UP Board Solutions for Class 9 Social Science Geography Chapter 4 Climate

UP Board Solutions for Class 9 Social Science Geography Chapter 4 Climate Textbook Questions and Answers, Additional Important Questions

UP Board Class 9 Geography Chapter 4 Climate InText Questions and Answers

Activity and In-text Questions :

Find Out (Page No. 27)

Question 1.
Why the houses in Rajasthan have thick walls and flat roofs ?
Answer:
Rajasthan has very hot climate. During summers, sun rays fall straight to the land because of absence of forests. The occurrence of sand storms are quiet frequent which blow at a great speed. It is an arid zone having the great Indian desert. Due to such climatic conditions, the walls of houses in Rajasthan are made thick, so they take longer time to get heated up. This keeps the cool and : low temperature inside the house. At the same time, houses have flat roofs, so that they do not get damaged or blow up during the stopms.

Question 2.
Why is it that the houses in the Tarai region, and in Goa and Mangalore have sloping roofs ?
Answer:
Tarai region, Goa and Mangalore are all located in the heavy rainfall areas. Goa and Mangalore receive more than 300-400 cm rainfall and Tarai region receive 100-200 cm rainfall. That is why, the roofs of the houses are kept sloppy, so that the water do not get collected on the roofs and can easily flow down from slanting roofs.

Question 3.
Why are houses in Assam built on stilts ?
Answer:
Assam receives heavy rainfall, about 300 cm in a year. It results in the occurrence of floods. That is why, the houses are made on stilts, so that the water may not enter into the houses.

Find Out (Page No. 27)

Question 1.
Why most of the world’s deserts are located in the western margins of continents in the subtropics ?
Answer:
Most of the rainfall in the continents of the subtropics is the result of trade winds which blow from the north-east to the south-west. When they rise in east of the continents, they are loaded with moisture. This water is lost by the clouds, in the form of precipitation, by the time they reach to the western part of continent. And thus, the western margins remain rainless and, therefore, are the homes of world’s largest deserts.

Activity (Page No. 38)

Question 1.
(i) On the basis of the news items given on the textbook page 38, find out the names of places and the seasons described.
Answer:

(ii) Compare the rainfall description of Chennai and Mumbai and explain the reasons for the difference.
Answer:
(1) (i) Mumbai receives more rainfall in summer from Arabian Sea branch from June to September.
(ii) Mumbai is located on the Western coast which comes in the way of Arabian Sea branch at its earliest. It is located on the wind¬ward side of the Western Ghats which receives very heavy rainfall, more than 250 cm.

(2) (i) Chennai is located on the leeward side of the Western Ghats which obstructs the south-west monsoon. Bay of Bengal branch moves parallel to the eastern coast where Chennai is located. So, it does not receive rainfall from this branch.
(ii) Chennai receives rainfall from north-east monsoon and cy¬clones during winters i.e., from October to December.
(iii) Evaluate flood as a disaster with the help of a case study.
Note : Students do it yourself.

For doing it Yourself (Page No. 40-41)

Question 1.
In Table I (given in Textbook on Page 41), the average mean monthly temperatures and amounts of rainfall of ten representative stations have been given. It is for you to study on your own and convert them into ‘temperature and rainfall’
Answer:

Question 2.
Re-arrange the ten stations in two different sequences:
(i) According to their distance from the equator.
Answer:
(i) Thiruvananthapuram : 8° 29’N
(ii) Bangalore : 12° 58′ N
(iii) Chennai : 13° 4′ N
(iv) Mumbai: 19°N
(v) Nagpur : 21° 9′ N
(vi) Kolkata : 22° 34′ N
(vii) Shillong :.24° 34′ N
(viii) Jodhpur : 26° 18′ N
(ix) Delhi : 29°N
(x) Leh : 34°N

(ii) According to their altitude above mean sea-level.
Answer:
(i) Kolkata
(ii) Chennai
(iii) Mumbai
(iv) Thiruvananthapuram
(v) Delhi
(vi) Jodhpur
(vii) Nagpur
(viii) Bangalore
(ix) Shillong
(x) Leh.

Question 3.
(i) Name two rainiest stations.
Answer:
(a) Shillong
(b) Mumbai

(ii) Name two driest stations.
Answer:
(a) Leh
(b) Jodhpur

(iii) Two stations with most equable climate.
Answer:
(a) Mumbai
(b) Thiruvananthapuram

(iv) Two stations with most extreme climate.
Answer:
(a) Delhi
(b) Nagpur

(v) Two stations most influenced by the Arabian branch of south-west monsoons.
Answer:
(a) Mumbai
(b) Bangalore

(vi) Two stations most influenced by the Bay of Bengal branch of south-west monsoons.
Answer:
(a) Shillong
(b) Kolkata

(vii) Two stations influenced by both branches of the south¬west monsoons.
Answer:
(a) Thiruvananthapuram
(b) Kanyakumari .

(viii) Two stations influenced by re-treating and north¬east monsoons.
Answer:
(a) Chennai
(b) Coastal regions of Andhra Pradesh

(ix) Two stations receiving winter showers from the western disturbances.
Answer:
(a) Delhi
(b) Leh (in the form of snowfall)

(x) The two hottest stations in the months of
(a) February
(b) April
(c) May
(d) June
Answer:
(a) February
(i) Chennai
(ii) Thiruvananthapuram

(b) April –
(i) Chennai
(ii) Nagpur

(d) June –
(i) Delhi
(ii) Jodhpur

Question 4.
Now find out
(i) Why are Thiruvananthapuram and Shillong rainier in June than in July ?
Answer:
In the first week of June, the south-west monsoon enters into India from the south. Thiruvananthapuram being located at the south-emmost part of India falls in the way of monsoon winds at the earliest. Similarly, Shillong falls first in the way of the Bay of Bengal branch. That is why, these two places receive more rain during June. In the month of July, the monsoon winds gradually move in the interior of the Indian lapd-mass.

(ii) Why is July rainier in Mumbai than in Thiruvananthapuram ?
Answer:
By the month of July, the monsoon winds already pass away from Thiruvananthapuram and enter into the interior parts of India causing rainfall. Whereas in Mumbai, the monsoon winds rising from Arabian Sea continuously pours rain due to the presence of Western Ghats.

(iii) Why are south-west monsoons less rainy in Chennai ?
Answer:
For south-west monsoons, Chennai is considered as a rainshadow region, as it lies to the east (leeward side) of the Western Ghats.

(iv) Why is Shillong rainier than Kolkata ?
Answer:
In Shillong, the Garo, Khasi and Jaintia hills trap the monsoon winds and force them to shed moisture. But in Kolkata, the monsoon winds reach comparatively late and there is no such hills located in West Bengal which could trap the monsoon winds.

(v) Why is Kolkata rainier in July than in June unlike Shillong which is, rainier in June than in July ?
Answer:
Kolkata is rainier in July than June because, monsoon winds reach there in July. But in Shillong the monsoon winds reach in the month of June and cause heavy rainfall. It is because, Shillong comes first in the way of monsoon winds, it receives more rainfall in June than in July. Kolkata comes later so, it is more rainier in July than in June.

(vi) Why does Delhi receive more rain than Jodhpur ?
Answer:
Jodhpur lies to the west of Delhi. It means, the monsoon winds first reach at Delhi, then at Jodhpur where they become almost dry.
Delhi receives rainfall from monsoon winds as well as western disturbances, whereas Jodhpur receives rainfall only from monsoon winds that is too very scarce.

Question 5.
Now think why
(i) Thiruvananthapuram has equable climate ?
Answer:
Thiruvananthapuram has equable climate because it lies on the coast.

(ii) Chennai has more rains only after the fury of monsoon is over in most parts of the country ?
Answer:
Most parts of India receive rainfall from the south-west monsoon, whereas Chennai receives rainfall from retreating or north-east monsoons.

(iii) Jodhpur has a hot desert type of climate ?
Answer:
Jodhpur has a hot desert type of climate because, it receives very less amount of rainfall. When the monsoon winds reach in this region they become almost dry.

(iv) Leh has moderate precipitation almost throughout the year ?
Answer:
Because it is located on a higher altitude.

(v) While in Delhi and Jodhpur most of the rain is confined to nearly three months, in Thiruvananthapuram and Shillong it is almost nine months of the year ?
Answer:
Delhi and Jodhpur are located in the interior part of India, where monsoon winds reach very late and also withdraw at the earliest. Whereas, Thiruvananthapuram and Shillong are the places where monsoon arrive at the earliest and continue till they leave the Indian landmass.

(vi) In spite of these facts see carefully if there are strong evidences to conclude that the monsoons still provide a very strong framework lending overall climatic unity to the whole country.
Answer:
The south – west monsoons, together with the Himalayan mountain wall, give tropical touch to the Indian subcontinent. India is a monsoon country – the best example of a monsoon land. Despite climatic contrasts from region to region, monsoons provide a rhythmic cycle of seasons, year after year, in India.

UP Board Class 10 Geography Chapter 4 Climate Textbook Questions and Answers

Exercises Of Ncert (Page No. 39)

Question 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
Answer:
(b) Mawsynram.

(ii) The wind blowing in the northern plains in summers is known as:
(a) Kaal Baisakhi
(b) Loo
(c) Trade Winds
(d) None of the above
Answer:
(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
Answer:
(c) Western disturbances.

(iv) Monsoon arrives in India approximately in :
(a) Early May
(b) Early July
(c) Early June
(d) Early August
Answer:
(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
Answer:
(b) Warm days and cold nights.

Question 2.
Answer the following questions briefly :
(i) What are the controls affecting the climate of India ? Ans. The controls affecting the climate of India are—
(i) Latitude
(ii) Altitude
(iii) Pressure and winds (Jet streams)

(ii) Why does India have a monsoon type of climate ?
Answer:
The differential heating and cooling of land and water creates low pressure on the land mass of India while, the seas around experience comparatively high pressure. This causes a complete reversal of the direction of winds during the summer. Moisture laden winds move from the high pressure area over the southern Indian Ocean and bring widespread rainfall over the mainland of India.

(iii) Which part of India does experience the highest diurnal range of temperature and why ?
Answer:
In India, Thar Desert experiences the highest diurnal range of temperature because of the lack of water. Sandy soil cannot retain moisture or absorb sunlight. When the sun shines, only the ground’s temperature increases. Similarly, during night the desert cools fasterly because dry ground does not retain heat and atmosphere lacks in water vapour, so dry air allows the surface to lose radiation to outer space.

(iv) Which winds account forj’ainfall along the Malabar coast ?
Answer:
The retreating monsoon winds bring heavy rainfall along the Malabar coast.

(v) What are diet streams and how do they affect the climate of India ? (CBSE, 2011-SA2, 04/Bl,06/Bl,25/Al)
Answer:
(1) Jet streams are a narrow belt of high altitude (above 12,000 metres) westerly winds in the troposphere. Their speed varies from about 110 km/h in summer to about 184 km/h in winter.

(2) (i) They help in bringing the western disturbances to north and north western parts of India.
(ii) They bring winter rains over north and north western parts of India. They are important for rabi crop.
(iii) Define monsoons. What do you understand by “break” in monsoon ?
Or
Define monsoon. Differentiate between ‘Burst of the monsoon’ and ‘Break of the monsoon.’ (CBSE, 2011-SA2, 14/A1)
Answer:
(1) Monsoon refers to the seasonal reversal in the wind direction during a year.
(2) (i) Burst of the monsoon: When monsooh arrives in India, the normal rainfall increases suddenly and continues constantly for several days. This is known as the ‘burst of the monsoon’.

(ii) Break of the monsoon : Monsoon’s tendency is to have “breaks’ in rainfall. Thus, it has wet and dry spells. In other words, the monsoon rains take place only for a few days at a time. They are interspersed with rainless intervals. (2016-6QDR56Y)
Or
‘Monsoon has great influence over our social and cultural life.’ Do you agree ? Give any five arguments in support of
your answer. (2016-8SPAMB2; 2015-BALUBOA)
Answer:
Roles of monsoon as a unifying bond in India are as follow:
(1) The Himalayas protect the sub-continent from extremely cold winds from central Asia. This enables northern India to have uniformly higher temperatures as compared to other areas on the same latitude.
(2) It provides a rhythmic cycle of season.
(3) The Indian landscape, its animal, plant life, its entire agricultural calendar, life of people, including their festivals, all depend on monsoon.
(4) The monsoon provides water for the whole country.
(5) Rivers which carry rain water also unite as a single river valley unit.

Question 3.
Why does the rainfall decrease from the east to the west in Northern India?
Answer:
Due to the triangular shape of peninsular India, the south west monsoon divides into two – the Arabian Sea branch and the Bay of Bengal branch. The moisture laden Bay of Bengal branch rushes towards the north-east and gets trapped into the hills present over there. It sheds its maximum moisture over this region. As the monsoon moves westward, it gradually loses moisture. Thus, rainfall decreases from east to west in the Northern India.

Question 4.
Give reasons as to why :
(i) Seasonal reversal of wind direction takes place over the Indian subcontinent.
Answer:
During the winter season, a high pressure area prevails in the north of the Himalayas. Cold-dry winds blow from the north to the south. In summers, the land gets more heated than water, hence, a low pressure area develops over the interior landmass. Hence, winds start blowing from the high pressure area, located over the Indian ocean in the south, to the low pressure areas of the north. There is a complete reversal of wind direction.

(ii) The bulk of rainfall in India is concen-trated over a few months.
Or
Why is the distribution of rainfall in India uneven ? Give four reasons. (CBSE, 2011-SA2, 06/A1,08/Cl)
Or
‘Rainfall is unevenly distributed in India’. Justify in four points. (CBSE, 2011-SA2, 29/BI)
Answer:
(1) The monsoons are not steady winds but are pulsuating in nature. The duration of the monsoon is between 100-120 days from early June to mid-September.
(2) The topography of India leads to more rainfall in some regions while less in others. Himalayas receive precipitation in the form of snow because of higher altitude.
(3) Areas which come first in the way of moisture laden winds; receive more rainfall than the area which comes last of all. For example, western coast and north-eastern India come first in the way of Arabian Sea branch and Bay of Bengal Branch respectively. So, they receive 400 cm of rainfall. Rajasthan comes in the last, so, it receives scanty rainfall.
(4) Areas which have no mountain to work as barriers get scanty rainfall, like, Rajasthan receives less than 60 cm of rainfall. Areas of rain shadow do not get much rainfall, for example, eastern part of Western Ghats.
(5) Whole of India does not receive rain by monsoon winds. Eastern coast of India gets rain only from north-east monsoons during the months of December-January.
(6) Cyclones help rain scatter at places, while other places remain without rain.

(iii) The Tamil Nadu coast receives winter rainfall.
Answer:
During the cold weather season, the north-east trade winds prevail all over the country. They blow from land to sea and hence for most part of the country, it is a dry season. The Tamil Nadu coast, however, gets most of its rain from these winds as they reach here from sea to land.

(iv) The delta region of the eastern coast is frequently struck by cyclones.
Answer:
The low-pressure conditions which once prevailed over north-western India get transferred to the Bay of Bengal by early November. This shift is associated with occurrence of cyclonic depressions which originate over the Andaman Sea. Those that manage to cross the eastern coast of India cause heavy and widespread rains. These tropical cyclones are often very destructive. The deltas of Godavari, the Krishna and the Kaveri lying on the eastern coast are frequently struck by cyclones.

(v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought-prone. (Annual Exam. (Delhi), 2009)
Answer:
Parts of Rajasthan and Gujarat which are lying on the extreme west are drought-prone because by the time the monsoon winds reach in this region they become almost dry. The leeward side of the Western Ghats lies in the rainshadow area. ;

Question 5.
Describe the regional variations in the climatic conditions of India with the help of suitable examples.
Or
India has diverse climatic conditions.” Explain by giving two examples each of temperature and precipitation. (CBSE, 2011-SA2, 04/BI)
Answer:
(1) 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.
(2) On a winter night, temperature at Drass in Jammu and Kashmir may be as low as minus 45°C. Thiruvananthapuram, on the other hand, may have a temperature of 22°C.
(3) The annual precipitation varies from over 400 cm in Meghalaya to less than 10 cm in Ladakh and western Rajasthan.
(4) Most parts of the country receive rainfall from June to September. But, some parts like the Tamil Nadu coast gets a large ‘ portion of its rain during October and November.
(5) While precipitation is mostly in the form of snowfall in the upper parts of Himalayas, it rains over the rest of the country.
(6) Coastal areas experience less contrasts in temperature conditions. Seasonal contrasts are more in the interior of the country.
(7) There is decrease in rainfall generally from ease to west in the Northern plains.

Question 6.
Discuss the mechanism of monsoons.
Or
Describe the mechanism of monsoon. (CBSE, 2011-SA2, 29/A1,32/Bi)
Or
Describe any three facts which affect the mechanism of monsoons. (CBSE, 2011-SA2, 11/BI)
Answer:
(1) The differential heating and cooling of land and water, creates low pressure on the landmass of India while, the seas around experience comparatively high pressure.

(2) The shift of the position of Inter Tropical Convergence Zone (ITCZ) jn summer, over the Ganga plain (This is the equatorial trough normally positioned about 5°N of the equator. It is also known as the monsoon-trough during the monsoon season).

(3) The presence of the high-pressure area, east of Madagascar, approximately at 20°S over the Indian Ocean. The intensity and position of this high-pressure area affects the Indian monsoon. The Tibetan plateau gets intensely heated during summer, which results in strong vertical air currents and the formation of low pressure over the plateau at about 9 km above sea level.

(4) The movement of the westerly Jet Stream to the north of the Himalayas and the presence of the tropical easterly Jet Stream over the Indian peninsula during summer.

Question 7.
Give an account of weather conditions and characteristics of the cold season.
Answer:
(1) Cold weather season prevails from November to February.
(2) The temperature decreases from south to the north.
(3) Days are warm and nights are cold.
(4) The northeast trade winds prevail over the country. From these winds, some amount of rainfall occurs on the Tamil Nadu coast.
(5) The weather is marked by clear sky, low temperatures and low humidity and feeble, variable winds.
(6) Low-pressure systems originate over the Mediterranean Sea and move into India, along with the westerly flow. They cause the much-needed winter rains over the plains and snowfall in the I mountains.

Question 8.
Give the characteristics and effects of the monsoon rainfall in India.
Answer:
The characteristics and effects of the monsoon rainfall in ! India are as follows :
Characteristics :
(i) Uncertainty – The monsoons are very often found irregular (uncertain) in their arrival (onset) as well as withdrawal.
(ii) Variation in the amount – There is a great variation in the amount of rainfall received at different places in India from year to year. It may vary from 15 per cent to 80 per cent.
(iii) Variation in amount from region to region – The monsoons do not give equal amount of rainfall to all parts of India. It varies from less than 10 cm in the Thar Desert to over 1,000 cm in Cherrapunji.
(iv) Variation in duration -The duration of monsoons or the summer monsoons varies from less than two months in the Western Rajasthan to over six months in Kerala or the Andaman and Nicobar Islands.
(v) Long dry spells – A spell of continuous heavy rains is often followed by a long period of no rains at all. ‘
Effects :
(i) Farming – Monsoon’s early or late arrival/withdrawal affects the entire farming schedule of the millions of farmers all over the country.
(ii) Problem of recurring floods and droughts – Continuous heavy rains cause floods. The failure of the monsoon results in droughts in some parts of the country.
(iii) Cycle of seasons – Despite climatic contrasts from region to region, monsoons provide a rhythmic cycle of seasons, year after year in India.
(iv) Cultural life – The monsoons influence the total life of
people-their festivities, music, literature, etc.
(v) The monsoons affect the whole landscape, animal and plant life.

Topicwise Questions Introduction

3/5 Marks Questions

Question 1.
What are the elements of weather and climate ? Distinguish between weather and climate. (2011-34/A1)
Or
Distinguish between weather and climate. Name the type of Indian climate.
Or
Which are the two important elements of climate ? Give one example of each element, from Indian climatic condition. (2015-2CYWIOX, ONWVSDK)
Answer:
(1) The elements of weather and climate are : temperature, atmospheric pressure, wind, humidity and precipitation.
(2) Difference between weather and climate :
(i) Weather refers to the state of the atmosphere over an area at any point of time.
(ii ) Climate refers to the sum total of weather conditions and variations over a large area for a long period of time (more than thirty years).

Question 2.
Why is it so that temperature in Rajasthan soars so high during summer time as compared to Thiruvananthapuram ? (2016-DG5NMSJ)
Answer:
(1) In summer, the mercury occasionally touches 50°C in some part of Rajasthan because during summers, sunrays fall straight to the land due to absence of forests.
(2) Thiruvananthapuram, on the other hand, may have a temperature of 22°C, because it lies in coastal areas.
(3) Coastal areas experience less contrasts in temperature conditions. Seasonal contrasts are more in the interior of the country.

Climatic Controls

3/5 Marks Question

Question 1.
Mention any six important factors that control climate of a place. (2015-9L9UC72)
Or
Explain the factors responsible for the control of the climate of the world. (2016-1W84B6K)
Or
Give an account of spatial variations in climatic conditions within India. (2016-8BJGMDQ; 2015-N3MZ1TF)
Or
Explain the factors responsible for the control of the climate of the world. (2016-ONEOSIT; 2015-HEUWPLZ)
Answer:
(1) Due to the curvature of the earth, the amount of solar energy received, varies according to latitude. As a result, air temperature generally decreases from the equator towards the poles.
(2) As one goes from the surface of the earth to Higher altitudes, the atmosphere becomes less dense and temperature decreases. The hills are therefore, cooler during summer.
(3) The pressure and wind systems of any area depend on the latitude and altitude of the place. Thus, they influence the temperature and rainfall pattern.
(4) The sea exerts a moderating influence on climate. As the distance from the sea increases, its moderating influence decreases and the people experience extreme weather conditions.
(5) Relief also plays a major role in determining the climate of a place. High mountains act as barriers for cold or hot winds. They may also cause precipitation if they are high enough and lie in the path of rain-bearing winds.
(6) Ocean currents along with onshore winds affect the climate of the coastal areas. For example, any coastal area with warm or cold currents flowing past it, will be warmed or cooled if the winds are onshore.

Factors Affecting India’S Climate

3/5 Marks Questions

Question 1.
How do Jet Streams influence the climate of India? (2015-WYVWERA; 2014-03QSWGH)
Or
What are Jet Streams ? How do they affect the climate of India ? (2011-04/BI, 06/BI, 25/A1; 2016-6QY5YO)
Answer:
(1) Jet streams are located approximately over 27°-30° north latitude, therefore, they are known as sub-tropical westerly jet streams.
(2) Over India, jet streams blow south of the Himalayas, all through the year except in summer.
(3) The western cyclonic disturbances experienced in the north and north-western parts of the country are brought in by this westerly flow.
(4) In summer, the sub-tropical westerly jet stream moves north of the Himalayas with the apparent movement of the sun.
(5) An easterly jet stream, called the sub-tropical easterly jet stream blows over peninsular India, approximately over 14°N during the summer month.

Question 2.
Explain the factors that influence the climate of India. (2015-6F8GLJL; 2012-1011, 48020)
Or
State any three atmospheric conditions which govern the climate and associated weather conditions in India. (2012-48036)
Answer:
(1) The locational and relief features :
The Tropic of Cancer passes through the middle of India. Therefore, India’s climate has characteristics of tropical as well as sub-tropical climates. India has mountains to the north, which have an average height of about 6,000 metres. The Himalayas prevent the cold winds from Central Asia from entering the sub-continent.

(2) Pressure and surface winds :
During winter, there is a high-pressure area north of the Himalayas. Cold dry winds blow from this region to the low-pressure areas over the oceans to the south. In summer, a low-pressure area develops over north-western India. This causes a complete reversal of the direction of winds during summer. Air moves from the high-pressure area over the southern Indian Ocean, in a south-easterly direction. These winds bring widespread rainfall over the mainland of India.

(3) Upper air circulation :
(i) The upper air circulation over India is dominated by a westerly flow. An important component of this flow is the Jet Stream.
(ii) These Jet Streams blow south of the Himalayas, all through the year except in summer.
(iii) The western cyclonic disturbances experienced in the north and north-western parts of the country are brought in by this westerly flow.

Question 3.
“Pressure and wind conditions over India are unique”. Give any three examples to support this statement. (2012.48012)
Or
Evaluate the role of pressure and wind system in the development of monsoon. (2016-01A3E0X)
Answer:
(1) During winter, there is a high-pressure area north of Himalayas. Cold winds blow from here to low-pressure areas over oceans towards the south.
(2) There is a complete reversal in the direction of winds during summers. Air moves from high-pressure areas to low-pressure areas as South-west Monsoon winds.
(3) The winds collect moisture from warm oceans and cause rainfall over Indian mainland.

The Indian Monsoon

3/5 Marks Questions

Question 1.
Describe any five distinguishing features of monsoon (2016-HDLKF8K; 2014-C8RWYZI)
Or
Explain three characteristic features of Indian Monsoon. (2014-43CEJVS)
Or
Describe any five distinguishing features of monsoon rainfall in India. (2016-3P77UDN)
Answer:
(1) The sailor who came to India in historic times were the first to have noticed the phenomenon of the monsoon. They benefited from the reversal of wind system as they came by sailing ships at the mercy of winds.
(2) The monsoons are experienced in the tropical area roughly between 20° North and 20° South. It has been noticed that changes in the pressure conditions over the southern oceans also affect monsoon.
(3) Normally, when the tropical eastern South Pacific Ocean experiences high pressure, the tropical eastern Indian Ocean experiences low pressure. But in certain years, there is a reversal in the pressure conditions and the eastern Pacific Ocean has lower pressure in comparison to the eastern Indian Ocean.
(4) This periodic change in pressure conditions is known as the Southern Oscillation.
(5) If the pressure differences were negative, it would mean below average and the late monsoon.

Question 2.
Describe the mechanism of monsoons.(2015-NH5M5QT; 2012-48019; 2011-29/A1)
Or
Describe the factors which help us to understand the mechanism of monsoon. (2016-Z44C6EO)
Answer:
Mechanism of monsoons :
(1) The differential heating and cooling of land and water, create low pressure on the landmass of India while the seas around experience comparatively high pressure.
(2) The position of Inter Tropical Convergence Zone (ITCZ) m summer shifts over the Ganga plain. This is the equatorial trough normally positioned about 5°N of the equator. It is also known as the monsoon-trough during the monsoon season.
(3) The high-pressure area exists east of Madagascar, approximately at 20°S over the Indian Ocean. The intensity and position of this high-pressure area affect the Indian monsoon.
(4) The Tibetan plateau gets intensely heated during summer, which results in strong vertical air currents and the formation of low pressure over the plateau at about 9 km above sea level.
(5) The movement of the westerly Jet Stream to the north of the Himalayas and the presence of the tropical easterly Jet Stream over the Indian peninsula during summer.

The Onset Of The Monsoon And Withdrawal

3/5 Marks Questions

Question 1.
What do you mean by ‘Burst of monsoon’ ?
Or
Explain the term ‘burst’ with reference to Indian Monsoon. (2015-CG2ZHW3)
Answer:
(1) The duration of the monsoon is between 100-120 days from early June to mid-September.
(2) Around the time of its arrival, the normal rainfall increases suddenly and continues constantly for several days.
(3) This is known as the ‘burst of the monsoon’, and can be
distinguished from the pre-monsoon showers. .

Question 2.
Describe the onset of monsoon in Indian context. (2O16-0SSW7H6)
Answer:
(1) During the early days of June, there develops an intensive low pressure condition over the northern plains. This attracts the trade winds of the southern hemisphere.
(2) These trade winds originate over the warm sub-tropical areas of the southern oceans and cross the equator. These blow in a south¬westerly direction entering the Indian peninsula as the south-west monsoon.
(3) As these winds blow over warm oceans, they bring abundant moisture to the subcontinent and within a month cover whole country except the extreme north-west.

The Season

3/5 Marks Questions

Question 1.
Highlight the main features of cold weather season in India. Mention any three points. .
Or
Describe five characteristic features of the cold weather season in India. (2016-3N8J6MA)
Or
Write the chief characteristics of the cold weather season in India. (2014-V1DFTMD, YU0ZDFF)
Answer:
Following are the features of cold weather season in India :
(1) Duration of this season is mid-November in the northern plains and stays till February. December and January are the coldest months in the northern parts of the country.
(2) The temperature decreases from south to north. The days are warm and nights are cold.
(3) Frosts are common in the north and the higher slopes of the Himalayas experience snowfall.
(4) North-east trade winds blow over the country. They blow from land to sea. For most part of the country it is dry season. Some amount of rainfall occurs on the coast of Tamil Nadu from these winds as here, they blow from sea to land.
(5) In the northern part of the country, a feeble high-pressure region develops, with light winds moving outwards from this area.

Question 2.
Differentiate between the cold weather season and the hot weather season of India by explaining two distinctive features of each. (2011-04/A1)
Or
Distinguish between the cold weather seasons and the hot weather seasons. (2016-U51G8YW)
Answer:
(1) Cold weather season :
(i) The cold weather season begins from mid-November in northern India and stays till February.
(ii) The temperature decreases from south to the north. The average temperature of Chennai, on the eastern coast, is between 24°C-25°C, while in northern plains, it ranges between 10°C-15°C.
(iii) Days are short and warm while nights are long and cold.
(iv) The weather is marked by clear sky, low temperatures and lo w humidity and feeble, variable winds. The total amount of winter rainfall is locally known as ‘Mahawaf. It is of immense importance for the cultivation of rabi crop.

(2) Hot weather season :
(i) The hot weather season prevails from March to May.
(ii) The summer months experience rising temperature and falling air pressure in the northerrj part of the country.
(iii) Days are hot and long and nights are warm and short.
(iv) Strong, gusty, hot, dry winds blow over the north and north¬western India. In this season local thunderstorms, associated with violent winds, torrential downpours, often accompanied by hail are common. In West Bengal, these storms are known as the ‘Kaal Baisakhi’. Pre-monsoon showers are common in Kerala and Karnataka. They help in the early ripening of mangoes.

Question 3.
Describe five characteristic features of the hot weather season in India. (2016-9AGOTXP)
Or
Describe main characteristics of the hot weather seasons in India. (2016-6RG3MN9, Y8E5VI0)
Or
Explain the features of the hot weather season in India. (2011-25/A1; 2012-48038, 41)
Answer:
(1) Hot weather season prevails from March to May in India.
(2) Due to apparent northward movement of the Sun, the heat belt shifts northwards. As a result, temperature increases in northern plains.
(3) There is a rise in temperature and fall in air pressure in the northern parts of the country.
(4) Towards the end of May, a low-pressure area develops in the region extending from the Thar Desert in the north-west to Chhotanagpur Plateau in the east.
(5) In the Peninsular India, temperature remains lower due to the moderating influence of the oceans.
(6) The local winds which blow during summers in different parts of India are Loo, Kaal Baisakhi and Mango showers.

Question 4.
Define ‘Kaal Baisakhi’ and ‘Loo’. In which parts India are they experienced ? (2011-34/A1)
Or
Define ‘Kal Baisakhi’, ‘Mango Showers’ and ‘Loo’ ? (2012-48031)
Answer:
(1) Kaal Baisakhi : These are local thunderstorms associated with violent winds, torrential downpours, often accompanied by hail.
(2) Loo : These are strong, gusty, hot, dry winds blowing during the day over the north and north-western India.-Sometimes, they even continue until late in the evening . Direct exposure to these winds may even prove to be fatal.
Kaal Baisakhi is experienced in West Bengal and Loo in the north and north-western India.
(3) Mango showers : Towards the close of summer season, pre¬monsoon showers are common, especially in Kerala and Karnataka. They help in early ripening of mangoes. These are called as ‘mango shower’.

Question 5.
Where is Mawsynram located ? Why does Mawsynram receive the highest amount of rainfall ? (2012-1015)
Or
Why does Mawsynram receive the highest average rainfall in the world ? (2016-6RG3MN9; 2015-NH5M5AT)
Answer:
(1) Mawsynram is located in the southern ranges of the Khasi Hills at a height of 1500 m above the sea level. It receives the highest rainfall of the world.
(2) Mawsynram receives the highest amount of rainfall because :
(i) This place is enclosed by hills on three sides.
(ii) The relief features give this place funnel-shaped location.
(iii) The Bay of Bengal monsoon is trapped in these hills. These winds try to get out of it, but are forced to pour down there.

Question 6.
Distinguish between advancing monsoon and retreating monsoon. (2016-7LA1MBY; 2015-K0U3F83, 63UT30B; 2014-OESBI1W)
Answer:
Advancing Monsoon:
(1) Monsoon advances in the month of June and covers the country. in about a month.
(2) The low-pressure condition over the northern plains intensifies.
(3) The South-west Monsoon winds blow over the warm oceans therefore, bring abundant moisture to the sub-continent.
(4) These winds are strong and blow at an average velocity of 30 km per hour.
(5) The maximum rainfall of this season is receieved in the north-eastern part of the country.

Retreating Monsoon :
(1) Monsoon retreats during the months of October- November.
(2) The monsoon trough or the low-pressure trough over the northern plains is grádually replaced by a high-pressure system.
(3) The South-west Monsoon winds weaken and start withdrawing gradually.
(4) The low-pressure conditions over north-wèstern India, get transferred to the Bay of Bengal. This shift is associated with the occurence of cyclonic depressions.
(5) These cyclones cause heavy and widespread rain and are often very destructive.

Question 7.
How is monsoon known for its uncertainties ? Explain. (201 5-XXZU7VT)
Or
‘Indian Monsoon is highly unpredictable.’ Do you agree with the statement ? Give reasons in support of your answer. (2015-XWZRQPO)
Answer:
Monsoon wind is known for its uncertainties because :
(1) The movement of low-pressure trough controls the spatial distribution of rainfall.
(2) The alternation of wet and dry spells varies in intensity, frequency and duration.
(3) It sometimes, causes heavy floods in one part; it may be responsible for drought in the other.
(4) It is often irregular in its arrival and retreat.

Distribution Of Rainfall

3/5 Marks Question

Question 1.
Give any three reasons why do Rajasthan and parts of Gujarat receive scanty rainfall. (2014-L2MQUV2)
Or
Why do Rajasthan and parts of Gujarat receive scanty rainfall ? Give any three reasons. (2016-C66GL67; 2015-1AY5O59)
Answer:
(1) There is no barrier as such mountains which can stop the winds to give rainfall.
(2) The Aravalli hills in Rajasthan lie parallel to the South-west Monsoon winds. The hills do not possess much height.
(3) By the time South-west Monsoon winds reach upto Rajasthan after covering the vast northern plains, the winds become almost dry.

Monsoon As A Unifying Bond

3/5 Marks Questions

Question 1.
Explain the importance of monsoon rainfall in India. (2011-18/A1)
Or
Describe advantages of monsoon. (2016-6JJ4ZVP); (2015-1FQNRZN)
Answer:
India would have been an arid land or desert if there had been no phenomena of monsoons because :
(1) India receives 75% to 90% rainfall from monsoons.
(2) Himalayas do not allow the South-west Monsoons to cross over to Tibet. They deflect the monsoon winds towards the west over the Ganga plains where they provide rainfall.
(3) The triangular shape of Peninsular India divides the South-west Monsoons into two branches —Arabian Sea branch and Bay of Bengal branch.’
(4) In the first week of June, the Arabian Sea branch hits the Western coast and Bay of Bengal branch arrives in Assam. Both the branches merge over the north-western part of India.
(5) With the exception of the extreme north-west, the monsoon winds cover the country in about a month.

Question 2.
Study the data carefully and answer the following questions : Mumbai

(1) Which station has the higher range of temperature and why ?
(2) Which station receives the higher amount of rainfall ? Name the two most rainy months of this station.
(2011-12/BI)
Answer:
(1) Delhi has the higher range of temperature because it is located far away from the sea, so, its moderating influence decreases.
(2) Mumbai receives higher amount of rainfall. The two wost rainy months of this station are October and November.

Map Based Questions Identification

Question I.
Features by numbers are marked in the given political outline map of India. Identify these features with the help of following information and write their correct names on the lines marked in the map :
1. Meteorological Station of Jammu & Kashmir. [D.B. (M); 2012-1012, 1013, 1073, 48018, 48022; 2011-14/A1, 25/A1, 32/BI]
2. Meteorological Station of Kerala. [2012-1015, 48030, 48034; 2011-25/BI, 2016-9AGOTXP, CKGZ4NW, D29E40X, 2015-Imp.] Or, A Meteorological Station. [2015-MIP; 2014-FVQKQ6M, OESB11W, H6GINC1]
3. Meteorological Station of West Bengal. [2016-BU8Z65G; 2012-1016; 2011-11/BI, 13/BI, 06/Cl] Or, A Meteorological Station. [2015-MIP; 2014-03QSWGH, 91RZWON, TPXJ8CY]
4. Meteorological Station of Tamil Nadu. [2016-MDSOX5Z, 475IULX, C66GL67; 2015-IMP; 2012-1021, 48035, 48026, 2011-16/A1, 29/A1, 34/Al, 10/BI, 08/Cl] Or, A Meteorological Station. [2015-MIP1
5. Meteorological Station of Meghalaya. [D.B.(M); 2012-48024, 48039, 2011-06/A1, 2016-VYH1TDB, VXS6KC8, 1W84B6K, TKLP3FZ] Or, A Meteorological Station. [2015-3UWGAAX, HEUWPLZ; 2014-AN6K4SG, DELGOVM, OHFEKWR]
6. Meteorological Station of Maharashtra. [2016-O7OWHIF; 2012-48006, 48007, 48029, 2011-08/A1, 11/A1, 21/BI, 29/BI]
7. Meteorological Station of Rajasthan. [2016-MDSOX5Z, MK83TKT, 2014-J02KBXD; 2012-48032, 2011-06/BI] Or, A Meteorological Station. [2014-JO2KBXD]
A This topic is excluded from the latest syllabus (2019-20) of .C.B.S.E.
8. Meteorological Station of Karnataka. [2012-48023, 48031, 48036, 48038, 48040; 2011-18/Al, 21JA1]
9. Meteorological Station of Delhi. [2016-8BJGMDQ, Q62OXZI; 2012; 2011-12/Bu]

Answer:
1. Leh
2. Thiruvananthapuram
3. Kolkata
4. Chennal
5. Shillong
6. Nagpur
7. Jodhpur
8. Bengaluru
9. Delhi
This topic is excluded from the latest syllabus (2019-20) of CB.SE.

Question II.
On an outline map of India, show the following :
(i) Areas receiving rainfall over 400 cm.
(ii) Areas receiving less than 20 cm of rainfall.
(iii) The direction of the southwest monsoon over india.
Answer:

Locating And Labelling

Question III.
Locate and Label the following items on the outline map of India with appropriate symbols :
1. Areas receiving 0-20 cm rainfall. (2014-KVSAR) Or, Areas receiving less than 20 cm of rainfall. [2014-ZZ95-9800]
2. State receiving mango showers before pre-mansoon. [2014-KVSAR]
3. Place that receives highest annual rainfall in the world.