Rainfall

Q. No. 1. India gets maximum rainfall mainly from— (BPSC Prelims, 2008)

(a) North-East Monsoon

(b) Retreating Monsoon

(c) South-West Monsoon

(d) Convectional rainfall

Answer: (c) 

Explanation:

● The South-West Monsoon is India's principal rainy season. During the northern summer, strong heating of the Asian landmass and the northward displacement of the monsoon trough/ITCZ create a large-scale pressure and circulation pattern that draws moisture-bearing winds from the Indian Ocean toward the subcontinent. 

● After crossing the equatorial region, the flow approaches India predominantly as southwesterlies. IMD treats June–September as the southwest monsoon season and states that roughly 80% of annual rainfall occurs during this period.

● Option (c), South-West Monsoon, is correct. Two broad moisture pathways are conventionally recognised: the Arabian Sea branch, which strongly affects the west coast and central/western India, and the Bay of Bengal branch, which supplies northeast India and then the northern plains. Orography, monsoon depressions, the monsoon trough and moisture convergence modify these broad paths substantially.

Hence, option (c) is correct.

Q. No. 2. The State which receives maximum rainfall due to the North-East Monsoon is— (UPPCS Prelims, 2009)

(a) Assam

(b) West Bengal

(c) Tamil Nadu

(d) Odisha

Answer: (c)

Explanation:

● The North-East Monsoon (also called the retreating monsoon) occurs mainly during October to December. During this period, winds blow from the northeast towards the southwest over the Indian subcontinent. While these winds are generally dry over northern India, they pick up moisture from the Bay of Bengal before reaching the southeastern coast of India.

As a result, the Coromandel Coast of Tamil Nadu receives substantial rainfall from:

  1. Moisture-laden northeasterly winds,
  2. Easterly waves,
  3. Low-pressure systems and depressions over the Bay of Bengal, and
  4. Tropical cyclones that frequently occur during this season.

Tamil Nadu receives the largest share of its annual rainfall from the North-East Monsoon, unlike most other Indian states that depend mainly on the South-West Monsoon.

  1. Assam, West Bengal, and Odisha receive most of their rainfall from the South-West Monsoon, while Odisha may also receive some rainfall from retreating monsoon cyclones.

Therefore, the state receiving the maximum rainfall due to the North-East Monsoon is Tamil Nadu.

Hence, option (c) Tamil Nadu is correct.

Q. No. 3. Which among the following pairs of places have the most marked differences in total annual rainfall even though located approximately along the same latitude? (UPSC Civil Services Prelims, 1993)

(a) Bengaluru and Chennai

(b) Mumbai and Visakhapatnam

(c) Ajmer and Shillong

(d) Nagpur and Kolkata

Answer: (c) 

Explanation:

● Latitude influences climate, but rainfall is controlled by far more than latitude. Distance from moisture sources, relief, slope orientation, prevailing winds, mountain barriers, rain-shadow effects and the frequency of rain-bearing systems can create enormous rainfall contrasts between places at broadly similar latitudes.

● Option (c), Ajmer and Shillong, is correct. Ajmer lies in comparatively dry Rajasthan. The Aravalli system runs broadly southwest–northeast, so it does not provide a continuous, high, transverse barrier capable of forcing the Arabian Sea branch to rise strongly over most of Rajasthan. Shillong and the Khasi Hills, by contrast, lie directly in the path of moisture-rich Bay-of-Bengal air approaching from the south. The abrupt southern escarpment of the Meghalaya Plateau forces strong orographic ascent.

● Orographic rainfall occurs when moist air is forced to ascend a mountain slope. As the air rises, it expands and cools adiabatically; condensation occurs after saturation, producing cloud and precipitation. On descending the opposite slope, the air warms and its relative humidity falls, creating a rain-shadow region.

Option (a) Bengaluru and Chennai is not correct because rainfall differs moderately due to the rain-shadow effect and the North-East Monsoon, but the contrast is not very large.

Option (b) Mumbai and Visakhapatnam is not correct because both are coastal cities receiving substantial monsoon rainfall; the difference is comparatively smaller.

Option (d) Nagpur and Kolkata is not correct because both receive significant rainfall from the South-West Monsoon, so the annual rainfall contrast is not very marked.

Hence, option (c) is correct.

Q. No. 4. Which one of the following is the correct sequence of the given Indian cities in the decreasing order of their normal annual rainfall? (UPSC Civil Services Prelims, 2005)

(a) Kochi–Kolkata–Delhi–Patna

(b) Kolkata–Kochi–Patna–Delhi

(c) Kochi–Kolkata–Patna–Delhi

(d) Kolkata–Kochi–Delhi–Patna

Answer: (c) 

Explanation:

CityApprox. annual rainfall
Kochi≈ 3000 mm
Kolkata≈ 1600 mm
Patna≈ 1100–1200 mm
Delhi≈ 700–800 mm

● Kochi receives very high rainfall because it lies close to the Arabian Sea on the windward side of the Western Ghats and receives both southwest-monsoon and additional seasonal rainfall. 

● Kolkata receives high rainfall from the Bay of Bengal branch of the summer monsoon and from monsoon depressions moving inland from the Bay.

● Patna is farther inland but still lies in the middle Gangetic plain and receives considerably more Bay-of-Bengal monsoon moisture than the western end of the northern plains.

● Delhi lies much farther west and northwest. By the time the Bay branch reaches this region, it has progressively lost moisture. Northwest India's greater continentality and its position farther from the Bay contribute to lower normal annual rainfall.

Hence, option (c) is correct.

Q. No. 5. Match List-I with List-II and choose the correct answer using the codes given below. (UPPSC Prelims, 2024)

List-I — Famous Local Storm

A. Mango Shower

B. Blossom Shower

C. Norwesters

D. Loo

List-II — Place/Area

  1. Punjab to Bihar
  2. Kerala
  3. Karnataka coastal areas
  4. West Bengal

(a) A-3, B-2, C-1, D-4

(b) A-4, B-1, C-3, D-2

(c) A-3, B-2, C-4, D-1

(d) A-1, B-3, C-2, D-4

Answer: (c)

Explanation:

● Mango Showers — Karnataka coastal areas (3). These are pre-monsoon showers of southern India, especially Kerala and coastal Karnataka, occurring during the hot-weather season. They assist the early ripening of mangoes. 

● Blossom Showers — Kerala (2). Pre-monsoon showers over coffee-growing parts of southern India help the flowering or “blossoming” of coffee plants.

● Norwesters — West Bengal (4). These violent pre-monsoon thunderstorms occur particularly over eastern and northeastern India. In Bengal they are called Kal Baisakhi. They may bring damaging squalls and lightning but can also provide useful pre-monsoon moisture to crops. 

● Loo — Punjab to Bihar (1). Loo is not a rain-bearing shower at all. It is a very hot, dry local wind that blows over parts of the northern plains during late spring and early summer before the monsoon.

Hence, option (c) is correct.

Q. No. 6. Among the following places, which one gets the least rainfall? (UPPCS Prelims, 2008)

(a) Leh

(b) Bikaner

(c) Jaisalmer

(d) Cherrapunji

Answer: (a) 

Explanation:

● Leh lies in the high-altitude cold-desert region of Ladakh. Its extreme dryness is fundamentally an orographic rain-shadow phenomenon. The Great Himalaya and associated high ranges intercept much of the moisture carried toward the region; by the time air penetrates into Ladakh, its moisture content is greatly reduced.

● Option (a), Leh, is therefore correct. Although western disturbances can bring some winter precipitation, total annual precipitation remains extremely low compared with most Indian stations. IMD's normal annual rainfall maps place the Ladakh region among India's driest climatic zones.

Hence, option (a) is correct.

Q. No. 7. The highest rainfall in India occurs in— (MPPSC Prelims, 2010)

(a) Western Ghats, Himalayan Region and Meghalaya

(b) Madhya Pradesh and Bihar

(c) Uttar Pradesh, Haryana and Punjab

(d) Andhra Pradesh and Vidarbha

Answer: (a)

Explanation:

● India's major high-rainfall belts are strongly related to orography and moisture-bearing monsoon winds. The windward western slopes of the Western Ghats and parts of northeast India, especially Meghalaya and adjoining eastern Himalayan terrain, receive very high annual rainfall.

● Option (a) is correct. Along the Western Ghats, moist Arabian Sea air is abruptly forced upward, producing heavy rainfall on the western slopes. In Meghalaya, Bay-of-Bengal moisture is funnelled toward the steep southern face of the Khasi–Jaintia uplands. Parts of the eastern Himalayan sector also receive abundant monsoonal precipitation.

● The Western Ghats create one of India's clearest rain-shadow patterns. Places on or close to the west-facing slopes can be extremely wet, whereas regions immediately to the east in interior Maharashtra and Karnataka receive much less rain.

Hence, option (a) is correct.

Q. No. 8. India has an abundant volume of rainfall but is still regarded as a thirsty land. This is due to— (UPPCS Prelims, 1994)

(a) Rapid runoff of water

(b) Quick evaporation of rainwater

(c) Concentration of rainfall during a few months only

(d) All the above

Answer: (d) 

Explanation:

● The central idea is the difference between total rainfall volume and usable water availability. A country may receive substantial annual rainfall yet face seasonal and regional water scarcity if precipitation is highly concentrated, runoff is rapid, storage is insufficient and evaporative losses are considerable.

● Option (a), rapid runoff, is correct. Intense monsoon rainfall can exceed the infiltration capacity of soils and rapidly enter streams and rivers, particularly on steep slopes, degraded catchments or heavily urbanised surfaces.

● Option (b), quick evaporation, is also relevant. India's hot pre- and post-monsoon climatic conditions can produce large evaporation and evapotranspiration losses, although the magnitude varies considerably by season and region.

● Option (c), concentration during a few months, is especially important. IMD states that roughly 80% of annual rainfall falls during the June–September southwest-monsoon season. The result is a pronounced wet-season/dry-season contrast over much of India.

● Option (d), all the above, therefore provides the best combined explanation.

Hence, option (d) is correct.

Q. No. 9. With reference to rainfall associated with the Western Ghats, consider the following statements: 

  1. The western slopes generally receive heavy rainfall from the Arabian Sea branch of the southwest monsoon.
  2. Parts of interior Maharashtra and Karnataka lie in a rain-shadow region.
  3. The Coromandel Coast receives its annual rainfall maximum during the same southwest-monsoon months for exactly the same orographic reason.

Which of the statements given above are correct?

(a) 1 only

(b) 1 and 2 only

(c) 2 and 3 only

(d) 1, 2 and 3

Answer: (b) 

Explanation:

● Moisture-rich southwesterlies from the Arabian Sea encounter the Western Ghats almost at right angles over much of the west coast. Forced ascent produces heavy orographic rainfall on their windward western slopes. Hence, statement 1 is correct.

● After crossing the crest, air descends toward the Deccan interior, warms adiabatically and its relative humidity decreases. Consequently, areas to the east of the Ghats receive significantly less rainfall than the west-facing slopes. Hence, statement 2 is correct.

● The Coromandel Coast has a different seasonal regime. Much of Tamil Nadu's major rainfall comes in October–December from northeast-monsoon/easterly systems and Bay-of-Bengal disturbances rather than from the same southwest-monsoon orographic mechanism. Hence, statement 3 is incorrect.

Hence, option (b) is correct.

Q. No.10 . Assertion (A): The monsoonal rainfall decreases as one goes towards the west and north-west in the Ganga plain.

Reason (R): The moisture-bearing monsoonal winds go higher up as one moves up in the Ganga plain. (UPSC Civil Services Prelims, 1994)

Code:

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

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

(c) A is true, but R is false.

(d) A is false, but R is true.

Answer: (c)

Explanation:

● The principal summer-rainfall gradient across the northern plains is closely associated with the Bay of Bengal branch of the southwest monsoon. As moisture-bearing air travels progressively westward and northwestward from the Bay across the Gangetic plain, repeated rainfall removes water vapour and the air mass becomes progressively less moisture-rich. Distance from the principal Bay moisture source therefore increases toward the northwest.

● Assertion (A) is correct. Rainfall broadly decreases from the wetter eastern Gangetic sector toward the drier upper Gangetic and northwestern plains. Hence, Assertion (A) is correct.

● Reason (R) does not correctly describe the mechanism. The decline is not explained by monsoon winds simply “going higher up” as they move westward. Progressive moisture depletion and increasing distance from the moisture source provide the relevant explanation. Independent reproductions of the UPSC 1994 paper also give option (c). Hence, Reason (R) is incorrect.

Hence, option (c) is correct.

Q. No. 11. Match List-I with List-II and select the correct answer. (UPSC Civil Services Prelims, 1997)

List-I — Climatic Condition

A. Chennai is warmer than Kolkata

B. Snowfall in the Himalayas

C. Rainfall decreases from West Bengal to Punjab

D. Sutlej-Ganga plain gets some rain in winter

List-II — Reason

  1. North-East Monsoon
  2. Altitude
  3. Western depressions
  4. Distance from sea
  5. Latitude

Code:

(a) A-1, B-2, C-4, D-5

(b) A-4, B-5, C-1, D-3

(c) A-5, B-2, C-4, D-3

(d) A-5, B-1, C-3, D-4

Answer: (c)

Explanation:

● A — Chennai is warmer than Kolkata → Latitude (5). Chennai lies closer to the equator and therefore experiences less pronounced winter cooling than Kolkata. Maritime influence also matters, but among the listed causes, latitude is the intended match.

● B — Snowfall in the Himalayas → Altitude (2). Temperature generally decreases with elevation in the troposphere, making high Himalayan elevations cold enough for snowfall when sufficient moisture is available. Altitude is therefore the correct match.

● C — Rainfall decreases from West Bengal to Punjab → Distance from sea (4). In examination terms, this represents the progressive inland movement and moisture loss of the Bay-of-Bengal monsoon current. “Distance from sea” is the available option that best expresses the increasing remoteness from the Bay moisture source.

● D — Sutlej-Ganga plain gets some rain in winter → Western depressions (3). These are now commonly called Western Disturbances. They are eastward-moving extra-tropical weather systems embedded in the westerly circulation and bring winter precipitation to northwest India and snowfall to the western Himalaya.

Final matching: A-5, B-2, C-4, D-3.

Hence, option (c) is correct.

Q. No. 12. The hallmark of watershed development in the semi-arid regions of India is the— (UPSC Civil Services Prelims, 1994)

(a) Establishment of sheds on a large scale so that rainwater does not evaporate

(b) Undertaking of earthworks, soil-conservation measures and tree plantation so as to conserve soil moisture and recharge groundwater

(c) Drilling deep tube wells so as to tap water at the rock-strata level

(d) Setting up a system of tanks by embanking water from seasonal rivers

Answer: (b)

Explanation:

● A watershed is the land area draining toward a common outlet. Watershed development therefore works at the catchment scale and aims to regulate runoff, conserve soil, improve infiltration, recharge groundwater and improve vegetation and land productivity.

● Option (b) is correct. Contour bunds, check structures, vegetative barriers, trenching, soil conservation, afforestation/tree planting and similar catchment treatments slow surface runoff, reduce erosion, increase infiltration and enhance soil-moisture retention. This integrated land-and-water approach is the characteristic principle of watershed development in semi-arid environments. 

Hence, option (b) is correct.


Winter Rainfall


Q. No. 1. India's Northern Plains get winter rainfall due to— (UPPCS Prelims, 1993)

(a) Western Disturbance

(b) Monsoon in Bay of Bengal

(c) Monsoon in Arabian Sea

(d) Retreating Monsoon

Answer: (a) 

Explanation:

  1. The winter rainfall of the Northern Plains, especially Punjab, Haryana, Delhi, Rajasthan, and western Uttar Pradesh, is mainly caused by Western Disturbances. 
  2. These are extratropical weather systems that originate over the Mediterranean region and move eastward with the mid-latitude westerlies.
  3. As they pass over northwestern India, they bring light to moderate rainfall in the plains and snowfall in the western Himalayas. This rainfall is particularly important for Rabi crops such as wheat, as it occurs during the winter growing season.
  4. The other options are incorrect because the Bay of Bengal and Arabian Sea monsoons are associated with the South-West Monsoon season, while the Retreating Monsoon mainly affects southeastern India, especially Tamil Nadu.

Hence, option (a) Western Disturbance is correct.

Q. No. 2. Which of the following regions of India receives winter rainfall? (RAS/RTS Prelims, 1999)

(a) Odisha – Karnataka

(b) Punjab – Tamil Nadu

(c) Arunachal Pradesh – Bihar

(d) Tamil Nadu – Karnataka

Answer: (b) 

Explanation:

● Option (b), Punjab–Tamil Nadu, is correct, but the mechanisms are completely different.

● Punjab receives modest winter precipitation from Western Disturbances moving eastward in the westerlies. The same systems can produce snowfall in the western Himalaya.

● Tamil Nadu, especially its eastern and southeastern coastal belt, receives substantial rainfall in October–December under the Northeast Monsoon (retreating Monsoon). IMD maintains separate criteria for northeast-monsoon activity and specifically uses coastal Tamil Nadu and south coastal Andhra Pradesh in its rainfall criteria.

● Therefore, remember two separate mechanisms:

Northwest India → Western Disturbances → winter rain/snow

Southeast coast → Northeast Monsoon/Bay systems → October–December rain

Hence, option (b) is correct.

Q. No. 3. Given below are two statements, one labelled Assertion (A) and the other Reason (R): (UPPCS Prelims, 2023)

Assertion (A): The Tamil Nadu coast remains dry during the South-West Monsoon season.

Reason (R): The Tamil Nadu coast is situated parallel to the Bay of Bengal branch of the South-West Monsoon and lies in the rain-shadow area of the Arabian Sea branch of the South-West Monsoon during the monsoon season. 

(a) A is false but R is true

(b) A is true but R is false

(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

Answer: (d)

Explanation:

● Tamil Nadu does receive some rainfall during June–September, but its coast is much less favoured by the southwest monsoon than India's west coast and many eastern/northeastern regions.

● The Bay of Bengal branch of the southwest monsoon moves broadly toward northeastern and northern India. Much of the Tamil Nadu coast lies approximately parallel to the prevailing direction of this branch rather than presenting a major transverse mountain barrier that would force strong orographic uplift.

● The Arabian Sea branch first encounters the Western Ghats. Heavy rainfall occurs on their western windward slopes. Air descending toward the southeastern side of peninsular India is relatively drier, so much of Tamil Nadu lies in a rain-shadow setting with respect to this branch. Hence, Assertion (A) is correct.

● The Reason correctly identifies the two standard geographical explanations: unfavourable orientation with respect to the Bay branch and rain-shadow influence of the Western Ghats. Hence, Reason (R) is correct.

● The Reason also directly explains the Assertion.

● Tamil Nadu's rainfall regime is therefore almost the seasonal inverse of much of India: while most of India experiences its principal rainfall maximum in June–September, Tamil Nadu receives a major share during the October–December northeast-monsoon season. 

Hence, option (d) is correct.

Q. No. 4. Assertion (A): Northern plains of India receive some rainfall in winter.

Reason (R): North-East Monsoon is active in winter. (UPPCS Prelims, 1998)

Code:

(a) Both A and R are true, and R is the correct explanation of A

(b) Both A and R are true, but R is not the correct explanation of A

(c) A is true, but R is false

(d) A is false, but R is true

Answer: (b)

Explanation:

● The northern plains, particularly their northwestern portion, do receive limited winter rainfall. The principal cause is the passage of Western Disturbances, not the Northeast Monsoon. Hence, Assertion (A) is correct.

● The Northeast Monsoon is an important October–December rainfall regime over southeastern peninsular India. Hence, Reason (R) is correct.

● However, the Northeast Monsoon does not cause the characteristic winter rainfall of Punjab, Haryana, Delhi and western Uttar Pradesh, Western Disturbances do. Therefore, the Reason does not explain the Assertion.

Hence, option (b) is correct.

Q. No. 5. Assertion (A): During the winter season, most parts of India are dry.

Reason (R): Most parts of the country are under the influence of northeast trade winds during the winter season. (UP RO/ARO Prelims, 2023)

Code: 

(a) Both A and R are true, but R is not the correct explanation of A

(b) A is false but R is true

(c) A is true but R is false

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

Answer: (d)

Explanation:

● During winter, the Asian landmass becomes much cooler than in summer. Relatively high pressure develops over the continental interior, and the low-level seasonal circulation over India is predominantly directed from land toward the surrounding seas.

● Because these winds originate over the continent, they generally contain little moisture. Consequently, most of India experiences a dry winter season compared with the southwest-monsoon months. Hence, Assertion (A) is correct.

● The wintertime continental winds are commonly described as northeasterly trade winds or northeast monsoon winds. Hence, Reason (R) is correct.

● Since they generally blow from land toward sea, they are initially dry and therefore explain the widespread dry conditions. Hence, Reason (R) correctly explains Assertion (A).

● The major exception occurs after these winds pass over the Bay of Bengal, where they can acquire moisture. Their subsequent interaction with southeastern India contributes to the October–December rainfall regime of Tamil Nadu and neighbouring areas. 

● Another exception to India's broad winter dryness is northwestern India, where Western Disturbances bring episodic rain and Himalayan snow.

Hence, option (d) is correct.

Q. No. 6. Which areas of India receive rainfall from the North-East Monsoon?

A. Tamil Nadu Coast

B. Gujarat Coast

C. Southern Andhra Pradesh

D. South-East Karnataka

(a) A, B, C and D

(b) A, C and D

(c) B, C and D

(d) A, B and C

Answer: (b) 

Explanation:

● The Northeast Monsoon is concentrated over the southeastern part of peninsular India. 

● A. Tamil Nadu Coast is correct. The Tamil Nadu/Coromandel coastal belt is India's most distinctive northeast-monsoon rainfall region. Hence, statement A is correct.

● C. Southern Andhra Pradesh is correct. Southern/coastal Andhra Pradesh can receive important rainfall from Bay-of-Bengal systems during the northeast-monsoon/post-monsoon season. Hence, statement C is correct.

● D. South-East Karnataka is correct. More generally, parts of south interior Karnataka receive northeast-monsoon/post-monsoon rainfall. Hence, statement D is correct.

Hence, option (b) is correct.

Q. No. 7. Assertion (A): Anti-cyclonic conditions are formed in the winter season when atmospheric pressure is high and air temperature is low.

Reason (R): Winter rainfall in Northern India causes development of anti-cyclonic conditions with low temperature. (UPSC Civil Services Prelims, 2001)

(a) Both A and R are true, and R is the correct explanation of A

(b) Both A and R are true, but R is not the correct explanation of A

(c) A is true, but R is false

(d) A is false, but R is true

Answer: (c)

Explanation:

● An anticyclone is a region of relatively high atmospheric pressure associated broadly with subsiding air and outward low-level flow. Over continental Asia during winter, strong radiational cooling favours the development of high surface pressure.

● Therefore, cold continental conditions and high pressure are associated with predominantly anticyclonic conditions over much of northern India during settled winter weather. Hence, Assertion (A) is correct.

● Winter rainfall over northern India is not what creates this anticyclonic pressure regime. Rather, rainfall episodes are introduced when Western Disturbances, which are cyclonic disturbances in the westerly circulation, pass across the region. Hence, Reason (R) is incorrect.

● In fact, a Western Disturbance temporarily disturbs the prevailing stable winter conditions, bringing cloudiness, rain, snowfall, changes in wind and temperature.

● The causal direction in the Reason is therefore reversed and conceptually wrong.

Hence, option (c) is correct.

Q. No. 8. The winter rains caused by Western Disturbances in the North-Western Plain of India gradually decrease from— (UPPCS Prelims, 2019)

(a) East to West

(b) West to East

(c) North to South

(d) South to North

Answer: (b) 

Explanation:

● Western Disturbances enter the Indian subcontinent from the west and generally move eastward under the influence of the mid-latitude westerly circulation.

● Their strongest influence over the plains is consequently concentrated toward northwestern India, particularly Punjab, Haryana, Delhi and neighbouring western areas.

● As the systems progress farther eastward, their precipitation influence over the plains generally weakens. Hence, winter rainfall associated with these systems broadly decreases from west to east in the northwestern plains.

● Option (b), west to east, is correct.

This gives an important comparison:

Winter WD rain over NW plains → decreases west to east.

Summer monsoon rain over northern plains → broadly decreases east to west.

Hence, option (b) is correct.

Q. No. 9. Given below are two statements, one labelled Assertion (A) and the other Reason (R):

Assertion (A): Rabi crops in India are predominantly cultivated in northwestern states like Punjab and Haryana.

Reason (R): The success of Rabi crops in these states depends on rain due to western tropical cyclones during winters. (UP RO/ARO Prelims, 2023)

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

(b) A is true but R is false

(c) A is false but R is true

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

Answer: (b)

Explanation:

● Rabi crops are sown mainly during the cool season and harvested in spring. Wheat is especially important in the northwestern Indo-Gangetic region, including Punjab and Haryana. Hence, Assertion (A) is broadly correct.

● Winter precipitation produced by Western Disturbances is agriculturally valuable because it supplies moisture during the Rabi growing period. The source correctly stresses its importance for Rabi agriculture.

● However, the Reason uses the expression “western tropical cyclones.” This is meteorologically incorrect. Western Disturbances are associated with the mid-latitude/extratropical westerly circulation, not tropical cyclones. Hence, Reason (R) is incorrect as worded.

● Therefore, the fact that winter rain benefits Rabi crops cannot rescue a Reason containing the wrong atmospheric-system classification.

Hence, option (b) is correct.

Q. No. 10. With reference to Western Disturbances, consider the following statements: 

  1. They approach the Indian subcontinent predominantly from the west.
  2. They are associated with the mid-latitude westerly circulation.
  3. They commonly produce winter rainfall over northwestern plains and snowfall over the western Himalaya.
  4. They are a branch of the Northeast Monsoon.

(a) 1 and 2 only

(b) 1, 2 and 3 only

(c) 2, 3 and 4 only

(d) 1, 2, 3 and 4

Answer: (b)

Explanation:

● Western Disturbances move toward India from the western sector and are embedded within the westerly circulation. IMD's forecasting manuals treat Western Disturbances and winter westerly jet streams as related winter synoptic features. Hence, statement 1 is correct.

● They are fundamentally associated with mid-latitude/extratropical atmospheric dynamics rather than the tropical monsoon circulation. Hence, statement 2 is correct.

● Their passage can generate rain over northwest Indian plains and precipitation, frequently snow at sufficiently high elevations, across the western Himalayan region. Current IMD bulletins regularly describe this pattern. Hence, statement 3 is correct.

● They are entirely distinct from the Northeast Monsoon. Hence, statement 4 is incorrect.

Hence, option B is correct.