1. Choose the correct answer.
(i) Which one of the following places receives the highest rainfall in the world?
(a) Silchar
(b) Mawsynram
(c) Cherrapunji
(d) Guwahati
Answer: Mawsynram
(ii) The wind blowing in the northern plains in summer is known as:
(a) Kaal Baisakhi
(b) Loo
(c) Trade Winds
(d) None of the above
Answer: Loo
(iii) Which one of the following causes rainfall during winters in the northwestern part of India?
(a) Cyclonic depression
(b) Retreating monsoon
(c) Western disturbances
(d) Southwest monsoon
Answer: Western disturbances
(iv) Monsoon arrives in India approximately in:
(a) Early May
(b) Early July
(c) Early June
(d) Early August
Answer: 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: Warm days and cold nights.
2. Answer the following questions briefly.
(i) What are the factors affecting the climate of India?
Answer:
The major factors affecting the climate of India are:
- Latitude
- Altitude
- Pressure and Winds
(ii) Why does India have a monsoon type of climate?
Answer:
India has a monsoon type of climate because the direction of winds changes seasonally. The weather conditions also change from one season to another.
India has four main seasons:
- Cold Weather Season
- Hot Weather Season
- Advancing Monsoon
- Retreating Monsoon
The monsoon generally lasts from early June to mid-September.
(iii) Which part of India experiences the highest diurnal range of temperature and why?
Answer:
The northwestern part of India experiences the highest diurnal range of temperature. The presence of the Thar Desert is an important reason. This region is also away from the moderating influence of the ocean, so there is a large difference between day and night temperatures.
(iv) Which winds account for rainfall along the Malabar Coast?
Answer:
The Southwest 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:
Jet streams are narrow belts of high-altitude westerly winds in the troposphere. They blow at a height of about 12,000 metres or above.
They influence the weather conditions of India and play an important role during the monsoon season.
(vi) Define monsoons. What do you understand by “break” in monsoon?
Answer:
Monsoon refers to the seasonal reversal of wind direction during the year.
A break in monsoon occurs when the monsoon trough changes its position. When the trough moves towards the Himalayas, rainfall decreases in the plains and dry spells occur.
(vii) Why is the monsoon considered a unifying bond?
Answer:
The monsoon is considered a unifying bond because the life of people in India is closely connected with it.
- It provides water for agriculture.
- The agricultural calendar depends on monsoon rainfall.
- Plants, animals and the landscape are influenced by it.
- People across India eagerly wait for the monsoon.
Thus, the monsoon connects different parts of India through water, agriculture and people’s life.
3. Why does the rainfall decrease from the east to the west in Northern India?
Answer:
The monsoon winds move from east to west across Northern India. As they move westward, they gradually lose their moisture. Therefore, rainfall decreases from east to west.
4. Give reasons as to why.
(i) Seasonal reversal of wind direction takes place over the Indian subcontinent.
Answer:
The direction of winds changes with the change in seasons because of differences in pressure conditions over land and water. El Niño also influences the monsoon system.
(ii) The bulk of rainfall in India is concentrated over a few months.
Answer:
Most of India’s rainfall is received from the Southwest Monsoon winds. These winds rapidly cover most parts of the country by July. Therefore, a large part of the annual rainfall is received within a few months.
(iii) The Tamil Nadu coast receives winter rainfall.
Answer:
The Tamil Nadu coast receives winter rainfall mainly due to the North-East Monsoon winds.
(iv) The delta region of the eastern coast is frequently struck by cyclones.
Answer:
The Bay of Bengal experiences frequent changes in pressure. These conditions favour the formation of cyclones, which often affect the delta regions of the eastern coast.
(v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought-prone.
Answer:
These areas receive very little rainfall because they lie in rain-shadow regions. Hence, they are drought-prone.
5. Describe the regional variations in the climatic conditions of India with the help of suitable examples.
Answer:
India has considerable regional variations in temperature and climate.
| Region/Season | Example |
|---|---|
| Winter | Northern India becomes colder during December and January. |
| Northern Plains | Temperature generally ranges between 10°C and 15°C. |
| Chennai | Average temperature remains around 24°C–25°C during winter. |
| March | Deccan Plateau may record about 38°C. |
| April | Gujarat and Madhya Pradesh may have temperatures around 42°C. |
| May | Northwestern India commonly experiences temperatures around 45°C. |
| Peninsular India | Temperatures remain comparatively lower because of the moderating influence of the sea. |
Thus, temperature and climatic conditions vary considerably from one region of India to another.
6. Discuss the mechanisms of the monsoon.
Answer:
The main factors responsible for the mechanism of the Indian monsoon are:
- Differential heating of land and water creates low pressure over India and comparatively high pressure over the surrounding seas.
- The ITCZ shifts northwards over the Ganga Plain during summer.
- A high-pressure area near Madagascar influences the Indian monsoon.
- The Tibetan Plateau becomes intensely heated during summer and develops low pressure.
- The movement of jet streams also influences the monsoon.
These factors together help in the formation and movement of the Indian monsoon.
7. Give an account of weather conditions and characteristics of the cold season.
Answer:
| Feature | Description |
|---|---|
| Period | The cold season begins in mid-November and continues till February. |
| Coldest months | December and January are the coldest months in northern India. |
| Temperature | Temperature decreases from south to north. |
| Northern Plains | Temperature remains around 10°C–15°C. |
| Chennai | Temperature remains around 24°C–25°C. |
| Weather | Days are generally warm and nights are cold. |
| Winds | Northeast trade winds prevail over most parts of India. |
| Tamil Nadu | It receives some winter rainfall because the winds blow from sea to land here. |
| Western Disturbances | They bring winter rainfall to the northern plains and snowfall in the mountains. |
| Rabi crops | Winter rainfall is important for rabi crops. |
The peninsular region does not experience a well-defined cold season because of the moderating influence of the sea.
8. Give the characteristics and effects of the monsoon rainfall in India.
Answer:
The Indian monsoon is pulsating in nature rather than being a steady wind. It generally lasts for 100–120 days, from early June to mid-September.
When the monsoon arrives, rainfall suddenly increases. This is called the ‘burst of the monsoon’.
The monsoon reaches the southern tip of India by the first week of June and then divides into two branches:
| Branch | Main Features |
|---|---|
| Arabian Sea Branch | Reaches Mumbai around 10 June and later covers western and central parts of India. |
| Bay of Bengal Branch | Reaches Assam in the first week of June and moves towards northern India. |
By the end of June, Delhi receives monsoon rainfall. By the first week of July, western Uttar Pradesh, Punjab, Haryana and eastern Rajasthan experience the monsoon. By mid-July, it reaches Himachal Pradesh and the remaining parts of the country.
The monsoon is very important because agriculture, water availability and the life of people in India depend greatly on monsoon rainfall.
