NCERT Class 9 Social Science Chapter 10 Climate

NCERT Class 9 Social Science Chapter 10 Climate Solutions to each chapter is provided in the list so that you can easily browse through different chapters NCERT Class 9 Social Science Chapter 10 Climate and select need one. NCERT Class 9 Social Science Chapter 10 Climate Question Answers Download PDF. NCERT SST Class 9 Solutions.

NCERT Class 9 Social Science Chapter 10 Climate

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Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. CBSE Class 9 Social Science Solutions are part of All Subject Solutions. Here we have given NCERT Class 9 Social Science Chapter 10 Climate and After, NCERT Class 9 Social Science Textbook of India and The Contemporary World – I: History, Contemporary India -I: Geography, Democratic Politics – I: Political Science, Economics and Disaster Management. for All Chapters, You can practice these here.

Climate

Chapter: 10

CONTEMPORARY INDIA – I (GEOGRAPHY) 

NCERT TEXTBOOK QUESTIONS WITH ANSWERS

Q. 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) Kal Baisakhi.

(b) Loo.

(c) Trade 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) South-west 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 characterizes 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.

Q. 2. (i) What are the controls affecting the climate of India?

Ans. The climate of India is affected by the following geographical factors: 

(i) Monsoon winds: India’s climate is controlled by monsoon winds. In summer, monsoons are on shore winds. These winds give most of rainfall to the country. In winter the monsoon winds blow from land to sea as N.E. Monsoons. These are dry winds.

(ii) Extent of the country: India is a vast country. The northern part lies in the temperate region and experiences hot summers and cool winters. The southern part lies nearer the equator and has hot season throughout the year.

(iii) Location of the Himalayas: The Himalayas act as a climatic barrier. This mountain wall protects India from the cold winds of Central Asia in winter. The Himalayas check the on-shore. S.W. Monsoons and force these to give rainfall.

(iv) The Indian Ocean: India lies at the head of the Indian Ocean. S.W. Monsoon originate from this ocean in summer and give rainfall over most of the country. Cyclones also originate over this ocean.

(v) The western disturbances: The western disturbances (cyclones) originate from the Mediterranean Sea and enter India in winter. These provide rainfall in north-west parts of India in winter.

(vi) Distance from the sea: The coastal areas experience maritime climate. These areas have equable climate. But the areas in the interior experience extreme or continental type of climate such as north-west India.

(vii) Relief of the land: Relief influences the distribution of temperature and rainfall in India. Mountainous areas have low temperatures. The windward slopes such as Western Ghats receive heavy rainfall while the leeward slopes (Deccan Plateau) lie in the rain-shadow and are dry.

(ii) Why does India have a monsoon type of climate?

Ans. India has a monsoon type of climate because:

(i) It is strongly governed by the monsoon winds.

(ii) Pre-monsoon, monsoon and post-monsoon duration is called here seasons.

(iii) India exists in the tropical area (viz. half of it is lying at south to the Tropic of Cancer between 20°N and 20°S).

(iv) Here are atmospheric conditions of pressure and surface winds, upper air circulation and western disturbances and tropical cyclones.

(v) Here is an active coriolis force, that deflects winds towards the right in the Northern Hemisphere and left in the Southern Hemisphere. 

(vi) Here acts the ENSO (El Nino Southern Oscillations). 

(iii) Which part of India does experience the highest diurnal range of temperature and why?

Ans. These are the north-western parts (Haryana, Punjab, U.P., Delhi etc.) of India. Here temperature rises upto 48° celsius. This is because: 

(i) Low pressure condition intensifies in north-western parts of India during May-June.

(ii) The south-west monsoon enters in peninsular India and it increases humidity in its north-western parts. 

(iii) Hot, dry winds namely Loo, starts blowing and dust storms spurt as south-westerly winds blow violently to compensate the low pressure condition formed in north-western parts of the country. 

(iv) Which winds account for rainfall along the Malabar coast?

Ans. Malabar coast falls in the Arabian Sea branch of monsoon or western trade winds that do heavy rainfall in Malabar. Collision of rain bearing clouds against elevated landforms of Western Ghats causes rain there (Malabar) during July month every year.

(v) What are Jet streams and how do they affect the climate of India? 

Or 

What are Jet streams and how do they affect the climate of India?

Ans. These are winds that blow above 12,000 metres over the troposphere. These are actually westerly winds blowing at higher altitude. Their velocity (speed) recorded in summer is about 110 km/h and about 184 km/h. in winter. These blow at the mid-latitude and over sub-tropical regions (north half of India).

These streams are located over 27°-30° north latitude. These create westerly disturbances. These disturbances are formed in the north and north-western parts (i.e., Punjab, Haryana, U.P., Delhi, Gujarat and Mumbai) of India. These are called the subtropical westerly jet streams. In summer, these move towards extreme north and therefore, replaced by an easterly jet stream called the tropical easterly jet. These do heavy rain over peninsular India consisting of coastal plains, Western and Eastern Ghats, Central Highland and Deccan plateau bloc.

(vi) Define monsoons. What do you understand by “break” in monsoon?

Ans. Monsoons are generally rain bearing and directing winds. This term has been derived from the Arabic word “mausim” first used by the Arab traders who used to come India for trading through sea routes. It means season. We therefore, can state them seasonal reversal of the wind system in monsoon.

‘Monsoon Break’ refers to the happening of wet and dry spells during the rainy season. Monsoon rains take place only for a few days at a time. They are interspersed with rainless intervals.

(vii) Why is the monsoon considered a unifying bond?

Ans. The term “unifying bond” implies an attachment or affection of something with another. Such conditions are formed when we talk of monsoon’s attachment with India. The cold winds from north side do not strike India as there exists a natural barrier of the Himalayas. In other places except India, are covered with the extreme cold wind in the same latitude. Similarly, the peninsular India is covered by the seas from three sides. This arrangement also ensures a moderate temperature in India. Again the seasonal reversal of the wind system provides a rhythmic cycle of seasons. India’s folk songs, lores, stories, manner of dress and diet etc., are added to the monsoon. Hence, we can state that monsoon in India acts as an unifying bond.

Q. 3. Why does the rainfall decrease from east to the west in Northern India?

Ans. This is because:

(i) The Bay of Bengal branch of monsoon is deflected after its reach at Assam and it therefore, do rain over the Ganga plains. 

(ii) The Arabian sea branch and the Bay of Bengal branch both do rain simultaneously in the western part of Northern India and not north India. 

(iii) Thus both the branches of monsoon are depleted water and the rain gradually decreases towards north side. For example, Rajasthan and parts of Gujarat receive scanty rainfall.

Q. 4. Give reasons as to why:

(i) Seasonal reversal of wind direction takes place over the Indian subcontinent.

Ans. The causes of wind reversal in Indian sub-continent are:

(a) Intensive heating during summer over northern plains causes the heat low around the Arabian sea.

(b) Monsoon trough is found at I.T.C.Z. normally positioned about 5°N of the equator. 

(c) Formation of high pressure area at 20°S over the Indian Ocean.

(d) Strong vertical air currents and high pressure formed due to immense heat over the Tibetan plateau. 

(e) Movement of the westerly jet to the north of the Himalayas and the tropical easterly jet over the Indian peninsula. 

(ii) The bulk of rainfall in India is concentrated over a few months. 

Ans. The bulk of rainfall in India is received during the four months of the rainy season i.e. June, July, August and September. This is the period of South-West Monsoons blowing from sea to land. These sea to land winds are the rain giver, as these moisture-laden winds are on-shore winds. The tropical cyclones add to the amount of rainfall. Easterly tropical jet stream, too, helps in the monsoonal rain during this period.

(iii) The Tamil Nadu coast receives winter rainfall. 

Ans. Konkan Coast faces on-shore S.W. Monsoons during summer. These moist laden winds give heavy rainfall (more than 300 cms). But these winds do not give much rainfall on the Coromandel Coast as it lies in the rain shadow of Western Ghats. Coromandel Coast also receives winter rainfall from N.E. Monsoons, but on Konkan Coast these winds are off-shore and do not give any rainfall. Thus Coromandel Coast gets rainfall in both the seasons, but the total amount is less than that of Konkan Coast. Total rainfall at Chennai is 128 cms, but it is 180 cms at Mumbai.

Tamil Nadu gets most of rain from North-East Monsoons in October and November. These winds after picking up moisture from Bay of Bengal give more rain on the east coast. Thus Tamil Nadu gets most of rain in winter when the fury of monsoons is over in most parts of the country. 

(iv) The delta region of the eastern coast is frequently struck by cyclones. 

Ans. Tropical cyclones are depressions originating over Bay of Bengal. These tropical cyclones are often very destructive. They cause heavy rains. These cyclones strike West Bengal and Bangladesh (Ganga Delta). These cross the eastern coast and affect the states of Orissa, Andhra Pradesh, Tamil Nadu and Kerala. The thickly populated deltas of Mahanadi, Godavari, Krishna and Kaveri are their targets.

(v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought prone.

Ans. The western part of Rajasthan in desert. It gets an annual rainfall less than 20 cms. This is due to the following reasons:

(i) Rajasthan is under the influence of S.W. summer monsoons. The Aravallis system lies parallel to the direction of S.W. monsoons coming from Arabian Sea. So these low mountain system is unable to check these winds. So western Rajasthan is practically dry. The southern parts get some rainfall.

(ii) This area lies at a great distance from the Bay of Bengal. The Bay of Bengal monsoons become dry and lose their moisture when they reach Rajasthan. 

(iii) This area is away from the Himalayan  region. So it does not come under the influence monsoons giving rain in the sub-Himalayan region. 

(iv) Gujarat has high variability of rainfall So it is a drought prone area. 

(v) The leeward slopes of Western Ghats remain in rain-shadow. 

Q. 5. Describe the regional variations in the climatic conditions of India with the help of suitable examples. 

Ans. In India, there are perceptible regional variations in climatic conditions within the country.

(a) In summer, the temperature may be 50°C or more in some parts of 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 – 45°C, while Thiruvananthapuram may have a temperature of + 20°C. 

(b) In certain places there is a wide differences between day and night temperatures. In the Thar desert, the day temperature may be 50°C  and drops down to near freezing point the same night. On the other hand, there is hardly any difference between day and night temperatures in the Andaman and Nicobar Islands or in Kerala. 

(c) While precipitation is mostly in the form of snowfall in the upper parts of Himalayas, it only rains over the rest of the country. 

(d) The annual precipitation varies from 400 cm in Meghalaya to less than 10 cm in Ladakh and Western Rajasthan.

(e) Most parts of the country receive rainfall from June to September, but Tamil Nadu coast receives rainfall during autumn and early winter. 

Q. 6. Discuss the mechanism of monsoons. 

Ans. To understand the mechanism of monsoons the following facts are important: 

(a) The difference in the rate of heating and cooling of land and sea on a large scale. During summers a low pressure area develops on the Indian landmass while the seas around experience comparatively high pressure.

(b) The shift of the position of the Inter-Tropical Convergence Zone. This is the equatorial trough normally positioned about 5°N of the equator, also known as the monsoon trough during the monsoon season.

(c) The presence of 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 monsoons. 

(d) The Tibetan high level plateau gets intensely heated during summers which results in strong vertical currents and formation of high pressure over the plateau at about 9 kilometers above sea level.

(e) The movement of the westerly jet to the north of the Himalayas and the presence of the Tropical easterly jet over the Indian peninsula during summers.

Apart from this, it has also been noticed that changes in the pressure conditions over the southern oceans also affect the monsoons. 

Q. 7. Give an account of weather conditions and characteristics of the cold season.

Ans. I. Weather Conditions: The temperature, atmospheric pressure, wind, humidity and precipitation usually determine the weather conditions at any point of time (a day or week) and the space. Weather is generally expressed as cool, hot, windy, calm, cloudy, bright, wet or dry. Actually, atmospheric conditions are called the weather. We experience hot weather in summer, cold weather in winters, wet weather in rainy season and cool and dry during October-November and the March and April respectively.

Weather phenomenon changes even in a day. We just feel suffocation due to humidity and scorching heat of July month. Suddenly clear sky is covered with clouds and it starts raining with lightning and strong wind. Something of such strange happens when cyclonic depression cause damages in deltas of the Mahanadi, Kaveri, Godavari and Krishna rivers. 

II. Characteristics of the Cold Season:

(i) It begins from mid-November in Northern India and pervades here till February. The mid-months, i.e., December and January are the coldest months.

(ii) The temperature gradually decreases during this period from south to the north. For example, in Chennai 20°-25°C while it is 10°- 15°C in northern plains.

(iii) Days are experienced warm while the nights are cold. Days are cut short while nights are longer. 

(iv) Most part of the country remains dry (i.e., without winter rain) during this period and only Tamil Nadu coast including Coromandel coast receive heavy winter rains.

(v) Coastal areas enjoy moderate temperature throughout the year while the rest of the country experiences cold, heat, humid and moderate according to the cycle of the seasonal change. It means, reversal of winds or monsoon type climate has more seasonal variations to experience. 

Q. 8. Give the characteristics and effects of the monsoon rainfall in India. 

Ans. I. Characteristics of the Monsoon Rainfall:

(i) It gives water in glut to the entire territories of India except some leeward sides, rain shadow regions and Thar etc., deserts.

(ii) Early in the season, the windward side of the Western Ghats receives heavy rainfall (i.e., more than 250 cm.). 

(iii) The rain shadow areas of Deccan Plateau and parts of Madhya Pradesh also receive scanty rains.

(iv) The maximum rainfall is recorded in the north-eastern part of the country. For example, the heaviest rainfall in Mawsynram.

(v) Indian monsoon takes “breaks” viz. interspersed with rainless intervals. This happens because of the monsoon trough, i.e.,determiner of the spatial distribution of rainfall. 

(vi) The frequency and intensity of tropical depressions also determine the amount and duration of monsoon rains.

(vi) The monsoon trough over the northern plains, becomes weaker causing the months of October-November, a period of transition from hot rainy season to dry winter conditions. 

II. Effects of the Monsoon Rainfall: 

(i) When the rains are heavy, the rivers get flooded causing heavy damage in the plains year after year.

(ii) A dry spell would cause as much misery as the river floods.

(iii) The characteristics of monsoon has a very destabilizing effect on Indian economy that continues to be predominantly agricultural and severely dependent on rainfed irrigation.

MAP SKILLS

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 south-west monsoon over India.

Ans.

PROJECT ACTIVITY

(i) Find out which songs, dances, festivals and special food preparations are associated with certain seasons in your region. Do they have some commonality with other regions of India?

Ans. A. Dances:

(i) Bharatnatyam: This dance has been able to retain the principles enunciated in Bharata’s Nitya Bhasha. It has survived in the  precincts of South Indian temples. It is a solo dance by women. It begins will Alarlpples (a prelude) followed by series of dance moods, rendered in varying style and tempo. Kerala, Tamil Nadu states are the regions where this cue is performed.

(ii) Manipuri: As the name itself implies, this dance is originated from Manipur state of India. Only movement of body and not codified gestures and expressions are incorporated with this dance. The dancer puts on a gorgeous dress covering her face with a neil and a skirt embedded with mirrors.

(iii) Kathakali: This dance is performed in Kerala state. A story is expressed through the gestures and expressions with this dance. It embodies in a high degree the principles laid down in the ancient Hindu scriptures of dance and drama.

(iv) Kathak: It is performed in north India (Delhi, Haryana, U.P., Rajasthan etc.). It was patronized by the rulers of the north Indian princely states during the British regime.

We can sum-up these dances in context to the states they performed as under:

Fig: Dances of India

These all dances are related to the agricultural operations.

B. Languages:

(i) Hindi: Throughout India barring some southern states.

(ii) Urdu: It is spoken in Muslim majority states. 

(iii) Bengali: It is spoken mostly in West Bengal and some parts of Orissa and Bihar.

(iv) Gujarati: In Gujarat state. 

(v) Marathi: In Maharashtra state.

(vi) Dravidian Languages: It is a group of Tamil, Telugu, Kannada and Malayalam spoken in the states of Tamil Nadu, Andhra Pradesh, Karnataka and Kerala.

C. Festivals:

Fig: Festivals of India

Note: Students are advised to ask their parents, teachers or read concerned literature on Indian folk lore and seasonal cuisines. Generally, every child knows what types of diets/ foods are prepared by his mother commensurating with the changing seasons. Similarly, there are songs like Chaiti, Malhar, Sravani, Barakha-Geet and Viraha etc. Thus, they may enhance their knowledge about the songs, cuisines, festivals and seasonal arts associated with the changing seasons particularly in their respective villages, districts and states.

(ii) Collect photographs of typical rural houses, and clothing of people from different regions of India. Examine whether they reflect any relationship with the climatic condition and relief of the area.

Ans. This question directly relates to the students’ self-doing for the sake of self-experience to be gained. Students should keep a diary for every session, i.e., year and enter in the same, the places they visit in company of parents and teachers. They should snap photos of people, landscapes, discuss on these topics with Sabhapati/Sarpanch of village and thus, obtain important information. At the end of session, they should write an article or mussing on the hill area, basins, plains etc. and make it interesting with proper illustrations of dress, including climate and its impact on the living conditions of the people so met during excursion, picnic, pilgrimage, tour etc. throughout the year.

FOR DOING IT YOUR SELF

1. Rearrange the ten stations in two different sequences:

(i) According to their distance from the equator.

Ans.

(ii) According to their altitude above mean sea-level. 

Ans.

3. (i) Name two rainiest stations. 

Ans. Shillong and Mumbai.

(ii) Name two driest stations.

Ans. Leh and Jodhpur. 

(iii) Two stations with most equable climate.

Ans. Thiruvananthapuram and Chennai. 

(iv) Two stations with most extreme climate.

Ans. Jodhpur and Delhi. 

(v) Two stations most influenced by the Arabian branch of southwest monsoons. 

Ans. Mumbai and Thiruvananthapuram.

(vi) Two stations most influenced by the Bay of Bengal branch of south-west monsoons.

Ans. Kolkata and Shillong.

(vii) Two stations influenced by both branches of the south-west monsoons.

Ans. Chennai and Nagpur.

(viii) Two stations influenced by retreating and north-east monsoons.

Ans. Chennai and Bengaluru.

(ix) Two stations receiving winter showers from the western disturbances.

Ans. Delhi and Leh.

(x) The two hottest stations in the month of:

(a) February.

(b) April.

(c) May. 

(d) June.

Ans. (a) February: Thiruvanantapura and Mumbai.

(b) April: Nagpur and Chennai.

(c) May: Nagpur and Jodhpur. 

(d) June: Nagpur and Delhi.

4. Now find out:

(i) Why are Thiruvanantapuram and Shillong rainier in June than in July?

Ans. Thiruvanantapuram receives the rainfall caused by S.W. monsoon winds instantly as it is located on proximity to Indian Ocean. Monsoon winds enter here on Ist June every year and it receives heavy rain. Shillong receives rainfall by virtue of the Bay of Bengal branch of the S.W. monsoon. As monsoon winds change their course in July, it receives less rain in that month.

(ii) Why is July rainier in Mumbai than in Thiruvananthapuram?

Ans. Mumbai falls in proximity to the Arabian Sea and monsoon winds starts blowing here in second week of the month of June. It receives rain subsequent to the nearby regions. The monsoon till then passes from Thiruvananthapuram to Andhra Pradesh and the regions onwards.

(iii) Why are southwest monsoons less rainy in Chennai?

Ans. Chennai falls in the rain shadow area of Eastern Ghats (i.e., at Coromandel Coast). Owing to this, this station receives scanty rain from the S.W. monsoon winds. 

(iv) Why is Shillong rainier than Kolkata?

Ans. Shillong receives rain from both branches of S.W. monsoon viz. Bay of Bengal and that of Arabian Sea branch. The Bay of Bengal branch collides against the high peaks of mountains here and do heavy rain. Kolkata, on the other hand, is deprived of rain by the Bay of Bengal branch of south-west monsoon hence, this station receives rain only from the Arabian Sea branch of S.W. monsoon.

(v) Why is Kolkata rainier in July than in June unlike Shillong which is rainier in June than in July? 

Ans. It is because Bay of Bengal branch of

south-west monsoon. Simultaneously rain in Kolkata in July with the Arabian branch of south-west monsoon while the Shillong get rain by the Bay of Bengal in July month that is one month earlier than Kolkata.

(vi) Why does Delhi receive more rain than Jodhpur?

Ans. Both branches of S.W. monsoon (viz. Bay of Bengal branch and Arabian Sea branch) collide against the high mountain peaks in Assam, Meghalaya and Tripura and pour there heavily. Their route is than diverted to the west and these pour water in the northern plains. Delhi also falls adjacent to northern plains. The Arabian Sea branch of monsoon also enters here. It comes with motion parallel to Aravallis, pours its water on Delhi and then moves towards Jammu and Kashmir through Chandigarh on its way. Jodhpur falls in Rajasthan where Aravalli give easy way to forward this branch of monsoon resulting in scanty or no rain in Jodhpur. It falls in rain shadow area where from clouds go but do not rain.

5. Now think why:

(i) Thiruvanantapuram has equable climate?

Ans. Equable climate generally is experienced in all stations falling nearer to the sea as the moisture does not allow high pressure to be formed any time here. This fact, also applies on Thiruvananthapuram and we see here equable climate throughout the year.

(ii) Chennai has more rains only after the fury of monsoon is over in most parts of the country? 

Ans. South-West Monsoon winds start retreating in September to October months. These are replaced by the North-East trade winds, i.e., winds blowing from extreme north-west of India. These winds receive vapor while moving over the Bay of Bengal to which they immediately carry to the Coromandel Coast in Tamil Nadu. These rain-bearing winds collide against Eastern Ghats and thus, Coromandal including Chennai receives heavy rain during winter season (viz. in November-December). 

(iii) Jodhpur has a hot desert type of climate?

Ans. Jodhpur falls in the rain shadow region and it is situated proxy to the Thar desert. This station has therefore, extreme climate and dusty as also hot winds namely “Loo” starts blowing here during summer. As the water-bearing winds pass over it without raining, this station remains arid throughout the year.

 (iv) Leh has moderate precipitation almost throughout the year? 

Ans. North-east trade winds blow throughout the year in Leh district of Jammu and Kashmir state. Monsoon winds never reach upto this altitude as they get lost their water completely. This station receives mostly snowfall because of its super altitude. Being it the coldest place, water- drops are freezed here. Thus, no rainfall or scanty precipitation we can only see here.

(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? 

Ans. Monsoon winds always prefer to blow over Thiruvananthapuram and Shillong irrespective of their distance from the sea. The winds blowing from Indian Ocean, Bay of Bengal and that of Arabian Sea simultaneously cover these stations during rainy season. Disturbances are caused over Andaman Sea and the Bay of Bengal as a result of the North-East trade winds usually fill the void created by the retreating monsoon during winter season. These winds while passing over above said sea; generally get vapor and do heavy rain in Shillong and Thiruvananthapuram. Thiruvanantapuram falls adjacent to the Arabian sea and Indian Ocean and Shillong is also nearer to Bay of Bengal and Andaman Sea. Delhi and Jodhpur are at larger distance from the sea coupled with nearer to the terrestrial region as also fall in sub-tropical belt. Hence, both these stations receive heavy rain during three months while these remain dry during the next nine months of the year. We can state in brief that quantum of rain here is affected due to different landforms, temperature, distance from the sea and mean altitude from the sea-level.

SOME OTHER IMPORTANT QUESTIONS FOR EXAMINATION 

MULTIPLE CHOICE QUESTIONS

Q. 1. Which of the following is not an element of weather and climate?

(a) Atmospheric pressure.

(b) Temperature.

(c) Humidity.

(d) Altitude.

Ans. (d) Altitude.

Q. 2. Which of the following terms refers to the sum total of weather conditions and variations over a large area for a long period of time (more than thirty years)?

(a) Atmosphere. 

(b) Annual range of temperature.

(c) Climate. 

(d) Monsoons.

Ans. (c) Climate.

Q. 3. Which of the following statements defines weather?

(a) Envelope of air surrounding earth.

(b) State of the atmosphere over an area at any point of time.

(c) Atmospheric conditions over a large area for a long period of time.

(d) Generalized monthly atmospheric conditions.

Ans. (b) State of the atmosphere over an area at any point of time. 

Q. 4. Which one of the following terms is used for the state of atmosphere over an area at any point of time?

(a) Weather. 

(b) Winds.

(c) Climate.

(d) Pressure.

Ans. (a) Weather.

Q. 5. In which of the following places of India precipitation is in form of snowfall?

(a) Shillong.

(b) Drass.

(c) Chandigarh.

(d) Haridwar.

Ans. (b) Drass.

Q. 6. Which of the following places of India experiences the highest summer temperature?

(a) Pahalgam.

(b) Leh.

(c) Thiruvananthapuram. 

(d) Jaisalmer.

Ans. (d) Jaisalmer.

Q. 7. Which of the following is the rainiest station?

(a) Shillong.

(b) Mumbai.

(c) Chennai. 

(d) Kolkata.

Ans. (a) Shillong.

Q. 8. Which one of the following is the driest station?

(a) Mumbai. 

(b) Leh.

(c) Bengaluru.

(d) Delhi.

Ans. (b) Leh

Q. 9. Most parts of India receive rainfall during which of the following months?

(a) December to February.

(b) March to May. 

(c) June to September. 

(d) October to November.

Ans. (c) June to September. 

Q. 10. In which of the following months does the Tamil Nadu coast get most of its rainfall?

(a) December to February.

(b) March to May. 

(c) June to September.

(d) October to November.

Ans. (d) October to November.

Q. 11. Which of the following places in India experiences a very high diurnal range of temperature?

(a) Kolkata. 

(b) Jodhpur.

(c) Chennai.

(d) Delhi.

Ans. (b) Jodhpur.

Q. 12. In which of the following places of India there is very little difference between day and night temperatures?

(a) Guwahati.

(b) Nagpur.

(c) Thiruvananthapuram.

(d) Delhi.

Ans. (c) Thiruvananthapuram.

Q. 13. In which of the following places are houses built on stilts?

(a) Assam.

(b) Rajasthan.

(c) Goa.

(d) Kerala.

Ans. (a) Assam.

Q. 14. Which one of the following is not one of the six major controls of the climate of any place? 

(a) Latitude.

(b) Temperature.

(c) Pressure and wind system. 

(d) Distance from the sea. 

Ans. (b) Temperature.

Q. 15. Latitude and altitude of a place determine which of the following climatic elements of a place?

(a) Pressure and wind system. 

(b) Temperature. 

(c) Rainfall pattern. 

(d) All the above.

Ans. (d) All the above. 

Q. 16. Which of the following places have cooler climate even during summers? 

(a) Allahabad. 

(b) Mumbai. 

(c) Mussoorie.

(d) Amritsar.

Ans. (c) Mussoorie.

Q. 17. Which of the following places of India experiences extreme type of climate?

(a) Shillong. 

(b) Bengaluru. 

(c) Chennai.

(d) Delhi.

Ans. (d) Delhi. 

Q. 18. Due to which of the following factors does Pune receive much lesser rainfall as compared to Mumbai?

(a) It is located on the leeward side of Western Ghats. 

(b) It is located on windward side of Western Ghats.

(c) Continentality.

(d) Distance from the sea.

Ans. (a) It is located on the leeward side of Western Ghats.

Q. 19. Which of the following latitudes passes through the middle of our country, giving it the characteristics of tropical as well as subtropical climate?

(a) Tropic of Capricorn. 

(b) Tropic of Cancer.

(c) Equator.

(d) 82°30′N.

Ans. (b) Tropic of Cancer.

Q. 20. The Indian subcontinent experiences comparatively milder winters as compared to Central Asia due to which of the following factors? 

(a) The Tropic of Cancer. 

(b) The surrounding seas.

(c) The Himalayas.

(d) Ocean currents. 

Ans. (c) The Himalayas.

Q. 21. Which of the following atmospheric conditions govern the climate and associated weather conditions in India?

(a) Pressure and surface winds. 

(b) Upper air circulation.

(c) Western cyclonic disturbances and tropical cyclones. 

(d) All the above.

Ans. (d) All the above.

Q. 22. Which of the following winds brings widespread rainfall over the mainland of India?

(a) Northeasterly.

(b) Westerlies.

(c) Southwest monsoon winds.

(d) Sea breeze.

Ans. (c) Southwest monsoon winds.

Q. 23. Which of the following is a component of upper air circulation? 

(a) North-easterlies. 

(b) Jet stream.

(c) South-west monsoon.

(d) Kal Baisakhi. 

Ans. (b) Jet stream.

Q. 24. From which of the following Pressure belts do the north-easterly trade winds originate?

(a) Equatorial low pressure belt.

(b) Subtropical high pressure belt of the Northern Hemisphere.

(c) Subtropical high pressure belt of the Southern Hemisphere. 

(d) Temperate low pressure belt of the Northern Hemisphere.

Ans. (b) Subtropical high pressure belt of the Northern Hemisphere.

Q. 25. Due to which of the following reasons is the southwest monsoons rain bearing winds?

(a) They blow from low pressure area of north-eastern India towards the seas.

(b) They are seasonal winds.

(c) They blow over warm Indian Ocean and gather moisture.

(d) They strike the Himalayas. 

Ans. (c) They blow over warm Indian Ocean and gather moisture. 

Q. 26. Which of the following prevents the southwest monsoon winds escaping from India?

(a) The surrounding seas. 

(b) The Himalayas.

(c) Low pressure over Central Asia.

(d) The Indian deserts. 

Ans. (b) The Himalayas.

Q. 27. The word monsoon is derived from a word which literally means which of the following?

(a) Seasons.

(b) Wind pattern.

(c) Change.

(d) Mosambi.

Ans. (a) Seasons.

Q. 28. In which of the following stations of India’s mainland do the monsoons arrive first?

(a) Thiruvananthapuram. 

(b) Kolkata. 

(c) Chennai.

(d) Delhi.

Ans. (a) Thiruvananthapuram. 

Q. 29. By which of the following dates do southern parts of our islands receive their first monsoon showers? 

(a) First week of April. 

(b) First week of May.

(c) First week of June. 

(d) Mid-October. 

Ans. (a) First week of April.

Q. 30. Which of the following stations of India experiences snowfall in winter? 

(a) Aurangabad.

(b) Guwahati.

(c) Ooty.

(d) Srinagar.

Ans. (d) Srinagar.

Q. 31. Which of the following causes rainfall in West Bengal during the hot weather season?

(a) Mango showers.

(b) Kal Baisakhi.

(c) Southwest monsoon. 

(d) Retreating Monsoon. 

Ans. (b) Kal Baisakhi.

Q. 32. In which month the transition season changes the hot rainy season to dry winter season?

(a) December to February. 

(b) February to March.

(c) June to July. 

(d) October to November.

Ans. (d) October to November.

Q. 33. The term monsoon is originated from?

(a) German. 

(b) Hindi.

(c) Latin.

(d) Arabic.

Ans. (d) Arabic.

Q. 34. Kal Baisakhi is associated with:

(a) Punjab.

(b) Kashmir.

(c) Karnataka. 

(d) Bengal.

Ans. (d) Bengal.

Q. 35. The peninsular part of India experiences peak summers earlier than northern India because: 

(a) there is less rainfall in the peninsula during that time. 

(b) cold waves from Central Asia sweeps through the northern plains during the time.

(c) due to northward movement of the sun, the global heat belt shifts northward. 

(d) clouds do not form in those months.

Ans. (c) due to northward movement of the sun, the global heat belt shifts northward.

Q. 36. Bengal, Orissa and Andhra Pradesh coasts are frequented by cyclones because: 

(a) the level coastline makes the cyclones penetrate these areas earlier.

(b) these areas are close to a volcano.

(c) low pressure conditions in northwest India lead to the creation of depression over Andaman Sea. 

(d) heavy rainfall in these parts encourage strong wind conditions. 

Ans. (c) low pressure conditions in northwest India lead to the creation of depression over Andaman Sea.

Q. 37. Mango showers occur in which one of the following group of two states?

(a) Bihar and West Bengal. 

(b) Tamil Nadu and Andhra Pradesh.

(c) Karnataka and Kerala.

(d) Maharashtra and Andhra Pradesh. 

Ans. (c) Karnataka and Kerala.

Q. 38. Which is the coldest place in India? 

(a) Drass.

(b) Srinagar.

(c) Shillong.

(d) Bikaner.

Ans. (a) Drass. 

Q. 39. Which area is not an area of low precipitation?

(a) Western Rajasthan and Gujarat.

(b) Leh in Jammu and Kashmir.

(c) Deccan plateau.

(d) Assam.

Ans. (d) Assam. 

Q. 40. In winter the western cyclo disturbances originate from which sea? 

(a) Mediterranean Sea. 

(b) Indian Ocean.

(c) Caspian Sea.

(d) Arabian Sea. 

Ans. (a) Mediterranean Sea.

Q. 41. Which one of the following states suffers from loo? 

(a) Tamil Nadu.

(b) Uttar Pradesh.

(c) Gujarat. 

(d) None of these.

Ans. (c) Gujarat.

Q. 42. In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option. 

Assertion (A): India’s climate has characteristics of tropical as well as subtropical climates.

Reason (R): Almost half of the country, lying south of the Tropic of Cancer, belongs to the tropical area. All the remaining area, north of the Tropic, lies in the sub-tropics.

Options: 

(a) (A) is correct but (R) is wrong.

(b) (A) is wrong but (R) is correct. 

(c) Both (A) and (R) are true but (R) is not the correct explanation of (A). 

(d) Both (A) and (R) are true and (R) is the correct explanation of (A). 

Ans. (d) Both (A) and (R) are true and (R) the correct explanation of (A).

Q. 43. In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option.

Assertion (A): The amount of solar energy received does not vary according to latitude.

Reason (R): It is because of the plain land surface of the earth.

Options:

(a) (A) is wrong but (R) is correct. 

(b) (A) is correct but (R) is wrong. 

(c) Both (A) and (R) are wrong.

(d) Both (A) and (R) are true but (R) is no the correct explanation of (A).

Ans. (c) Both (A) and (R) are wrong. 

Q. 44. In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option. 

Assertion (A): India should have been an arid land.

Reason (R): North easterly winds carry little moisture as they originate and blow over land. 

Options: 

(a) (A) is correct but (R) is wrong.

(b) (A) is wrong but (R) is correct. 

(c) Both (A) and (R) are true and (R) is the correct explanation of (A).

(d) Both (A) and (R) are true but (R) is not the correct explanation of (A). 

Ans. (c) Both (A) and (R) are true and (R) is the correct explanation of (A).

Q. 45. In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option.

Assertion (A): The Monsoon, unlike the trades, are steady winds and are but are regular in nature. 

Reason (R): These are affected by different atmospheric conditions encountered by it, on its way over the warm tropical seas.

Options:

(a) (A) is correct but (R) is wrong.

(b) (A) is wrong but (R) is correct.

(c) Both (A) and (R) are true and (R) is the correct explanation of (A).

(d) Both (A) and (R) are true but (R) is not the correct explanation of (A).

Ans. (b) (A) is wrong but (R) is correct.

Fill in the Blanks:

(i) An atmosphere experienced at any point of time and space is known as _________.

Ans. Weather.

(ii) India’s climate is controlled by __________.

Ans. Monsoon winds.

(iii) Hot and dry winds are known as __________.

Ans. Loo.

(iv) The western part of Rajasthan is _________.

Ans. Desert.

(v) __________ receives the heaviest rainfall in the world.

Ans. Mawsynram.

True and False:

(i) Atmospheric Pressure denotes pressure of winds.

Ans. True.

(ii) May and June are the rainiest months of India.

Ans. False.

(iii) October and November are the rainiest months in the coastal districts of Tamil Nadu.

Ans. True.

(iv) Jodhpur in Rajasthan is the driest place in India.

Ans. True.

(v) Mumbai has an extreme type of climate. 

Ans. False.

VERY SHORT ANSWER TYPE QUESTIONS

Q. 1. What is climate?

Ans. The climate refers to the sum total of weather conditions and variations over a large area for a long period of time.

Q. 2. What is weather?

Ans. ‘Weather’ refers to the state of the atmosphere over an area at any point of time.

Q. 3. What is the climate of India?

Ans. India’s climate is described as “Tropical Monsoon Type of Climate”.

Q. 4. What does ‘monsoon’ imply?

Ans. The word, ‘monsoon’ comes from the Arabic word ‘mausim’ which means season. It implies a seasonal reversal in the wind direction throughout the year.

Q. 5. Name the two branches of the monsoon.

Ans. The two branches of the monsoon are:- The Arabian Sea branch and the Bay of Bengal branch.

Q. 6. What is burst of monsoon?

Ans. Around the time of its arrival, the normal rainfall increases suddenly and continues constantly for several days. This is known as the ‘burst of the monsoon.

Q. 7. What is the meaning of ‘retreating monsoons’?

Ans. During the months of October and November, the temperature in the Northern plains begins to decrease, and because of low temperature, the pressure starts rising and the low pressure is no longer strong enough to attract the monsoon winds. This results in the retreat of the monsoon.

Q. 8. ‘The peninsular region does not have a well defined cold season.’ Give reason.

Ans. Due to the moderating influence of the sea, the peninsular region does not have a well defined cold season.

Q. 9. State two chief characteristics of the Western Disturbances.

Ans. These originate over the east Mediterranean Sea and these cause rain in North India.

Q. 10. What is El Nino?

Ans. It is Spanish word which means the child. It is the name of warm water current that flows past the Peruvian Coast.

Q. 11. What is an Equable Climate’? Give example.

Ans. It is a climate which is neither too hot in summer nor too old in winter. The coastal regions, influenced by the cool sea breeze are known for their equable or moderate climate. Hence the climate of coastal regions is known as Equable Climate. 

Q. 12. What is ‘Extreme Climate’? Give examples. 

Ans. The climate in which the summer is extremely hot and winter is too cold, is known as extreme climate. It is also known as Continentality. This type of climate is found in the arid regions of Rajasthan, South-west Punjab. It increases with increase in distance of a place from sea. 

Q. 13. What does the term continentality mean?

Ans. 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. 14. What is ‘Rain Shadow’?

Ans. That side of the mountain which does not get much rain is known as rain shadow.

Q. 15. What are the elements of weather and climate?

Ans. The basic elements of both weather and climate are same, viz. -Temperature, Humidity, Rainfall, Pressure, Winds and Cloudiness or Sunshine. 

Q. 16. Why do the coastal areas of India experience less contrast in temperature? 

Ans. The coastal areas experience less contrast in temperature because of the influence of the sea, e.g., Mumbai experiences an equable climate.

Q. 17. Why is there decrease in rainfall from east to west in the Northern Plains? 

Ans. There is 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. 18. Why does the amount of solar radiation vary with latitude? 

Ans. 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. 19. How does the temperature decrease with altitude? 

Ans. The temperature of 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 summers. 

Q. 20. Which two factors affect the wind and pressure system of an area and how? 

Ans. The latitude and the altitude of the place affect the temperature and rainfall of the area.

Q. 21. What are ocean currents? Name the two types.

Ans. 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. 22. How does the relief of an area affect the climate of a place? 

Ans. 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. 23. Which parallel of latitude passes through the center of India?

Ans. The parallel of latitude is the Tropic of Cancer, 231/2° N. 

Q. 24. What is the influence of the division of India by the Tropic of Cancer?

Ans. The Tropic of Cancer divides India into the Tropical zone which lies to the south and the subtropical area which lies to the north. It gives India’s climate a tropical and a sub-tropical character

Q. 25. What is Coriolis Force? 

Ans. It is an apparent force caused by the earth’s rotation. It 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. 26. What do you know about South-Western Monsoon Winds?

Ans. 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 pressure area over the Indian subcontinent. This is known as south western monsoon.

Q. 27. 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 cause the monsoon winds to deflect towards the west over the Ganga Plains.

Q. 28. 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 cause rainfall in West Bengal. 

Q. 29. What is the ITCZ?

Ans. The Inter Tropical Convergence Zone is a low pressure trough lying 5° North and South of the Equator. The North-East and the South-East Trade winds meet here. It moves north or south of the Equator with the apparent movement of the sun.

Q. 30. How is the intensity of the monsoon predicted?

Ans. The difference in pressure over Tahiti (Pacific Ocean, 18°C/149° W) and Darwin in Northern Australia (Indian Ocean, 12°30’S/131°E) is computed to predict the intensity of the monsoons. If the pressure differences were negatives, it would mean below average and late monsoons.

Q. 31. What are Jet Streams? 

Ans. These are fast blowing westerly winds that blow in a narrow zone in high altitudes of above 1200 meter in the troposphere. A number of separate Jet streams have been identified with their speeds varying from 110 km/hr to 184 km/hr.

Q. 32. What is loo?

Ans. These are strong, gusty, hot, dry winds blowing during a day over the North and North-Western India. Direct exposure to these winds may even prove to be fatal

Q. 33. What does ‘Kaal Baisakh’ refer to? 

Ans. During the months of April and May the localized thunderstorms associated with violent winds, torrential rains often accompanied by hail are known as the Kaal Baisakhi. This term is more popular in West Bengal.

Q. 34. What are ‘Mango Showers’?

Ans. Towards the close of the summer season, pre-monsoon showers are common especially, in Kerala and Karnataka. They help in early ripening of mangoes, and are often referred to “mango showers”.

Q. 35. What does the term ‘Mahawat’ mean?

Ans. The total amount of rainfall over Northern plains during winter is locally known as ‘Mahawat’. It is important for the cultivation of the Rabi crops.

SHORT ANSWER TYPE QUESTIONS

Q. 1. Why are South West Monsoons less rainy in Chennai?

Ans. The Arabian Sea branch of S.W. Monsoons strike, first of all, against Western Ghats. After crossing Western Ghats, these winds descend down the leeward slope of Western Ghats and do not give much rain there. The Karnataka and Tamil nadu remain in rain shadow. Low Eastern Ghats also do not check these winds. So these winds give less rainfall in Chennai. S.W. monsoons give 35 cms of rainfall in June-September period, but N.E. monsoons give 85 cms of rainfall in winter.

Q. 2. Mention the features of hot weather season in India.

Ans. (i) From March to May, it is hot weather season in India. The summer months experience rising temperature and falling air pressure in the northern part of the country. In peninsular India, temperatures remain lower due to the moderating influence of the ocean.

(ii) A striking feature of this season is ‘loo’ which is a strong, gusty hot and dry wind blowing during the day over the north and north-western India. It is called ‘Kal Baisakhi’ in West Bengal.

(iii) Towards the close of this season, pre-monsoon showers are common in Kerala and Karnataka These are called ‘ mango showers’.

Q. 3. Distinguish between equable and extreme climates. 

Ans.

Q. 4. Distinguish between Rainfall and Precipitation. 

Ans.

Q. 5. Distinguish between Weather and Climate.

Ans.

Q. 6. Distinguish between Windward side and Leeward side. 

Ans.

Q. 7. What are the Monsoons? Describe briefly the Summer Monsoons.

Ans. Monsoons: The word monsoon is derived from the Arabic word ‘mausim’ which means season. These monsoon winds are seasonal winds. The term was first used for the monsoon winds blowing over the Arabian Sea. In this wind system there is a reversal of wind direction according to seasons. In summer, monsoons blow from sea to land and in winter monsoons blow from land to sea.

The Summer Monsoons: During the months of May and June rays of the sun are vertical on the Tropic of Cancer. So it is very hot in the northern plains of India. The air is heated, gets lighter and starts moving upward. All this results in the low pressure area in north-western India but the atmospheric pressure is comparatively high over the Indian Ocean. the wind always move from an area of high pressure towards an area of low pressure. Therefore, the winds begin to blow from the Indian Ocean towards the northern plains of India. These winds enter India from two different directions.

1. Bay of Bengal branch.

2. The Arabian Sea branch.

1. Bay of Bengal branch of the Monsoons: The Bay of Bengal Monsoons enter from two different directions.

One of its branches passes through Bangladesh and reaches Meghalaya where these strike against the Khasi, Garo and Jaintia hills, more upward and cause heavy rainfall. Mawsyaram here receives the heaviest rainfall the world

2. The Arabian Sea branch of Monsoons: The Arabian Sea branch enter India from three directions:

Its main branch strikes against the Western Ghats. As they are moisture laden they cause heavy rain on the western coast and the western slopes of the Western Ghats. After crossing the Western Ghats they become devoid of moisture.

Q. 8. Explain any three factors which affect the mechanism of monsoons.

Ans. The following three factors affect the mechanism of monsoons: 

(a) The difference in the rate of heating and cooling of land and sea on a large scale. During summers a low pressure area develops on the Indian landmass while the seas around experience  comparatively high pressure. 

(b) The shift of the position of the Inter-Tropical Convergence Zone. This is the equatorial trough normally positioned about 5°N of the equator, also known as the monsoon trough during the monsoon season.

(c) The presence of high pressure area, east of Malaga Car approximately at 20°S over the Indian Ocean. The intensity and position of this pressure area affects the Indian monsoons.

Q. 9. Explain the influence of the Himalayas on India’s climate.

Or

“The presence of the Himalayas in the north is of great significance in determining form and amount of precipitation over Indian subcontinent.” Describe the statement. 

Ans. The Himalayas and their extensions provide a shield to the northern frontier of the country. It influences India’s climate in a number of ways:

(a) The Himalayas have provided India with a compact physical setting.

(b) They act as an effective climatic divider. 

(c) They protect the sub-continent from the northern winds, These cold and chilly winds originate near the Arctic Circle and blow across Central and Eastern Asia. 

(d) The mountain wall blocks the monsoon winds and cause them to shed bulk of their moisture in India.

(e) The mountain wall gives the whole of northern India a touch of tropical climate, hot and wet summers and dry winters. 

Q. 10. Why is it so that temperature in Rajasthan soars so high during summer compared to Thiruvananthapuram?

Ans. Rajasthan is situated proxy to the thar desert. Thus it has extremely hot climate and dusty hat winds blows there during summer. On other hand Thiruvantanpuram situated near the sea coast or coastal area. Thus it experience equable climate while Rajasthan is far away from sea coast. In thiruvananthapuram equable climate generally experienced in all station felling nearer to the sea as the moisture does not allow high pressure to be formed any time here. This fact also applies on Thiruvananthapuram and see here equable climate throughout year. 

Q. 11. Rainfall decreases as one travels up the Ganges Valley. Why?

Ans. A branch of summer monsoon from Bay of Bengal moves up the Ganges Valley. It moves westwards along the Himalayas. The lower Ganges Valley receives the rainfall first, and the upper Ganges Valley later on. Kolkata has an annual rainfall of 162 cms. As the branch of monsoons moves westward. It gets drier and drier. So it gives less rainfall. Patna gets 102 cms of rainfall, Allahabad 91 cms, Delhi gets 56 ema of rainfall.

Q. 12. Discuss the factors controlling the Indian climatic conditions. 

Ans. The factors controlling the Indian Climate:

(i) Relief Features: The Himalayas at the norms act as a great barrier and save India from the cold winds of Central Asia. The Himalayas also act as a barrier to monsoon winds and force them lose all their moisture in this country. Western Ghats and Khasi hills in Meghalaya lie right across the path of the monsoon winds and so get heavy rainfall.

(ii) Location: The country extends from 6°N to 37°N. latitudes. The Indian peninsula is surrounded by the Arabian Sea, the Indian Ocean and the Bay of Bengal. They give heavy moisture to monsoon winds which in turn give heavy rain to India.

The climate of India is also influenced by the climatic conditions over rest of Asia. This is the reason, north-western India receives rain from Mediterranean sea in winter. The desert of Rajasthan is a continuation of deserts of south-west Asia.

(iii) Monsoon: The monsoon winds dominate the climate of India. There is a seasonal reversal of winds almost throughout the country.

(iv) The Seasons: There are four seasons in India: 

(a) The Cold Weather Season (December to February). 

(b) The Hot Weather Season (March to May). 

(c) The South-West Monsoon (June to September). and 

(d) The Transition Season or Retreating Monsoon Season (October- November).

Q. 13. What is a Rain Shadow?

Ans. Rain Shadow: That side of the mountain which does not get much rain is known as the rain-shadow. The winds after crossing the summits of the mountains descend along the slopes on the other side of the mountain which are too high as in the case with the Himalayas which render Tibet a dry region. The dry side of the monsoon is called the leeward side and the rainless area on the leeward side is called the rain-shadow. That side of the mountain where moisture laden winds strike and bring rain is called the windward side. When the moisture laden winds blow at right angle to the mountain ranges, we can observe these windward and leeward sides obviously.

Q. 14. Why does Thiruvananthapuram receive equable climate? 

Ans. This is because:

(i) Thiruvananthapuram (the capital city of Kerala) is free from the hot climate of the temperate zone because of its location on hill side. We already know that the temperature recedes with the higher altitude of the land from the sea level.

(ii) This capital city is in vicinity to the Arabian sea which maintains here, the moderate temperature throughout the year.

Q. 15. Discuss the reasons for uneven distribution of rainfall in India. 

Ans. Reasons for uneven distribution of rainfall in India:

(i) Heavy rainfall is recorded in hill and forest areas because of altitude and dense forests which make the atmosphere cool and force the rain drops fall. For example, Assam, the Ganga Delta, the Western Ghats, the Western Coastal regions.

(ii) Areas without elevated mountains only receive scanty rainfall because of their failure to strike against rain bearing clouds (winds) of the monsoon seasons. For example, Scanty rainfall in Rajasthan due to Aravalli range of mountains.

(iii) Areas falling in the rain shadow and leeward sides receive sparse rainfall. For example, Eastern side of the Western Ghats or Ladakh.

(iv) Areas falling first in the way of the rain bearing winds receive more rainfall as compared to the areas falling the last. For example, Kolkata falls first in the way of Bay of Bengal branch of monsoon therefore, it receives more rainfalls than Allahabad or Delhi.

Q. 16. What is a Jet Stream?

Ans. It is a fast blowing air current in a narrow zone of upper troposphere. Jet stream is a part of upper air circulation which is oft types: 

(i) A westerly jet stream that blows in the winter season in south of the Himalayas. 

(ii) A easterly jet stream blows at about 25°N in the troposphere. It brings sudden outbreak of monsoons in northern India.

Q. 17. ‘Mawsynram receives the highest amount of rainfall in the world.’ Why? 

Ans. Mawsynram is the rainiest place of the world with an average annual rainfall of 1140 cms. It is located on the southern slopes of Khasi Hills (Meghalaya) at a height of 1500 metres above sea level. This place is enclosed by hills on three sides. The relief features give this place a funnel shaped location. The Bay of Bengal branch of monsoons is trapped in these hills. These winds try to get out of it. These are forced to rise again and again resulting heavy rainfall. 

Q. 18. Punjab and Haryana also receive rain in winter. Why? 

Ans. Western disturbances are low pressure systems which originate in West Asia and the regions near Mediterranean Sea. These travel eastwards across Iran and Pakistan and reach India during the winter season. These are active in winter in northern India. On an average, four or five such depressions visit India each month. These give rainfall in areas of Jammu and Kashmir, Punjab, Himachal Pradesh, Haryana and Rajasthan. The amount of rainfall decreases towards the east. This rainfall (20 mm-50 mm) is useful for rabi crops especially wheat. In colder parts of Himachal Pradesh and Jammu and Kashmir, these cyclones provide snowfall.

Q. 19. Why does the rainfall gets on decrease as we go up the Ganga Valley but increase as we go up the Indus Valley?

Ans. We know that the monsoons in summer rise from Bay of Bengal and Arabian Sea simultaneously. The Bay of Bengal branch causes heavy rainfall in the Brahmaputra valley and Assam hills. The rain bearing winds strike at the lofty peaks of the Himalayas there and deflected towards the west. Thus, they move up the Ganga Valley but as they proceed westwards, they become drier and cause less rain with every steps towards the west of the plains. Owing to this decreasing trend, Kolkata receives 162 cms, Patna 105 cms., Allahabad 76 cms and Delhi 56 cms. rainfall. Distance from the sea also decreases the quantum of the rainfall in the areas proportionately. Places near the sea get more rainfall as compared to the places lying far away from the sea. As we move away from the Bay of Bengal to Punjab, the distance from the sea also become more and more leading less and lesser of rain.

Another branch of the monsoon, i.e., south-east monsoon blow from the Arabian sea. It enters in India and blows over Rajasthan but the Aravalli Hills there cannot check them and so, these winds pass on without raining there. At their access to Himachal Pradesh, these monsoon winds strike with the lofty peaks of Himalayas and cause heavy rain there. The Bay of Bengal branch also joins here and thus, the rain goes on increasing as we go up the Indus Valley.

Q. 20. Explain why the deltas of Peninsular rivers are frequently struck by cyclones.

Ans. It occurs in the months of October and November viz. during retreating monsoon season. This is a period of transition from hot rainy season to dry winter season with the apparent movement of sun towards south. In the second half of October, the temperature begins to fall at a rapid speed, especially in the northern India. The low pressure conditions are gradually converted to high pressure conditions. Low pressure conditions then start forming over the Bay of Bengal by November. This shift cause cyclonic depression over the Andaman sea.

These tropical cyclones cause heavy and widespread rains on the eastern coast of India. So often they become destructive and the densely populated fertile deltas of the peninsular rivers (i.e., Krishna, Kaveri, Godavari and Mahanadi) are frequently struck by these cyclones. They cause irreparable damage to life and property there.

Q. 21.

Study the table given above and answer the following questions:

(a) What type of climate does station A have and why?

Ans. Station A has humid type of climate. Because temperature decreases with hight and the amount of coldness in air gets increased.

(b) What type of climate does station B and why?

Ans. The station B has dry climate because, the height of this place is comparatively less.

Q. 22. What recent advances have been made in the knowledge about climate?

Ans. Meteorological data have been recently collected from stations on land, ships in the oceans and from upper air with the help of balloons. These are studied at the global level. It is now processed shortly with the help of supercomputers. Weather satellites now send the photographs of cloud cover every hour which we watch on TV daily. In earlier times, these data were collected only at the regional level.

Q. 23. What is Kal Baisakhi?

 Ans. Violent black clouds gather in the sky in the month of Baisakh (April) and this cloudy weather is called Kal Baisakhi. This name is given to the north-westerly and northerly killer winds in Bengal and Assam. These cause violent showers. These are essentially occur in evening with thunder storms. Occasionally, local tornado or storms also develop in this weather condition.

Q. 24. Describe the role of Elnino and Southern  Oscillation to control the climate of India?

Ans. The Changes in the pressure condition over the southern oceans also affect the monsoons. Normally when the tropical eastern south pacific ocean experiences high pressure, the tropical eastern Indian ocean experiences low pressure this periodic change in pressure conditions is known as the southern oscillation or so. The difference in pressure over pacific ocean and the Indian ocean is computed to predict the intensity of the monsoons. If the pressure differences were negative, it would mean below average and late monsoons.

Besides, A feature connected with the so is the El Nino that is a warm current and follows past the peruvian coast. The changes in pressure conditions are connected to the EI Nino. Hence, this phenomenon is referred to as El Nino southern Oscillations.

Q. 25. Why is Shillong rainier than Kolkata?

Ans. Shillong receives an annual rainfall of 225 cms while Kolkata gets an annual rainfall of 162 ems. The Bay of Bengal branch of monsoon causes rainfall in these areas. One branch of monsoon moves up the Brahmaputra Valley, the topographical location (hills of Meghalaya).

Kolkata lies in plain land hence the monsoon winds blowing from the Bay of Bengal let them sky without pouring and these are the peaks of Himalayas on Meghalaya that blew hard them and they start pouring tears (rain-drops) on the surface of the earth.

Q. 26. Explain why north-west India receive rainfall in winter.

Ans. North-west India receives rainfall in winter due to cyclonic depressions or western disturbances. As a result of these depressions, these are light rains in the gangetic plains or the plains of the Punjab and Haryana. At the same time, Himachal Pradesh and Jammu and Kashmir receive heavy rainfall. This is because these cyclones enter in India from the western side to the eastern region. Thus, their direction is from west to east. These cyclones rise from far-off western areas, i.e, over Persian Gulf and the Mediterranean sea. They fly with great velocity over the Arab countries, Iran and Pakistan and give light rainfall in Punjab and Haryana. These winds convert into snow when reach over Himachal Pradesh and Jammu and Kashmir hence, there occur snowfall. These winter rains though light in quantum, prove beneficial for the wheat crop which is grown in winter (Rabi season) in Punjab and Haryana plains.

Q. 27. Explain why does Chennai receive more rainfalls in winter than in summer. 

Ans. Chennai is the capital city of the state of Tamil Nadu. It lies on the Coromandel coast on the eastern coastal plain. This region generally receives rainfall in winters and also in summers. However, quantum of winter rainfall is always recorded larger than it is in summer. This part of the land lies at rain shadow of Western Ghats therefore, does not receive much rainfall during south-west monsoon season i.e. in summer. The south-west monsoon is replaced by the north-east trade winds and they pick-up moisture while crossing the Bay of Bengal. These retreating monsoon winds therefore, become rain fetching winds specially for Chennai in Coromandel coast.

Q. 28. What do you understand by the term ‘Loo’?

Ans. ‘Loo’ is a local wind. It is a very hot and dry wind which blows during the day time in northern India. Loo increases the day temperatures ranging between 40°C to 50°C. The hot and dry winds are unbearable. These result in heat wave causing many deaths.

Q. 30. Give reasons as to why the bulk of rainfall in India is concentrated over a few months.

Ans. The bulk of rainfall in India is concentrated over a few months beginning from June to September. During these four months, the rain bearing winds, called South-West Monsoons, blow northwards in two branches from Arabian Sea and the Bay of Bengal. These winds blow from the oceanic high pressure areas towards the low pressure areas of land and make a heavy rainfall. The Arabian Sea branch causes heavy rainfall exceeding 300 cms. along the coastal area of the Western Ghats. The Bay of Bengal branch causes heavy rainfall in the hills of Assam and Meghalaya, Mawsynram situated in Meghalaya receives the highest rainfall in the world.

LONG ANSWER TYPE QUESTIONS

Q. 1. How are the pressure and wind conditions responsible for widespread rainfall over the mainland in India? Explain.

Ans. (i) India experiences unique pressure and wind condition. 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.

(ii) In summer, a low pressure area develops over the north-western India. This causes a complete reversal of the direction of winds.

(iii) Air moves from the high pressure area over the southern Indian ocean, in a south easterly direction, crosses the equator and turns night towards the low pressure areas over the Indian subcontinent.

(iv) These winds are called south-west Monsoon winds which blow over the warm oceans, gather moisture and bring widespread rainfall over the mainland of India.

Q. 2. Describe how location and relief are important factors in determining the climate of India.

Ans. (i) The Tropic of Cancer divides the Duntry into almost two equal parts. As such, the southern part belongs to the tropical zone and the northern part lies in the subtropical zone.

(ii) The Himalayas are an effective climatic divide. They protect the Indian subcontinent from the cold and chilly winds. It is because of this that India enjoys a warmer climate in winter and temperature differences are minimized between tropical and subtropical India.

(iii) India has a triangular shape. Due to the triangular shape of the peninsular plateau, the moderating influence of the seas and ocean extends over a larger area.

(iv) The northern part of the country is far away from the sea, therefore, it experiences a continental type of climate.

Q. 3. Discuss the factors controlling the atmospheric conditions.

Ans. The climate and associated weather conditions in India are controlled by the following atmospheric conditions:

(i) Pressure and surface winds.

(ii) Upper air circulation.

(iii) Western disturbances and tropical cyclones.

(i) Pressure and Surface winds:

North-East Trade Winds: These originate from the subtropical high pressure belt of Northern Hemisphere. These are deflected by the Coriolis force and move on towards the equatorial low-pressure area. These bring little or no rain but the phenomenon of high pressure and low pressure due to shifting of monsoon trough brings advancing monsoon season and retreating monsoon season in rotation. This phenomenon enables India receives widespread rains.

(ii) Upper air circulation: Westerly flow governs the upper air circulation. This flow includes Jet Stream, a high velocity wind that blows through a narrow zone in the upper troposphere. These streams are of two types, i.e., subtropical westerly jet stream and the tropical easterly jet streams. The former blows over south of the Himalayas in summer while the later in the same season; blows over peninsular India.

(iii) Western disturbances and tropical cyclones: Western disturbances are weather phenomena of the winter months brought in by the westerly flow. These are located in the north and north-western regions of India. These jet currents move northwards in summer and give place to an easterly jet stream which flows over north India along 25°N. As we already know, low pressure develops in north of India during summer months and it attracts this easterly jet stream towards its tropical depressions.

Q. 4. Describe the distinct climatic patterns of India with suitable illustrations and explanations.

Ans. The distinct climatic pattern is popularly known as season. In other words, the monsoon type of climate is characterized by these seasons. In context of India, these changes are noticeable in her interior parts. The coastal areas do not experience much variation in temperature though there is variation in rainfall pattern. There are four main seasons identified in India: 

(i) The Cold Weather Season. 

(ii) The Hot Weather Season. 

(iii) The Advancing Monsoon Season. and 

(iv) The Retreating Monsoon Season.

(i) The Cold Weather Season: High pressure condition forms in northern plains due to cold climatic conditions. The winds are north-westerly in the Gangetic plains and  north-easterly over the Bay of Bengal. The western disturbances along with westerly wind cause winter rain over the plains and snow fall in mountains. The weather is normally fint, marked by clear sky, low temperatures and low humidity and bright sunshine.

(ii) The Hot Weather Season: Global heat belt shifts northward with the movement of sun. The months of hot weather season in India an March, April and May. The recorded temperature in Deccan plateau is 38°C (in March), Gujarat and Madhya Pradesh 42°C (in April) and north-western parts of India experience temperature of 48°C in the month of May. Loo starts blowing. Low pressure area develops in the Thar desert to Patna and Chota Nagpur plateau (viz. north-west and east-southeast). Dust storms in northern India bring down the temperature and sometimes bring light rain and cool breeze in Punjab, Haryana and U.P.

(iii) Advancing Monsoon Season: This season runs from June to September. Low pressure conditions in northern plains attract the trade winds of the Southern Hemisphere. These originate over the warm subtropical areas of the Southern Ocean. These enter in Indian peninsula as the South-West Monsoon. Early in the season, the windward side of the Western Ghats receives rainfalls more than 250 cms. The Bay of Bengal branch cause heavy rainfall in Mawsynram in Meghalaya. The Himalayas deflect the monsoon winds to the west therefore the rain goes on decreasing. Due to uncertainty and uneven distribution of rainfall, floods, and droughts are common during this season.

(iv) The Retreating Monsoon Season: After a countrywide rain till September, the monsoon trough shifts to the south and it starts retreating. This season runs from October to November. The South-West Monsoon winds weaken and start withdrawing gradually. Temperature rises and the sky becomes clear. High temperature and humidity make the weather oppressive during the day and it is called October Heat. Now low pressure conditions are transferred to Bay of Bengal which is associated with the cyclonic depressions over the Andama sea. These depressions damage life and property in deltas of peninsular rivers. Coromandel coast receives heavy winter rainfall during this season.

HOTS QUESTION

Q. 1. Why is the delta region of the eastern coast frequently struck by cyclones?

Ans. The months of October-November form a period of transition from hot rainy season to dry winter conditions. The low-pressure conditions over northern-western India get transferred to the Bay of Bengal by early November. This leads to occurrence of cyclonic depressions which originate over the Andaman Sea. These cyclones generally cross the eastern coasts of India and the delta region of the eastern coast is frequently struck by them.

Q. 2. “India has diverse climatic conditions”. Support this statement by giving three examples.

Ans. (i) The mercury occasionally touches 50°C in the Western deserts and it drops down to as low as-45° C in winter around Leh.

(ii) The annual precipitation is less than 10 cm in the north-west Himalayas as the western desert. It exceeds 400 cm in Meghalaya.

(iii) Most parts of the country receive rainfall from July to September, but some parts like Tamil Nadu coast gets most of its rain during October and November.

Q. 3. What is “October Heat”?

Ans. The months of October-November form a period of transition from a hot rainy season to dry winter conditions. The retreat of monsoons is marked by clear skies, and rise in temperature. The land is still moist. Owing to the condition of high temperature and humidity, the weather becomes rather oppressive. This is commonly known as ‘October Heat’.

Q. 4. Why is the Kulu valley more popular with the tourists?

Ans. Kulu Valley is more popular with the tourists because:

(i) The temperature in Kullu Valley in summer season is about 20°C. Thus tourists visit Kullu valley to escape the heat, dust storms, and the Loo. The weather in Kullu Valley gives respite to the tourists from the hot weather. Kulu Valley is also very picturesque and cool.

(ii) Summer season in India is from March to May. The temperature in the north-western parts of the country rises to 48°C.

(iii) Strong, gusty, hot dry winds, called “Loo” blow during the day. They even prove to be fatal.

PASSAGE BASED QUESTIONS

1. Read the given passage and answer the questions that follow:

In general, coastal areas experience less contrasts in temperature conditions. Seasonal contrasts are more in the interior of the country. There is decrease in rainfall generally from east to west in the Northern Plains. These variations have given rise to variety in lives of people – in terms of the food they eat, the clothes they wear and also the kind of houses they live in.

(i) Houses in Rajasthan have thick walls and flat roofs so as to:

(a) make them attractive.

(b) protect their houses from hot weather conditions and collect rainwater as the region receives scanty rainfall.

(c) protect the house from the storms. 

(d) clean the roofs easily.

Ans. (b) protect their houses from hot weather conditions and collect rainwater as the region receives scanty rainfall.

(ii) Houses in Terai region and in Goa and Mangalore have sloping roofs because:

(a) it enables snow to fell down easily.

(b) it enables to maintain the temperature inside the house.

(c) it enable the rainwater to flow down on the ground without getting accumulated on the roofs.

(d) it enables the winds to blow away without destroying the house.

Ans. (c) it enable the rainwater to flow down on the ground without getting accumulated on the roofs.

(iii) Houses in Assam are built on stilts because:

(a) people prefer to live in temporary houses.

(b) floods may cause heavy damage to the house.

(c) they are easy to build.

(d) it rains heavily here that leads to accumulation of water and makes the land swampy and marshy attracting ants, insects and slithering creatures.

Ans. (d) it rains heavily here that leads to accumulation of water and makes the land swampy and marshy attracting ants, insects and slithering creatures.

(iv) In general, coastal areas experience less contrasts in temperature conditions:

(a) because of being away from the mountains.

(b) because of less rainfall. 

(c) due to moderating effect of the seas. 

(d) because of being close to equator. 

Ans. (c) due to moderating effect of the seas. 

2. Read the given passage and answer the questions that follow: 

During October-November, with the apparent movement of the sun towards the south, the monsoon trough or the low-pressure trough over the northern plains becomes weaker. This is gradually replaced by a high-pressure system. The south-west monsoon winds weaken and start withdrawing gradually. By the beginning of October, the monsoon withdraws from the Northern Plains.

(i) What do you mean by ‘October heat’? 

(a) Low-pressure conditions, over north western India. 

(b) Moderate temperatures under the influence of the sea from three sides.

(c) Owing to the conditions of high temperature and humidity, the weather becomes rather oppressive during the day.

(d) The seasonal alteration of the wind systems.

Ans. (c) Owing to the conditions of high temperature and humidity, the weather becomes rather oppressive during the day.

(ii) The retreat of the monsoon is marked by:

(a) heavy rainfall in the plains. 

(b) heavy rainfall in the mountains.

(c) high temperature and low pressure in the plains.

(d) clear skies and rise in temperature. 

Ans. (d) clear skies and rise in temperature.

(iii) Which months of a year form a period of transition from hot rainy season to dry winter conditions?

(a) The months of June to September.

(b) The months of December to February.

(c) The months of October to November. 

(d) The months of March to May.

Ans. (c) The months of October to November.

(iv) Which of the following is the feature of retreating monsoon season? 

(a) The retreat of the monsoon is marked by clear skies and decrease temperature.

(b) Destructive cyclones generally occur along the eastern coasts of India causing heavy and widespread rain.

(c) The day temperatures are low and nights are hot.

(d) Low temperature and high humidity. 

Ans. (b) Destructive cyclones generally occur along the eastern coasts of India causing heavy and widespread rain.