Class | Subject | Book | Chapter | Session | Questions covered |
|---|---|---|---|---|---|
XI | Geography | India: Physical Environment (NCERT) | 4 – Climate | 2026-27 | 9 of 9 |
Chapter at a glance
Topic | Key points |
|---|---|
Unity and diversity | Monsoon climate gives broad unity; regional variations in temperature, winds and rainfall |
Factors | Latitude, Himalayas, distribution of land and water, distance from sea, altitude, relief; air pressure and winds, jet streams, western disturbances, tropical cyclones |
Monsoon mechanism | Differential heating, shift of ITCZ, Tibetan plateau heating, easterly jet, El Niño, Southern Oscillation |
Onset and burst | Arrives in Kerala around 1 June; “burst” = sudden onset of heavy rain |
Seasons (IMD) | Cold weather (Dec–Feb), hot weather (Mar–May), south-west monsoon (Jun–Sep), retreating monsoon (Oct–Nov) |
Rainfall | Highest: Mawsynram/Cherrapunji; less than 75 cm in about a third of the country; Tamil Nadu gets rain from the north-east monsoon in winter |
Exercise Questions
Question 1 (i)
What causes rainfall on the coastal areas of Tamil Nadu in the beginning of winters?
(a) South-West monsoon (b) Temperate cyclones (c) North-Eastern monsoon (d) Local air circulation
Answer
The north-east (retreating) monsoon picks up moisture over the Bay of Bengal and brings rain to the Coromandel coast in October–December.
- North-Eastern monsoon
Question 1 (ii)
What is the proportion of area of India which receives annual rainfall less than 75 cm?
(a) Half (b) One-third (c) Two-third (d) Three-fourth
Answer
- One-third
Question 1 (iii)
Which one of the following is not a fact regarding South India?
(a) Diurnal range of temperature is less here. (b) Annual range of temperature is less here. (c) Temperatures here are high throughout the year. (d) Extreme climatic conditions are found here.
Answer
South India has a maritime, equable climate because it is surrounded by seas and close to the equator; extreme conditions are not found there.
- Extreme climatic conditions are found here.
Question 1 (iv)
Which one of the following phenomenon happens when the sun shines vertically over the Tropic of Capricorn in the southern hemisphere?
(a) High pressure develops over North-western India due to low temperatures. (b) Low pressure develops over North-western India due to high temperatures. (c) No changes in temperature and pressure occur in north-western India. (d) ‘Loo’ blows in the North-western India.
Answer
When the sun is over the Tropic of Capricorn (December–January), it is winter in the northern hemisphere; north-western India becomes cold and a high-pressure area develops there.
- High pressure develops over North-western India due to low temperatures.
Question 2 (i)
What is the Inter-Tropical Convergence Zone?
Answer
The ITCZ is a low-pressure belt near the equator where the north-east and south-east trade winds converge and air rises. It shifts with the apparent movement of the sun; in July it moves to about 20°–25°N over the Gangetic plain (as the monsoon trough), drawing the south-west monsoon winds into India.
A low-pressure zone near the equator where the trade winds converge; it shifts north in summer (monsoon trough) and draws in the south-west monsoon.
Question 2 (ii)
What is meant by ‘bursting of monsoon’? Name the place of India which gets the highest rainfall.
Answer
Bursting of monsoon is the sudden onset of the south-west monsoon with heavy, continuous rainfall, accompanied by thunder and lightning, in contrast to gradual increase. It happens around 1 June in Kerala.
Highest rainfall: Mawsynram (near Cherrapunji) in the Khasi hills of Meghalaya.
The sudden, heavy onset of monsoon rains (around 1 June in Kerala); Mawsynram in Meghalaya gets the highest rainfall.
Question 2 (iii)
Which type(s) of cyclones cause rainfall in north-western India during winter? Where do they originate?
Answer
Western disturbances — temperate (extra-tropical) cyclones — cause winter rain in north-western India. They originate over the Mediterranean Sea (and West Asia) and are carried eastward by the westerly jet stream through Iran, Afghanistan and Pakistan. The rain helps the rabi crops.
Western disturbances (temperate cyclones) originating over the Mediterranean Sea.
Question 3 (i)
Notwithstanding the broad climatic unity, the climate of India has many regional variations. Elaborate this statement giving suitable examples.
Answer
India has a broadly monsoon climate, giving it unity in the rhythm of seasons. Yet there are large regional variations:
- Temperature: in summer the mercury touches 48°–50°C in western Rajasthan, while it is about 20°C at Pahalgam in Kashmir. In winter Drass (Ladakh) may fall to −45°C, while Thiruvananthapuram has about 22°C.
- Diurnal range: in the Thar desert day temperatures may be 50°C and fall near 15°C at night; in Kerala and the Andaman and Nicobar Islands the difference is small.
- Rainfall amount: Mawsynram/Cherrapunji receive over 1,080 cm, while Jaisalmer gets less than 9 cm a year.
- Type of precipitation: snowfall in the Himalayas; rain elsewhere.
- Season of rainfall: most of India gets rain in June–September, but the Coromandel coast of Tamil Nadu gets most rain in October–November.
- Continentality: coastal areas have equable climates; interior areas have extreme climates.
Despite the unifying monsoon, temperatures (50°C in Rajasthan vs −45°C at Drass), diurnal ranges, rainfall amounts (1,080 cm at Mawsynram vs under 9 cm at Jaisalmer), precipitation type and rainy season (Tamil Nadu in Oct–Nov) vary widely.
Question 3 (ii)
How many distinct seasons are found in India as per the Indian Meteorological Department? Discuss the weather conditions associated with any one season in detail.
Answer
The IMD recognises four seasons:
- Cold weather season (December to February)
- Hot weather season (March to May)
- South-west monsoon season (June to September)
- Retreating monsoon season (October and November)
The cold weather season
- Temperature: temperatures decrease from south to north. In north India the mean January temperature is 10°–15°C; it can fall below freezing in Punjab and Rajasthan at night. In the south, temperatures remain above 20°C.
- Pressure and winds: a high-pressure area forms over north-western India; cold, dry winds blow from land to sea (north-east trade winds). Winds are light.
- Weather: clear skies, low humidity, cool days and cold nights; fog and frost in the north; cold waves follow snowfall in the Himalayas.
- Rainfall: western disturbances from the Mediterranean bring light winter rain to the north-western plains (good for wheat) and snow to the Himalayas; the north-east monsoon brings rain to the Tamil Nadu coast.
Four seasons: cold weather, hot weather, south-west monsoon and retreating monsoon. The cold season has temperatures falling northward, high pressure in the north-west, clear skies, frost and fog, light rain from western disturbances and rain on the Tamil Nadu coast.
Topic checklist
- Unity and diversity in the monsoon climate
- Factors determining India’s climate
- Mechanism, onset, burst and break of the monsoon
- Seasons of India
- Distribution of rainfall; climatic regions; monsoon and economic life