Climate and Vegetation (Class 11 NCERT) here’s a clean, colorful, and student-friendly notes format for Chapter 4: Climate and Vegetation for Class 11 Geography
1. Multiple-Choice Questions (With Explanations)
(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: (c) North-Eastern monsoon ✅
Explanation: In October–November, when the southwest monsoon withdraws, winds reverse direction. The north-eastern monsoon winds blow from land to sea but pick up moisture from the Bay of Bengal, bringing rain to Tamil Nadu’s coast. This is why Tamil Nadu gets winter rainfall instead of summer rainfall.
(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: (d) Three-fourth ✅
Explanation: A large part of north-western India, the Deccan plateau, and parts of central India are rain-deficient. Only some regions, like the Western Ghats, north-east India, and the Himalayan foothills, get heavy rain. About 75% of India’s land gets less than 75 cm of rain yearly.
(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: (d) Extreme climatic conditions are found here ✅
Explanation: South India has a maritime climate due to its proximity to the sea. Temperature variation is low—both daily (diurnal) and yearly (annual). Extreme climate is a feature of continental interiors like north-west India, not of South India.
(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: (a) High pressure develops over North-western India due to low temperatures ✅
Explanation: In December, when the sun is over the Tropic of Capricorn, the northern hemisphere is in winter. NW India cools rapidly, causing high pressure to form. This pressure pattern influences winter winds and the retreat of the monsoon.
(i) What is the Inter-Tropical Convergence Zone (ITCZ)?
Answer:
The Inter-Tropical Convergence Zone (ITCZ) is a low-pressure belt near the equator where the trade winds from the Northern and Southern Hemispheres meet. This convergence causes air to rise, leading to cloud formation and precipitation. The ITCZ shifts north or south following the seasonal movement of the sun.
(ii) What is meant by “bursting of monsoon”? Name the place in India which gets the highest rainfall.
The “bursting of the monsoon” means the sudden arrival of the rainy season. It starts with strong winds, loud thunder, and bright lightning, bringing heavy rain to many places. This sudden change makes the weather cooler. Mawsynram in Meghalaya gets the highest rainfall in India every year.
(iii) Which type(s) of cyclones cause rainfall in north-western India during winter? Where do they originate?
Answer:
Western cyclonic disturbances, originating over the Mediterranean Sea, cause winter rainfall in north-western India. Carried by westerly winds, these systems bring much-needed precipitation to regions like Punjab, Haryana, Delhi, and the lower Himalayas—vital for winter crop cultivation.
Long Answer Question
Q. Notwithstanding the broad climatic unity, the climate of India has many regional variations. Elaborate this statement giving suitable examples.
Answer:
India has a monsoon type of climate, which creates an overall unity in the pattern of seasons—summer, rainy season, and winter occur across the country. However, due to differences in location, relief, altitude, and distance from the sea, there are large variations in temperature, rainfall, and seasons in different regions.
1. Reasons for Regional Variations
- Latitude – Areas near the equator (southern India) are hotter than northern areas.
- Altitude – Hill stations like Shimla are cooler than plains.
- Relief features – The Western Ghats and Himalayas affect rainfall.
- Distance from sea – Coastal areas have mild climate, interiors have extreme climate.
2. Examples of Climatic Variations in India
| Region | Temperature | Rainfall | Reason |
|---|---|---|---|
| Rajasthan (Jaisalmer) | Very hot in summer, very cold in winter | Less than 25 cm | Desert climate, far from sea |
| Mawsynram (Meghalaya) | Warm throughout the year | More than 1100 cm (highest in the world) | Moist monsoon winds + hill barriers |
| Coastal Tamil Nadu | Moderate temperature | Heavy rainfall in Oct–Nov | North-East monsoon winds |
| Ladakh (J&K) | Very cold | Very little rainfall | High altitude, rain shadow area |
3. Conclusion
Though the monsoon unites India’s climate, these regional differences affect agriculture, vegetation, and lifestyle. This diversity makes India’s climate unique—showing unity in pattern but variety in experience.
Q. Describe the distinct seasons in India.
Answer:
India experiences different weather conditions throughout the year. The climate changes due to the movement of the sun, wind, and monsoon. There are four main seasons in India:
| Season | Months | Main Features |
|---|---|---|
| Winter ❄️ | December to February | Cold weather, short days, fog in some areas, snowfall in mountains. |
| Summer ☀️ | March to May | Very hot weather, long days, loo (hot winds) in north India. |
| Monsoon 🌧️ | June to September | Heavy rainfall due to southwest monsoon winds, rivers and lakes get filled. |
| Autumn 🍂 | October to November | Pleasant weather, sky becomes clear, rainfall stops, leaves start falling in some trees. |
Explanation:
These seasons are important for agriculture, lifestyle, and festivals in India. The monsoon season is especially important as it provides water for crops.
DIAGRAMS FOR EXPLORE YOUR UNDERSTANDING
