Short Answers Type Questions
Q.1. Give two examples of pre-monsoon showers. [CBSE 2016]
Ans. The two examples of pre-monsoon showers are the 'mango showers’ in Kerala and Karnataka and the ‘Kaal Baisakhi’ which causes rainfall in West Bengal.
Q.2. Explain any three factors which affect the mechanism of monsoons. [CBSE 2016]
Ans. The three factors are:
- The presence of land and water causes differences in temperature. This results in differences in pressure which gives rise to the monsoons. The monsoon winds blow from high pressure to low pressure. This determines the direction of winds.
- The movement of the westerly jet stream to the north of the Himalayas and the presence of the easterly jet stream over the peninsula during summer.
- The shift of the position of the Inter-Tropical Convergence zone in summer over the Ganga plain (normal position is about 5°N of the equator).
Q.3. Why do the Monsoon winds change their direction? Give any one reason. [CBSE 2015]
Ans. Monsoon winds change their direction when the lofty Himalayas obstruct their passage. For example, the Himalayas causes the monsoon winds to deflect towards the west over the Ganga Plains.
Long Answers Type Questions
Q.1. Describe the regional variations in the climatic conditions of India with the help of suitable examples. [CBSE 2016]
Ans. There are great variations in the climate of India.
- Certain regions receive very heavy rainfall like the North-east and the Western Coastal plains while others like the Thar Desert receive scanty rainfall.
- Places like Ladakh and Kashmir are very cold while others like Rajasthan are very hot.
- Coastal regions have an equable climate while places in the interior have an extreme climate.
- Areas on the windward slopes of the mountains receive heavy rainfall, while leeward and rain shadow areas receive less rain.
- Coastal areas with warm currents flowing past it will be warmer than those areas which have the cold currents flowing close to it.
Q.2. Describe the role of El Nino and Southern Oscillation to control the climate of India. [CBSE 2016]
- The periodic change in pressure conditions in the eastern Pacific and eastern Indian Ocean is known as the Southern Oscillation.
- The difference in pressure in the Indian and Pacific Oceans is computed to predict the intensity of the monsoons. Negative pressure differences predict below average and late Monsoons.
- This affects the El Nino, a warm current which flows along with the Peruvian current instead of the cold current.
- The changes in pressure conditions are connected to El Nino.
Study the table given above and answer the following questions:
(a) What type of climate does station A have and why?
(b) What type of climate does station B have and why? [CBSE 2016]
Ans. (a) Since station A is located closer to the equator and at a height of 909 m it has a moderate climate.
(b) Station B is located at 26°N in the interior of the country, north of the Tropic of Cancer.
Q.4. Development of tropical cyclones is a distinguishing feature of the monsoon. How do tropical cyclones influence the distribution of rainfall in India? [CBSE 2016]
- The low-pressure conditions over northwestern India slowly get transferred to the Bay of Bengal by early November.
- The occurrence of cyclonic depression is a result of this shift.
- The tropical cyclones move westwards towards the east coast of India and cause heavy rainfall there.
- These cyclones are very destructive and cause great damage to life and property.
- Most of the winter rain along the east coast is caused by these depressions.