EVENTS CONVENT HIGH SCHOOL
05/01/2022 CLASS- 9 SESSION 2021-22
SUBJECT :SOCIAL STUDIES
CHAPTER-4 GEOGRAPHY
CLIMATE
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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
Ans:
(b) Mawsynram
(ii) The wind blowing in the northern plains in summers is known as:
(a) Kaal Baisakhi
(b) Loo
(c) TVade Winds
(d) None of the above
Ans:
(b) Loo
(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
Ans:
(c) Western disturbances
(iv) Monsoon arrives in India approximately in:
(a) Early May
(b) Early July
(c) Early June
(d) Early August
Ans:
(c) 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
Ans:
(c) Cool days and cold nights
2.Answer the following questions:-
Question-1What are the controls affecting the climate of India?
Solution:
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
- Relief features
Question-2Why does India have a monsoon type of climate?
Solution:
The monsoon type of climate is characterised by a distinct seasonal pattern. The weather conditions greatly change from one season to the other. These changes are particularly noticeable in the interior parts of the country. The coastal areas do not experience much variation in temperature though there is variation in rainfall patterns. Four main seasons can be identified in India – the cold-weather season, the hot weather season, the advancing monsoon, and the retreating monsoon with some regional variations.
Question-3Which winds account for rainfall along the Malabar Coast?
Solution:
Surface winds account for rainfall along the Malabar coast.
Question-4What are Jet streams and how do they affect the climate of India?
Solution:
Jet streams are a narrow belt of high altitude (above 12,000 m) westerly winds in the troposphere. Their speed varies from about 110 km/h in summer to about 184 km/h in winter. A number of separate jet streams have been identified. The most constant is the mid-latitude and the subtropical jet stream.
Over India, these jet streams blow south of the Himalayas, all through the year except in summer. The western cyclonic disturbances experienced in the north and northwestern parts of the country are brought in by this westerly flow. In summer, the subtropical westerly jet stream moves north of the Himalayas with the apparent movement of the sun. An easterly jet stream, called the tropical easterly jet stream blows over peninsular India, approximately over 14°N during the summer months.
Question-5Define monsoons. What do you understand by “breaks” in monsoon?
Solution:
The seasonal reversal in wind direction during a yeat is called the monsoon. Monsoon tends to have ‘breaks’ in rainfall; which means that there are wet and dry spells in between The monsoon rains take place only for a few days at a time and then come to the rainless intervals.
Question-6Why is the monsoon considered a unifying bond?
Solution:
Despite great moderating influences on the climate of India, there are great variations in the temperature conditions. Nevertheless, the unifying influence of the monsoon on the Indian subcontinent is quite perceptible. The seasonal alteration of the wind systems and the associated weather conditions provide a rhythmic cycle of seasons.
Question-7Why does the rainfall decrease from the east to the west in Northern India?
Solution:
The western coast and northeastern India receive over about 400 cm of rainfall annually. However, it is less than 60 cm in western Rajasthan and adjoining parts of Gujarat, Haryana, and Punjab. Rainfall is equally low in the interior of the Deccan plateau, and east of the Sahyadris. The third area of low precipitation is around Leh in Jammu and Kashmir. The rest of the country receives moderate rainfall.
Snowfall is restricted to the Himalayan region. Owing to the nature of monsoons, the annual rainfall is highly variable from year to year. Variability is high in the regions of low rainfall such as parts of Rajasthan, Gujarat and the leeward side of the Western Ghats. As such, while areas of high rainfall are liable to be affected by floods, areas of low rainfall are drought-prone.
Question-8Give reasons as to why.
(i) The bulk of rainfall in India is concentrated over a few months.
(ii) The Tamil Nadu coast receives winter rainfall.
Solution:
(i) The bulk of rainfall in India is concentrated over a few months
The inflow of the south-west monsoon into India brings about a total change in the weather. Early in the season, the windward side of the Western Ghats receives very heavy rainfall, more than 250 cm. The Deccan Plateau and parts of Madhya Pradesh also receive some amount of rain in spite of lying in the rain shadow area. The maximum rainfall of this season is received in the north-eastern part of the country. Mawsynram in the southern ranges of the Khasi Hills receives the highest average rainfall in the world. Rainfall in the Ganga valley decreases from the east to the west. Rajasthan and parts of Gujarat get scanty rainfall.
(ii) The Tamil Nadu coast receives winter rainfall
A characteristic feature of the cold weather season over the northern plains is the inflow of cyclonic disturbances from the west and the northwest. These low-pressure systems, originate over the Mediterranean Sea and western Asia and move into India, along with the westerly flow. They cause the much-needed winter rains over the plains and snowfall in the mountains. Although the total amount of winter rainfall locally known as ‘mahawat’ is small, they are of immense importance for the cultivation of ‘rabi’ crops. The peninsular region does not have a well-defined cold season. There is hardly any noticeable seasonal change in temperature patterns during winters due to the moderating influence of the sea.
Question-9Describe the regional variations in the climatic conditions of India with the help of suitable examples.
Solution:
Despite an overall unity in the general pattern, there are perceptible regional variations in climatic conditions within the country. The two important elements, which cause these variations, are – temperature and precipitation.
For example, in summer, the mercury occasionally touches 50°C in some parts of the Rajasthan desert, whereas it may be around 20°C in Pahalgam in Jammu and Kashmir. On a winter night, the temperature at Drass in Jammu and Kashmir may be as low as minus 45°C. Tiruvananthapuram, on the other hand, may have a temperature of 20°C.