Q 1 – What is climate?
Climate refers to sum total of weather conditions over a large area for a long period of time (30 – 40 years).
Q 2 – Distinguish between climate and weather.
Climate refers to the sum total of weather conditions and variations over a large area for a long period of time (thirty years).
Weather refers to the state of the atmosphere over an area at any point of time.
Q 3 – Name the elements of climate and weather.
Ans. Elements of weather and climate are temperature, atmospheric pressure, wind, humidity and precipitation.
Q 4 – What is the climate of India?
India’s climate is described as a “Tropical Monsoon Type of Climate”.
Q 5 – What does the word ‘Monsoon’ mean?
The word Monsoon is derived from the Arabic word ‘mausim’ which literally means season. It refers to the seasonal reversal in the wind direction during a year.
Q 6 – What is the variation of temperature in summer in India?
In summer, the mercury occasionally touches 50°C in some parts of Rajasthan desert, whereas it may be around 20°C in Pahalgam in Jammu and Kashmir.
Q 7 – What is the variation of annual precipitation in India?
The annual precipitation is over 400 cms in Meghalaya and less than 10 cms in Ladakh and western Rajasthan.
Q 8 – In which months is the season of rainfall experienced in India?
Most parts of India receive rainfall from June to September.
Q 9 – Why do the coastal areas of India experience less contrast in temperature?
The coastal areas experience less contrast in temperature because of the influence of the sea, e.g. Mumbai experiences an equable climate.
Q 10 – Why is there decrease in rainfall from east to west in the Northern Plains?
There is a general decrease in the amount of rainfall from east to west in the Northern Plains as the winds have less moisture in them when they reach the western side.
Q 11 – What does the term continentality mean?
As the distance from the sea increases the moderating influence of the sea decreases and the people experience extreme weather conditions. This is called continentality i.e. very hot in summers and cold in winters, e.g. in Delhi.
Q 12 – Why does the amount of solar radiation vary with latitude?
The amount of solar radiation varies with latitude because of the curvature of the earth. The temperature decreases from the equator to the poles.
Q 13 – How does the temperature decrease with altitude?
The temperature of the air decreases at the rate of 1°C for every 165 m of ascent. This is because the air density decreases with height. That is why hills are cooler in summer.
Q 14 – Which two factors affect the wind and pressure system of an area and how?
The latitude and the altitude of the place affect the temperature and rainfall of the area.
Q 15 – What are ocean currents? Name the two types.
Ocean currents are streams of water that move in the same direction throughout the year. The two types of ocean currents are warm currents and cold currents.
Q 16 – How does the relief of an area affect the climate of a place?
The relief of a place affects the climate of a place when the high mountains act as barriers for cold and hot winds, e.g. the Himalayas. They also affect the amount of rainfall if they are very high. They force the wind to give heavy rain on the windward side and less rain on the leeward side.
Q 17 – Which parallel of latitude passes through the centre of India?
The parallel of latitude is the Tropic of Cancer, 231/2°N.
Q 18 – What is the influence of the division of India by the Tropic of Cancer?
The Tropic of Cancer divides India into the Tropical zone which lies to the south and the sub-tropical area which lies to the north. It gives India’s climate a tropical and sub-tropical character.
Q 19 – What is Coriolis force?
It is an apparent force caused by the earth’s rotation. The Coriolis force is responsible for deflecting the winds to the right in the northern hemisphere and towards the left in the southern hemisphere, due to the rotation of the earth.
Q 20 – What do you know about South-Western Monsoon Winds?
Air moves from the high-pressure area over the southern Indian Ocean in a south-easterly direction, crosses the equator and gets deflected towards the rights towards the low-pressure area over the Indian subcontinent. This is known as south western monsoon.
Q 21 – What are jet streams?
Jet streams are fast flowing winds at high altitude of above 12,000 metres in the troposphere.
Q 22 – What are sub-topical westerly jet streams?
The sub-tropical westerly jet streams are located approximately over 27° – 30° north latitude.
Q 23 – In which parts of India the sub-tropical westerly jet streams blow?
Ans. The sub-tropical westerly jet streams flow south of the Himalayas all through the year except in summers. They are responsible for the western cyclonic disturbances in north and north western parts.
Q 24 – What are tropical easterly jet streams?
An easterly jet stream known as the tropical easterly jet stream blows over peninsular India approximately at 14°N during the summer months.
Q 25 – What are western cyclonic disturbances?
These are shallow cyclonic depressions that originate over the eastern Mediterranean sea, travel eastwards, and influence the weather conditions of northwestern parts of India during winters.
Q 26 – Which warm ocean current replaces the Peruvian cold current?
El Nino.
Q 27 – On what basis is the year divided into seasons?
On the basis of the generalised monthly atmospheric conditions.
Q 28 – What does the word ‘Monsoon’ refer to?
The word ‘Monsoon’ refers to the seasonal reversal in the wind direction during a year.
Q 29 – Where is the monsoonal type of climate found in Asia?
In south and southeast Asia.
Q 30 – Name the two elements which are responsible for the regional variations within the country.
The two important elements are temperature and precipitation.
Q 31 – What is the temperature in Rajasthan in summer?
50°C
Q 32 – Where is Drass located? What are the winter temperatures?
Drass is located in Jammu and Kashmir. The winter temperatures are as low as minus 45°C.
Q 33 – Why do the houses in Rajasthan have thick walls and flat roofs?
The houses in Rajasthan have thick walls to prevent them from becoming hot. The thick walls keep the interior cool. The flat roofs are used to collect water when it rains and in summer they are used for drying dates and storage purposes.
Q 34 – Why are houses in Assam built on stilts?
Assam receives very heavy rain and often water accumulates on the ground. There is a thick undergrowth which makes it difficult for the people to live. So houses are built above the ground level on stilts.
Q 35 – Why do houses in the Terai region, Goa and Mangalore have sloping roofs?
All three regions, the Terai, Goa and Mangalore have very heavy rainfall. The sloping roofs of the houses enable the rainwater to flow off easily.
Q 36 – Why is the climate of India known as having a tropical monsoon character?
Because the climate of India is strongly influenced by the monsoon winds.
Q 37 – How did the sailors who came to India in historic times, benefit from the monsoon winds?
In the olden times the movement of ships depended on the mercy of winds. The sailors and the Arab traders found the monsoon winds helpful, due to the reversal of the wind system.
Q 38 – What is the duration of the monsoon?
100-120 days from June to mid-September.
Q 39 – Explain the term ‘burst’ of the monsoon.
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two branches of the South West Summer Monsoon.
Ans. Bay of Bengal Branch
Arabian sea Branch.
Q 41 – What causes the Bay of Bengal branch of the S.W. Summer Monsoons to be deflected towards the west over the Ganga plains?
Ans. The lofty Himalayas and the low pressure in N.W. India attracts the Monsoons.
Q 42 – Why does the global heat belt shift northwards in the summer season?
Ans. It shifts northwards due to the apparent northward movement of the sun.
Q 43 – Name any two states which are affected by the TVopical cyclones.
Ans. Tamil Nadu, Odisha.
Q 44 – Why do the Monsoon winds change their direction? Give any one reason.
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
Q 45 – Give two examples of pre-monsoon showers.
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 46 – Name the major seasons of India.
Ans.
(a) The cold weather season (winter)
(b) The hot weather season (summer)
(c) Rainy season
(d) Retreating season
Q 47 – Name the three basic elements that one learns about while studying the natural environment of any area.
Ans. The three basic elements are.
(a) Landforms
(b) Drainage
(c) Atmospheric Conditions
Q 48 – What is the form of precipitation in the upper parts of the Himalayas, Meghalaya and western Rajasthan?
Ans.
(a) Upper parts of the Himalayas – snow.
(b) Meghalaya – Rainfall of over 400 cm.
(c) Western Rajasthan – Rainfall of about 10 cm.
Q 49 – When and how do the following parts of the country get their rainfall: Tamil Nadu, Northern Plains.
Ans. (a) Tamil Nadu receives its rainfall in winter from the N E Winter Monsoons and tropical cyclones.
(b) The Northern plains receive rainfall between June and September from the South West Monsoons.
Q 50 – What is the duration of the Summer season?
Ans. March to May.
Q 51 – State the temperature and pressure conditions in the Hot Weather season.
Ans. The summer months experience rising temperature and falling air pressure.
Deccan: 38°C Gujarat and M.P: 42°C N.W. India: 45°C
Q 52 – Name the local winds blowing in summer.
Ans. The Loo, Kaal Baisakhi and Mango showers.
Q 53 – How do the variations in temperature affect the lives of the people in India?
Ans.
(a) They affect the food the people eat.
(b) The clothes the people wear
(c) The kind of houses they live in.
Q 54 – What is the jet stream?
Ans.
(a) These are a narrow belt of high altitude westerly winds in the troposphere.
(b) Their speed varies from about 110 km/h in summer to about 184 km/h in winter.
(c) Of the jet streams that have been identified, the most constant are the mid-latitude and the sub¬tropical jet stream.
Q 55 – What is the ITCZ?
Ans.
(a) The Inter Tropical Convergence Zone is a low pressure trough lying 5° North and South of the Equator.
(b) The North East and the South East Trade winds meet here.
(c) The ITCZ moves north or south of the Equator with the apparent movement of the sun.
Q 56 – Explain the Southern Oscillation.
Ans.
(a) Normally when the tropical eastern South Pacific Ocean experiences high pressure, the tropical . eastern Indian Ocean experiences low pressure.
(b) Sometimes there is a reversal in the pressure conditions.
(c) This periodic change in pressure conditions is known as the Southern Oscillation or S.O. If the pressure differences are negative it would mean late monsoons.
Q 57 – How is the El Nino phenomenon connected with the Southern Oscillation?
Ans.
(a) Normally a cold current flows along the Peruvian Coast.
(b) Every two to five years a warm ocean current takes the place of the cold Peruvian current.
(c) The changes in the pressure conditions are connected to the El Nino, so this phenomenon is referred to as ENSO (El Nino Southern Oscillations).
Q 58 – What do you understand by the ‘Retreating of the Monsoon’? When does it occur?
Ans. (a) Withdrawal of the monsoon from the country is known as the retreating of the monsoon.
(b) The withdrawal is a gradual process. In September the monsoon withdraws from the north western states and by October from the northern half of the peninsular.
(c) The monsoon finally withdraws from the country by early December.
Q 59 – Describe the main features of the Retreating Monsoon season in India.
Ans. The main features of the Retreating Monsoon season in India are:
(a) During October-November the monsoon trough becomes weaker. It is gradually replaced by a high pressure system. The south-west monsoon winds starts withdrawing gradually. By beginning of October the monsoon withdraws completely from northern plains.
(b) The months of October and November are a period of change from hot rainy season to dry winter conditions. The land is moist, the sky is clear and the temperature rises. Nights are cool and pleasant. Owing to high temperature and humidity, the heat becomes oppressive during daytime and it is called ‘October heat’.
(c) The low pressure conditions get transferred over the Bay of Bengal by the beginning of November. This shift is associated with the occurence of cyclonic depression, which develops over the Andaman Sea. These cyclones cross the eastern coast and cause heavy rainfall. They are destructive and the deltas of the Godavari, Krishna and Kaveri are often struck by them.
Q 60 – What are the temperate cyclones? How do they influence the climate of India?
Ans. (a) Temperate cyclone also known as depressions, enter India from the Mediterranean Sea in the cold season.
(b) These cause winter rains over the Northern plains and snowfall in the mountains.
(c) The winter rainfall locally known as ‘mahawat’ is small, but is very important for the cultivation of rabi crops.