern in India. In Himalayan region the  form precipitation is snowfall in the upper part. 

iv. Variation in amount from 400cm in Meghalaya to less than 10cm In Ladakh and Thar desert of Rajasthan. 

v. Most of the country receives rainfall in the month of June to September only Tamilnadu coast gets it in the month of October and November. 

Q6. Discuss the mechanism of monsoons.

Answer:

Following are the mechanism of monsoon

i. The differential heating and cooling of land water

ii. The shift of the position of inter Tropical Convergence Zone.

iii. The presence of the high-pressure area, east of  Madagascar.

iv. The Tibetan plateau gets Intensely heated.

v. The movement of the western jet stream to the north of the Himalayas and the Presence of the tropical easterly jet stream over the Indian peninsula during summer.

7. Give an account of weather conditions and characteristics of the cold season.

Answer :

The cold season in India start from mid of November and last till February.During this season the northeast trade winds prevail  over the subcontinent of India, they are dry as they blow from land to sea.This season is characterized by the following weather conditions :-

i. The temperature decreases from South to North.

ii. Days are warm and Dry and Nights are cold.

iii. Frosts are common in northern India and the Himalayan region experience snowfall.

iv. December and January are the coldest months in the northern part of the county.

v. The peninsula regions experience less impact of season change due to the moderating influence of  seas.

8. Give the characteristics and effects of the monsoon rainfall in India.

Answer :

The monsoon rainfall in India characterized by the following things -

i. The duration of the monsoon varies from 100 to 120 days from early June to mid- September.

ii.Around the time of its arrival, the normal rainfall increases suddenly and continues regularly for several days. This is called the ‘burst’ of the monsoon.

iii. They are distinguished from the pre-monsoon showers because of their increase in rainfall amount and regularity.

iv. The monsoon arrives at the southern tip of the Indian Peninsular generally by the first week of June.

v.The rainfall is unevenly distributed across the country.

Effects of the monsoon rainfall in India:

a)Agriculture in India largely depends on Indian monsoons for water. Late, Low or excessive rains have a negative impact on crops.

b)Due to uneven distribution of rainfall across the country, there are few places that are drought-prone and few are flood affected.

c )The monsoon provides India with a diverse climatic pattern. Hence, in spite of the presence of great regional variations, it has a unifying influence upon the country and its people.