Geography

• Option (a) is wrongly matched. The Abyssinian Plateau is the Ethiopian Highlands in the Horn of Africa, not Arabia; the two are separated by the Red Sea and the Gulf of Aden, though they share a rifting history.
• Option (b) is correctly matched. The Atlas Mountains run through Morocco, Algeria and Tunisia in north western Africa, formed by the collision of the African and Eurasian plates.
• Option (c) is wrongly matched. The Guiana Highlands are in northern South America, spanning Venezuela, Guyana, Suriname and northern Brazil, and are part of the Guiana Shield; they are not in Africa at all.
• Option (d) is wrongly matched twice over. The Okavango Basin is in southern Africa, the river terminating in an inland delta in Botswana, while Patagonia is in southern Argentina and Chile. The elimination route is simply continental: options (c) and (d) each pair a feature from one continent with a region on another, and (a) crosses from Africa to Asia, leaving (b) as the only pair internally consistent in location.

The phenomenon has two necessary conditions acting together: the inclination of the earth's axis at about 23.5 degrees to the perpendicular to the plane of the ecliptic, and the earth's revolution around the sun. Because the axis maintains a fixed orientation in space through the orbit, a condition called parallelism, the circle of illumination cuts the parallels of latitude unequally at all positions except the equinoxes, and the proportion of each parallel lying in daylight therefore changes through the year.

• Option (d) captures both conditions and is correct.
• Option (a) is incorrect because rotation produces the alternation of day and night and fixes its twenty four hour period, but a rotating earth with an upright axis would give every place a twelve hour day throughout the year.
• Option (b) is incorrect because orbital eccentricity varies the earth's distance from the sun and therefore the intensity of insolation and the speed of orbital motion, which is why the seasons are of slightly unequal length, but it does not vary day length; a circular orbit with a tilted axis would still produce the full seasonal swing.
• Option (c) is incorrect because latitude explains why the seasonal variation in day length is negligible at the equator and extreme at the poles, that is, it explains the spatial pattern of the variation, but it cannot explain why the variation occurs at all at a single fixed place, which is what the question asks. The elimination route is to ask, of each option, whether removing that factor while keeping the others would abolish the phenomenon; only the tilt survives that test.

The question asks for causes, not merely for true statements, and it defeats two of the three items on two different grounds.

• Statement 1 is correct and is causal. The Narmada occupies a linear trough of tectonic origin, a rift or graben bounded by parallel faults along the Narmada Son lineament. A stream confined between faulted blocks is constrained to follow the axis of the trough rather than the regional slope, which is why it does not join the Bay of Bengal drainage, and the same structure explains why it enters the sea by an estuary rather than building a delta, a rift valley river discharging into a subsiding coast.
• Statement 3 is incorrect, and this is the item that decides the question. The peninsular block is tilted eastward, the Western Ghats forming the high western edge and the land falling gently towards the east, which is exactly why the Mahanadi, the Godavari, the Krishna and the Kaveri all drain to the Bay of Bengal. Central India does not slope west. The Narmada and the Tapi flow west in spite of the regional gradient, not because of it, and it is the rift structure that overrides the regional slope. A candidate who accepts statement 3 has inverted the very fact that makes the Narmada anomalous and that the stem itself points to when it says most other large peninsular rivers flow to the east.
• Statement 2 is factually true, the Narmada does flow between the Vindhya range to the north and the Satpura range to the south, but it fails as an answer to why. It describes position, not cause. A river in a corridor between two ranges could in principle flow either way along that corridor; what fixes the direction is the structure.
• Statement 2 is in any case a restatement of statement 1, since the two ranges are the uplifted shoulders of the same rift. With statements 2 and 3 both out, the official answer is (a), one only. The elimination route is the stem: it tells the candidate that westward flow is the exception, so any statement asserting a general westward slope must be false.

Of the earth's total water, about 97.5 per cent is saline and about 2.5 per cent is fresh. Within that fresh fraction, roughly 68 to 69 per cent is locked in ice caps, glaciers and permanent snow, and roughly 30 per cent is groundwater. Those two together account for about 99 per cent of all freshwater. The question removes the ice and asks what dominates the remainder, and the answer is groundwater by a very large margin, so option (c) is correct.

• Option (b) is incorrect: surface freshwater in lakes and rivers is about 0.3 per cent of freshwater, which makes it the most visible and most used store but a very small one, and rivers alone are a vanishingly small fraction of that.
• Option (d) is incorrect, soil moisture being about 0.05 per cent of freshwater, and option (a) is incorrect, atmospheric water vapour being about 0.04 per cent, the smallest of the four despite its central role in the hydrological cycle because its residence time is measured in days. The governing principle, and the reason this is easier than it looks, is that stores with long residence times hold large volumes: ice and groundwater turn over in centuries to millennia, while the atmosphere turns over in about nine days.

The question is built on the standard division of geomorphic agencies into exogenic forces, driven by solar energy and gravity, and endogenic forces, driven by the earth's internal heat.

• Item 1, electromagnetic radiation, is the solar input that drives insolation, differential heating, winds, the hydrological cycle and therefore all weathering, erosion and deposition, so it qualifies.
• Item 2, geothermal energy, is the internal heat that drives mantle convection, volcanism and metamorphism, and is the ultimate source of all endogenic activity.
• Item 3, gravitational force, drives mass movement, the flow of rivers and glaciers, the settling of sediment and, in the form of tidal force, coastal work, and it is also the force behind isostatic adjustment.
• Item 4, plate movements, produce mountain building, rifting, earthquakes and volcanoes, and are the most obviously qualifying item in the set.
• Item 5, rotation, generates the Coriolis effect, which organises the planetary wind belts and ocean gyres, and produces tides in combination with lunar and solar attraction, so it operates on the surface at one remove.
• Item 6, revolution, in combination with axial tilt produces the seasons, and therefore the seasonal rhythm of glacial melt, monsoon rainfall, freeze and thaw and river regime; over long periods the orbital variations of the Milankovitch cycles govern glacial and interglacial phases and the associated eustatic changes of sea level. On this reading all six qualify and the official answer is (d). The structure of the option set gives the elimination route: no option omits item 1 or item 4 together, and once a candidate accepts that rotation and revolution both operate indirectly, only (d) contains everything.

Where a warm and a cold current converge, the mixing brings nutrient rich deep water into the sunlit surface layer, which supports a bloom of phytoplankton, which supports zooplankton, which supports commercially valuable fish in very large concentrations. The classic grounds are all of this type: the Grand Banks off Newfoundland where the Labrador current meets the Gulf Stream, the north west Pacific grounds off Japan where the Oyashio meets the Kuroshio, and the north east Atlantic grounds where the North Atlantic Drift meets cold Arctic water.

• Option (c) states this and is correct.
• Option (a) is the deliberate trap and differs from the answer by a single word: atmospheric currents are winds, and while wind drives the upwelling that produces the other great fishery type off Peru and north west Africa, the convergence being described here is oceanic.
• Option (b) is incorrect as a general proposition; river discharge does deliver nutrients and estuaries are highly productive, but large freshwater input lowers salinity and the world's principal fishing grounds are not defined by it.
• Option (d) is incorrect because an undulating shelf floor is not itself a control on productivity, although a broad and shallow shelf is a real advantage; the operative factor is nutrient supply to the photic zone, not bottom topography. The elimination route is to read options (a) and (c) against each other and notice that only one word separates them.

• Statement 1 is correct and is the entire explanation. Land and water differ fundamentally in their thermal behaviour: the specific heat capacity of water is roughly four times that of dry soil or rock, so a given input of energy raises the temperature of water far less; solar radiation penetrates several metres into water and is distributed further by turbulence and currents, while it heats only a thin surface layer of land; and evaporation from a water surface consumes a large part of the incoming energy as latent heat. Water therefore heats slowly and cools slowly, land heats rapidly and cools rapidly, and coasts under maritime influence have a small annual range while continental interiors beyond that influence have a large one. This is continentality, and Verkhoyansk in Siberia is the standard illustration.
• Statement 2 is incorrect. Continents do stand higher than ocean basins, but altitude lowers mean temperature at the lapse rate; it does not by itself widen the annual range, and the comparison intended is between the interior and the coast of the same landmass, where no systematic altitude difference is asserted.
• Statement 3 is incorrect and is nearly the opposite of the truth: strong winds promote mixing and, where they blow from the sea, carry maritime influence inland and moderate the range.
• Statement 4 is incorrect in fact; interiors are drier than coasts as a rule, and heavy rain and its attendant cloud and humidity would in any case reduce the range by damping both daytime heating and nocturnal cooling. The official answer (a) follows. The governing principle is that anything increasing moisture, cloud or maritime exchange narrows the annual range, so three of the four statements can be rejected from that single idea.

• Statement 1 is correct and is the defining commercial problem of Indian coal. Because the Gondwana coals were formed by the drifting in of plant material into basins carrying large quantities of mineral matter, the ash is distributed through the coal substance itself rather than concentrated in partings, and run of mine ash typically runs from thirty five to fifty per cent. This intergrown mineral matter is also why Indian coal washes poorly.
• Statement 2 is correct: sulphur content is generally low, commonly under one per cent in the Gondwana coals, which is a real advantage since it means lower sulphur dioxide emission per tonne burnt and it is one reason flue gas desulphurisation was long treated as a lower priority in Indian thermal plants than particulate control.
• Statement 3 is incorrect and is the item on which the whole question turns. The ash of Indian coal is rich in alumina and silica and poor in the iron, calcium and alkali fluxes that lower the melting point, so the ash fusion temperature is high, generally above about 1400 degrees Celsius. That is favourable for boiler operation, since high fusion temperature reduces slagging and clinker formation on furnace walls, but it makes the ash abrasive and difficult in gasification and in some metallurgical uses. The official answer (a) follows. Elimination narrows the field but cannot close it: statements 1 and 2 are both secure to a prepared candidate, which removes options (b) and (c), after which the choice between (a) and (d) rests wholly on the ash fusion temperature.

Laterite forms under a hot and seasonally very wet climate in which alternating wet and dry periods drive intense leaching. Silica and the soluble bases are washed out and oxides of iron and aluminium are left behind and concentrated, which is the process of laterisation.

• Statement 1 is correct: the residual iron oxide gives the soil its red to reddish brown colour, and the same enrichment is what allows lateritic material to be cut into blocks that harden on exposure and be used as building stone.
• Statement 2 is incorrect and states the opposite of the truth. Leaching removes the bases, so laterite is poor in nitrogen, phosphate, potash, lime and organic matter, and its acidity and low humus are why it needs heavy manuring and liming to be productive at all.
• Statement 3 is incorrect. Laterite occurs on the summits of the Western and Eastern Ghats, in Karnataka, Kerala, Tamil Nadu, Maharashtra, Odisha, parts of Madhya Pradesh and the hills of Assam and Meghalaya, all areas of high seasonal rainfall. Rajasthan is arid and carries desert and saline soils, and the greater part of Uttar Pradesh carries alluvium, and neither has the rainfall regime laterisation requires.
• Statement 4 is correct: tapioca, cashew, tea, coffee, rubber and coconut are the crops associated with lateritic tracts, cashew on the coastal laterites of Kerala, Karnataka and Konkan being the standard example. The official answer (c) follows. The elimination route is the rainfall requirement, which defeats statement 3 and with it options (a), (b) and (d) together, so a single correct idea about how laterite forms disposes of the whole question.

The question tests the association between geological systems and the resources found in them.

• Statement 1 is incorrect. The Gondwana system, of Upper Carboniferous to Jurassic age, holds about ninety eight per cent of India's coal, in the Damodar, Son, Mahanadi, Godavari and Wardha valleys, but petroleum and natural gas in India occur in the Tertiary sedimentary basins, Assam, Gujarat, the Cambay basin, Mumbai High and the Krishna Godavari and Cauvery offshore basins, where marine organic matter was buried in younger sediments. Coal in the Gondwana, hydrocarbons in the Tertiary, is the standard pairing.
• Statement 2 is correct. Koderma in the Hazaribagh plateau of Jharkhand is the best known mica belt in India and was long the largest producer of sheet mica in the world, the mica occurring in pegmatite veins intruded into the Archaean gneisses and schists, with the Nellore belt of Andhra Pradesh and the Bhilwara belt of Rajasthan the other two producing tracts.
• Statement 3 is incorrect. The Dharwar system is Archaean and Proterozoic, the oldest metamorphosed sedimentary system in India, and it is the great repository of metallic minerals, iron ore, manganese, gold at Kolar and Hutti, copper, lead and zinc. Petroleum is a hydrocarbon of organic origin trapped in porous sedimentary rock; it cannot occur in a highly metamorphosed Archaean system, and the mismatch is one of kind rather than of degree. The official answer (b) follows. The elimination route is statement 3, which removes option (c), after which statement 1 decides between options (a) and (b).

Kharif crops are sown with the onset of the south west monsoon in June and July and harvested in September and October; they are the monsoon crops and are water demanding. Rabi crops are sown in October and November on residual soil moisture or under irrigation and harvested in March and April; they are the winter crops and require a cool growing season with a warm ripening period.

• Items 1, 2 and 3, cotton, groundnut and rice, are all sown with the monsoon and are kharif crops, rice being the archetype and cotton and groundnut both being long duration monsoon crops of the black and red soil tracts.
• Item 4, wheat, is the archetypal rabi crop of the north western plains, requiring a cool sowing season, and it is the single item that does not belong. The official answer (c) follows. The elimination route is wheat alone: recognising it as rabi removes options (a) and (d) immediately, and rice, which no candidate will place in rabi, removes option (b), so the question can be answered from the two crops every candidate knows. The complication worth mentioning in class is that rice is grown in all three seasons in parts of the east and south, the boro crop being a summer rice, but the kharif classification is the one the question intends.

The passage carries three tests and only one region satisfies all three. Extreme climate means a large annual range of temperature, which requires continentality. Scanty rainfall points to a semi arid regime. Nomadic herding as the traditional way of life points to a grassland too dry for settled cultivation and to a pastoral society. The Central Asian steppe of Kazakhstan, Mongolia and southern Russia satisfies all three: it lies deep in the interior of the largest landmass on earth, with bitter winters and hot summers, rainfall of roughly two hundred and fifty to five hundred millimetres, and a pastoral nomadic tradition running from the Scythians through the Turkic peoples to the Mongols, which is why option (b) is correct.

• Option (a) fails on two counts: the African savannah lies in the tropics and has no extreme annual range, and its rainfall is substantial though strongly seasonal, in the region of five hundred to fifteen hundred millimetres; its pastoralists, the Maasai and the Fulani, are real but the climate description does not fit.
• Option (c) fails on the human criterion above all: the North American prairie is a temperate grassland with a genuine continental range, but its inhabitants were bison hunters rather than herders and it became the wheat belt of the continent, no pastoral nomadic tradition being associated with it.
• Option (d) fails because the Siberian tundra is a cold desert of permafrost, moss and lichen rather than a grassland, and though reindeer herding is practised there the vegetation and the temperature regime do not answer to the description of a grazing steppe. The elimination route is the herding tradition, which is what the word nomadic is doing in the passage.

Thunder is an acoustic phenomenon with a single mechanical cause. The lightning discharge heats the air in the narrow channel it passes through to something of the order of thirty thousand kelvin in a few microseconds, roughly five times the surface temperature of the sun. Air at that temperature expands explosively, and the supersonic expansion generates a shock wave which decays into the sound wave heard as thunder. The rumble rather than a single crack is a consequence of the length of the channel, sound arriving from successively more distant portions of it at successively later times, and of reflection from terrain and cloud.

• Item 1 is incorrect: clouds are suspensions of water droplets and ice crystals with no rigid surfaces, and they do not collide and produce sound in any mechanical sense; this is a folk explanation the question is deliberately offering.
• Item 2 is incorrect and is close to nonsense as drafted, lightning being the discharge that follows the separation of charge, not an agency that separates clouds.
• Item 3 is incorrect as an explanation of thunder, though it is a correct account of something else and is the most tempting of the three: violent updraughts carrying water and ice are exactly what produces the charge separation in a cumulonimbus, by collision between graupel and ice crystals in the presence of supercooled water, and so they cause the lightning. But they do not cause the sound; the sound is caused by the discharge. Since none of the three is the cause of thunder, the official answer is (d). The lesson worth drawing is the distinction between the cause of the electrification, which is item 3, and the cause of the sound, which is the thermal expansion the option set never mentions.

• Pair 1 is correctly matched. The Limboo or Limbu, with the Bhutia and the Lepcha, are among the indigenous communities of Sikkim, the Limboo and Tamang having been given Scheduled Tribe status in that State in 2003.
• Pair 2 is wrongly matched. The Karbi are a community of Assam, concentrated in the Karbi Anglong district which is administered under the Sixth Schedule through an autonomous council; they have no connection with Himachal Pradesh, whose tribal communities are the Gaddi, Gujjar, Kinnaura, Lahaula and Pangwala.
• Pair 3 is correctly matched. The Dongaria Kondh are a particularly vulnerable tribal group of the Niyamgiri hills in the Rayagada and Kalahandi districts of Odisha, a sub group of the Kondh and horticulturists of the hill slopes.
• Pair 4 is wrongly matched. The Bonda are also of Odisha, in the Bonda hills of Malkangiri district, and are among the most isolated of the particularly vulnerable tribal groups; the pairing with Tamil Nadu, whose tribal communities are the Toda, Kota, Irula, Kurumba and Kadar, is a straightforward substitution. The official answer (a) follows. The elimination route is Karbi, whose association with Karbi Anglong in Assam is well known, and rejecting pair 2 removes options (b) and (d), after which the question turns on whether the candidate places the Bonda in Odisha rather than the south.

Thermal power generation is by a wide margin the largest industrial water user in India, and the reason is the physics of the steam cycle rather than anything about the fuel. A thermal station must condense the exhaust steam leaving the turbine back to water, and it does so by rejecting the latent heat of condensation to cooling water; once through systems draw very large volumes and return them warmed, and even closed cycle systems with cooling towers consume substantial quantities through evaporation and blowdown. Cooling accounts for the overwhelming share, with smaller quantities going to ash handling, which in Indian plants is significant because of the high ash content of the coal, and to boiler make up and flue gas treatment. Studies of industrial water withdrawal in India consistently place thermal power at a large multiple of any other user, which is why plant siting is governed by water availability and why droughts have forced generating units to shut down.

• Option (d) is correct.
• Options (b) and (c) are the strong distractors and are correctly identified as water intensive per unit of output, paper and pulp requiring large volumes for pulping, washing and bleaching and textiles for dyeing, bleaching and finishing, but the question asks for the maximum consumer in aggregate, and neither industry approaches the scale of the power sector.
• Option (a), engineering, is the least water intensive of the four. The governing distinction, and the elimination route, is between intensity per unit of output and total volume consumed nationally.

• Option (a) is correct. The Ten Degree Channel, so named because it runs approximately along the parallel of ten degrees north, separates the Andaman group to the north from the Nicobar group to the south, and is about one hundred and fifty kilometres wide.
• Option (b) is incorrect. Nicobar is separated from Sumatra by the Great Channel, also called the Six Degree Channel, lying near six degrees north.
• Option (c) is incorrect. Lakshadweep is divided internally by the Eight Degree Channel, which separates Minicoy from the main Lakshadweep group, and by the Nine Degree Channel; the Eight Degree Channel also separates Minicoy from the Maldives.
• Option (d) is incorrect. Sumatra and Java are separated by the Sunda Strait, a tectonically active passage that contains Krakatoa. The elimination route is arithmetic rather than cartographic: the channels of this region are named for the latitudes they follow, so a candidate who fixes the approximate latitude of each pair can place the Ten Degree Channel without recalling the specific fact.

• Statement 1 is incorrect on both of its limbs. Coalbed methane is adsorbed on the internal surfaces of the coal matrix and is released when reservoir pressure is lowered by dewatering; it is predominantly methane, typically above ninety per cent, but is not pure, carrying carbon dioxide, nitrogen and traces of heavier hydrocarbons. Shale gas is not a mixture of propane and butane. It is natural gas generated and retained within a fine-grained organic-rich source rock, and it too is predominantly methane, which is why it is produced into the same gas infrastructure. The examiner has attached a false composition to shale gas to see whether the candidate treats the two as chemically different resources when in fact they differ in the rock that holds the gas and the technique needed to release it, not in what the gas is.
• Statement 2 is incorrect. Shale gas resources had been identified in India well before this paper, the prospective basins being Cambay, Krishna-Godavari, Cauvery, Damodar Valley, Assam-Arakan, Vindhyan and Rajasthan, and ONGC had drilled an assessment well in the Damodar Valley in West Bengal in 2011. Both statements failing, the official answer is (d).
• Statement 1 carries the elimination on its own, since the description of shale gas as propane and butane only is chemically wrong on any account and its rejection removes (a) and (c), leaving statement 2 to decide between (b) and (d).

• Statement 1 is incorrect. The Changpa are nomadic and semi-nomadic pastoralists of the Changthang plateau in eastern Ladakh, a cold desert lying above four thousand metres and continuous with the Tibetan plateau, and not of Uttarakhand. The Uttarakhand pastoral communities are the Bhotiya, the Van Gujjar and the Gaddi of the adjoining hills.
• Statement 2 is correct. The Changpa rear the Changthangi goat, whose winter undercoat is the pashm that yields pashmina, the fineness of the fibre being a physiological response to extreme cold and high altitude, which is why the same breed does not produce comparable fibre when moved to warmer ground. They also rear yak and the Changthangi sheep.
• Statement 3 is correct. The Changpa are notified as a Scheduled Tribe. The official answer is therefore (b).
• Statement 1 is both the eliminating and the decisive statement, and rejecting it removes (a) and (d) at once; a candidate who then knows the pashmina association, which is the best-known fact about the community, reaches (b) over (c) without needing to verify the Scheduled Tribe listing.

• Statement 1 is incorrect and is the whole of the question. Terrace cultivation is a soil conservation measure, not a cause of erosion. Cutting a slope into a series of level or gently backward-sloping steps reduces the effective slope length and gradient, which reduces the velocity and therefore the erosive energy of surface runoff, and allows water to infiltrate rather than concentrate. The confusion the examiner is inviting is with shifting cultivation, which does accelerate erosion by exposing bare soil on slopes after burning.
• Statement 2 is correct. Removal of forest cover exposes soil to direct raindrop impact, ends the interception and litter protection that dissipate that impact, removes root reinforcement of the soil mass and increases the proportion of rainfall that becomes overland flow. The official answer is (b), and the option set makes the item decidable on statement 1 alone: (b) is the only option that omits terrace cultivation, so a candidate who rejects statement 1 need never adjudicate statement 3.

• Option (c) is correct. Seasonal reversal of the prevailing wind direction is the defining property of the monsoon, and the word itself derives from the Arabic mausim, meaning season. The reversal arises from the seasonal migration of the thermal equator and the Inter-Tropical Convergence Zone, the differential heating of land and sea and, in the South Asian case, the crossing of the equator by the south-east trades and their deflection to the right by the Coriolis effect to become the south-west monsoon. In winter the pressure pattern reverses and the flow is offshore from the continental high.
• Option (a) is incorrect: the equatorial climate is characterised by convergence, convectional afternoon rainfall throughout the year, low pressure and light variable winds, and there is no seasonal reversal.
• Option (b) is incorrect: the Mediterranean climate arises from the seasonal shifting of pressure belts, giving westerly cyclonic rain in winter and offshore trade wind influence with drought in summer, which is a seasonal change of regime but not a reversal of wind direction in the monsoon sense.
• Option (d) fails once either of the first two is rejected. The item is decided by holding the word monsoon to its own meaning.

• Pairs 3 and 4 are correctly matched and pairs 1 and 2 are not, so the official answer is (c). The Mahadeo Hills are part of the Satpura system in Madhya Pradesh, containing Pachmarhi and the highest point of the Satpura range at Dhupgarh, and are correctly placed in central India. The Mikir Hills, now more commonly the Karbi Anglong hills, are an outlier of the peninsular block lying south of the Brahmaputra in Assam, and are correctly placed in the north-east.
• Pair 1 is incorrectly matched: the Cardamom Hills are the southernmost section of the Western Ghats, spanning Kerala and Tamil Nadu, and belong to the western side of the peninsula, whereas the Coromandel Coast is the eastern seaboard south of the Krishna delta.
• Pair 2 is incorrectly matched and is the reverse error: the Kaimur Hills are the eastern extension of the Vindhyan range running through Bihar, Uttar Pradesh and Madhya Pradesh, entirely inland, whereas the Konkan is the western coastal strip between Daman and Goa. The item is efficiently solved because the two false pairs are false in the same way, each transposing an interior or western feature to the wrong coast, and rejecting either pair 1 or pair 2 leaves only options that must be tested against the remaining pair.

• Option (b) is correct. Turkey occupies Anatolia and eastern Thrace, with the Black Sea along its entire northern coast and the Mediterranean along its southern coast, the two being connected through Turkish territory by the Bosphorus, the Sea of Marmara and the Dardanelles, which is the strategic fact that gives the country its importance and is regulated by the Montreux Convention of 1936.
• Option (a) is incorrect. Turkey does not touch the Caspian, which is an enclosed basin bordered by Russia, Kazakhstan, Turkmenistan, Iran and Azerbaijan; Turkey is separated from it by Armenia, Georgia and Azerbaijani territory.
• Option (c) is incorrect. The Gulf of Suez lies at the northern end of the Red Sea and the land between it and the Mediterranean is Egypt, traversed by the Suez Canal.
• Option (d) is incorrect. The Gulf of Aqaba and the Dead Sea lie on either side of the Wadi Araba in the Levant, between Israel and Jordan. The item is decided by knowing where the Turkish Straits are, since the whole point of Turkey's position is that it controls the only passage between the Black Sea and the Mediterranean.

• Option (c) is correct. Proceeding from south to north the order is Jakarta, Singapore, Bangkok, Hanoi. Jakarta lies on the north-west coast of Java at about six degrees south, and is the only one of the four in the southern hemisphere. Singapore sits at the southern tip of the Malay Peninsula at about one degree north, almost on the equator. Bangkok lies at the head of the Gulf of Thailand at about fourteen degrees north. Hanoi lies in the Red River delta of northern Vietnam at about twenty-one degrees north, and is the northernmost.
• Options (a) and (d) both begin with Singapore, which cannot be right because Jakarta is further south than any of the others.
• Option (b) places Hanoi second, which cannot be right because Hanoi is the northernmost of the four. The reliable method is to anchor the sequence at both ends rather than to attempt the whole ordering at once: fixing Jakarta as the southernmost and Hanoi as the northernmost leaves only Singapore and Bangkok to be ordered between them, and Singapore's position on the equator settles that.

• Statements 1, 3 and 4 are correct and statement 2 is incorrect, so the official answer is (c). A watershed is a drainage unit, the area from which runoff drains to a common outlet, and watershed development works on that unit as a whole through a ridge-to-valley sequence of treatments.
• Statement 1 is correct: contour bunding, trenching, gully plugging and check dams reduce the velocity and concentration of overland flow and therefore the detachment and transport of soil.
• Statement 3 is correct: the same structures detain runoff and increase the time available for infiltration, which is exactly how percolation tanks and check dams recharge the water table, and this is often the most visible benefit in hard-rock areas.
• Statement 4 is correct: afforestation, closure to grazing and soil moisture improvement together allow natural vegetation to re-establish, and vegetative measures are an integral part of the treatment rather than an incidental effect.
• Statement 2 is incorrect and belongs to an entirely different proposal, the interlinking of rivers, which operates at the scale of river basins and involves inter-basin transfer through link canals; it has no connection with watershed treatment, which is local and works within a single small catchment. The item is decided on statement 2 alone, and (c) is the only option that omits it.

All three pairs are incorrectly matched, so the official answer is (d).

• Pair 1 is wrong on climate. Kinnaur is a cold, high-altitude district of Himachal Pradesh in the trans-Himalayan rain shadow, known for apples, almonds, apricots and the chilgoza pine nut. Areca nut is a humid tropical palm crop, grown in Karnataka, Kerala, Assam and the coastal belt, and cannot be grown at that altitude.
• Pair 2 is wrong on region. Mewat, now Nuh, is a semi-arid district of southern Haryana on the Aravalli fringe, characterised by low rainfall, groundwater problems and pearl millet and mustard cultivation; the mango belts of northern India are in Uttar Pradesh around Malihabad, in Bihar and in Andhra Pradesh.
• Pair 3 is wrong on both region and crop ecology. The Coromandel is the eastern coastal plain south of the Krishna delta, given to rice, groundnut and coconut; soya bean is overwhelmingly a crop of the Malwa plateau of Madhya Pradesh and of Maharashtra and Rajasthan, grown on black soils in the kharif season. The governing principle is climatic matching rather than recall of any list, since each pair puts a crop in a climate that cannot support it.

All three pairs are incorrectly matched, so the official answer is (d).

• Pair 1 is wrong: under the numbering then in force, National Highway 4 ran from Thane near Mumbai through Pune, Satara, Belgaum and Bangalore to Chennai, and did not touch Hyderabad at all; the Chennai to Hyderabad axis was carried by other highways.
• Pair 2 is wrong: National Highway 6 ran from Hazira in Gujarat through Dhule, Nagpur, Raipur and Sambalpur to Kolkata, so although it terminates at Kolkata it does not begin at Mumbai, and its western terminus is on the Gujarat coast.
• Pair 3 is wrong: National Highway 15 was the western border highway, running from Pathankot through Amritsar, Bathinda, Bikaner, Jaisalmer and Barmer to Samakhiali in Gujarat, a route designed for strategic access along the frontier rather than a link between Ahmedabad and Jodhpur. The item is genuinely difficult and offers no principled elimination route, since each pair names a plausible pair of cities and requires the candidate to have the route of a specific numbered highway in memory.
• Pair 2 is the one most often accepted wrongly, because Mumbai and Kolkata are the natural termini a candidate would expect of an east-west trunk route.

Tropical cyclogenesis requires sea surface temperatures of about 26.5 degrees Celsius through a deep mixed layer, a pre-existing low level disturbance to organise convection, weak vertical wind shear, sufficient Coriolis force and a moist middle troposphere. In the South Atlantic and the south-eastern Pacific the seed disturbance is missing, because the Inter-Tropical Convergence Zone in these longitudes remains north of the equator through almost the whole year and rarely migrates into the southern tropics, so option (b) is the answer.

• Option (c) is wrong on the stem's own terms: the stem specifies tropical latitudes, where Coriolis force is adequate; it is only within about five degrees of the equator that Coriolis vanishes.
• Option (d) is wrong because tropical cyclones form over open ocean and land is not a requirement but a destroyer of them.
• Option (a) is the strongest distractor and is not wholly false, since the Benguela and Humboldt upwelling systems do keep coastal waters cool in exactly these two regions, but low sea surface temperature is a contributory condition confined to the eastern margins rather than the reason covering the whole region, and strong vertical shear operates alongside it.

• Option (d) is correct. The easternmost point of India lies in Arunachal Pradesh near Kibithu in Anjaw district at about 97 degrees 25 minutes East, and the westernmost point lies in Gujarat at Guhar Moti in the Kachchh region at about 68 degrees 7 minutes East.
• Options (a) and (c) fail because Assam lies well west of Arunachal Pradesh.
• Options (a) and (b) fail because Rajasthan, though it has the longest stretch of the western international border and is the largest State by area, does not reach as far west as the Kachchh peninsula. The trap is the association of Rajasthan with India's western extremity, which is true of the border but not of longitude.

The equatorial counter-current flows eastward in a narrow band between the westward flowing North and South Equatorial Currents. The key takes option (b). The mechanism is that the trade driven equatorial currents converge water and drive it west, piling it against the western margin of the ocean basin and raising sea level there by tens of centimetres; the resulting east-west pressure gradient forces a return flow, which surfaces as the counter-current in the zone between the two westward drifts.

• Option (a) is wrong because the Earth's rotation deflects moving water rather than driving it eastward, and it deflects in opposite senses in the two hemispheres.
• Option (c) is wrong because salinity contrasts drive the deep thermohaline circulation on a timescale of centuries, not a surface current of this speed.
• Option (d) is the serious competitor: the doldrums belt of calms is where the counter-current is found, because there the weak trades cannot oppose the return flow, but calm is the permissive condition that allows the current to surface rather than the force that generates it.

• Pair 1 is correct. Srisailam, seat of the Mallikarjuna jyotirlinga, stands on the Krishna within the Nallamala Hills of the Eastern Ghats in Andhra Pradesh.
• Pair 2 is incorrect. Omkareshwar, also a jyotirlinga, is on Mandhata island in the Narmada in Madhya Pradesh, in the trough between the Vindhya and Satpura ranges, whereas the Satmala Hills are part of the Sahyadri offshoots in the Nashik region of Maharashtra.
• Pair 3 is incorrect. Pushkar, with its Brahma temple, lies in the Aravalli near Ajmer in Rajasthan, while the Mahadeo Hills are a section of the Satpura in Madhya Pradesh containing Pachmarhi and Dhupgarh. The official answer (a) follows. Elimination route is clean and single step: Pushkar's location in the Aravalli is common knowledge, and rejecting pair 3 eliminates options (b), (c) and (d) together, leaving (a) without any need to place the Satmala Hills.

• Option (c) is correct. India holds large coal reserves but very little of coking quality: the Jharia field is the principal source of prime coking coal and is depleted and afflicted by underground fires, and Indian coal generally carries high ash of the order of twenty to forty five percent because it was formed from drift deposits, which makes it unsuitable for the blast furnace route without washing and blending. Integrated steel plants therefore import metallurgical coal, mainly from Australia, and coking coal is consistently among India's largest bulk imports by value.
• Option (a) is wrong: saltpetre, potassium nitrate, belongs to the manufacture of gunpowder, fertilizer and glass and has no role in steelmaking.
• Option (b) is wrong: rock phosphate is a phosphatic fertilizer feedstock, in which India is indeed heavily import dependent, but it is not a steel input, and it is here to catch the candidate who remembers the import dependence without remembering the industry.
• Option (d) fails once either of the first two is rejected. The governing distinction is between the quantity of a resource and its quality, India's coal problem being one of grade rather than of volume.

• Statement 1 is incorrect as written. The westerlies are the prevailing winds of the mid latitudes, blowing from the subtropical high towards the subpolar low and deflected eastward by the Coriolis force, and they occupy roughly thirty to sixty degrees in each hemisphere separately, that is, thirty to sixty degrees North and thirty to sixty degrees South. The belt described in the statement, running from thirty degrees North across the equator to sixty degrees South, would swallow both trade wind belts and the equatorial trough, where the winds are easterly or calm.
• Statement 2 is correct. Winter rain over Punjab, Haryana, western Uttar Pradesh and Jammu and Kashmir is brought by western disturbances, extratropical low pressure systems that form over the Mediterranean and the Caspian region and are steered across Iran, Afghanistan and Pakistan into north western India by the subtropical westerly jet stream, which shifts south of the Himalaya in winter. That rain matters out of proportion to its quantity because it falls on the standing rabi wheat crop. The official answer (b) follows. Elimination route: statement 2 is standard monsoon material, and its acceptance removes options (a) and (d).

• Option (b) is correct. The passage describes the diurnal convectional regime of the equatorial climate. Intense insolation on a nearly vertical Sun heats a humid surface, air rises in strong convection currents through the day, towering cumulonimbus builds by early afternoon, and a violent but short lived thunderstorm follows, often called the four o'clock rain, after which the sky clears. The decisive words are each day is more or less the same: the equatorial belt has small annual range of temperature, rain in every month and effectively no seasons, only a daily rhythm, and the writer describes a day rather than a season for that reason.
• Option (a) is wrong: the savannah has a sharply marked wet and dry season, so no day can stand for the year.
• Option (c) is wrong for the same reason, the monsoon being defined by seasonal reversal of wind and a long dry season.
• Option (d) is wrong: the Mediterranean regime has dry warm summers and wet mild winters, and its summer is the season of drought, not of daily thunderstorms. The governing principle is that a passage describing a typical day rather than a typical year can only describe a climate without seasons.

The Godavari and the Krishna were linked through the Pattiseema lift irrigation scheme, commissioned by Andhra Pradesh in September 2015, which lifts water from the Godavari at Pattiseema in West Godavari district into the Polavaram right main canal and thence to the Krishna at Prakasam barrage. Its significance was that it was presented as the first river link of the national interlinking programme actually to be executed, delivering Godavari surplus to the Krishna delta ahead of the completion of the Polavaram project itself. Hence (b).

• Option (a) is wrong: no Cauvery-Tungabhadra link has been executed, and the Tungabhadra is in any case a Krishna tributary.
• Option (c) is wrong: the Mahanadi-Godavari link is a proposal under the peninsular component and Sone is a Ganga tributary.
• Option (d) is wrong: the Par-Tapi-Narmada link remained a proposal and has since faced sustained opposition. The elimination route is that three options name links that exist only on the National Water Development Agency's map, and only one names a scheme that had actually delivered water.

• Pair 1 is incorrect: Bodhgaya lies in Bihar, in the historic region of Magadha, whereas Baghelkhand is the plateau region of eastern Madhya Pradesh around Rewa and Satna.
• Pair 2 is correct: Khajuraho lies in Chhatarpur district of Madhya Pradesh, squarely within Bundelkhand, the region straddling Madhya Pradesh and Uttar Pradesh that takes its name from the Bundela Rajputs.
• Pair 3 is incorrect: Shirdi is in Ahmednagar district in western Maharashtra, whereas Vidarbha is the eastern region of the State around Nagpur and Amravati.
• Pair 4 is incorrect: Nashik lies in northern Maharashtra, in the tract conventionally called Khandesh or North Maharashtra, whereas Malwa is the plateau of western Madhya Pradesh around Indore and Ujjain.
• Pair 5 is correct: Tirupati is in Chittoor district of Andhra Pradesh, within Rayalaseema, the southern interior region of the State. Hence 2 and 5, giving (c). The elimination route is efficient: recognising either that Bodhgaya is in Bihar or that Shirdi is not in Vidarbha removes three of the four options, since only (c) excludes both. The item tests regional rather than administrative geography, which is what makes it harder than it looks.

• Statement 1 is incorrect. The Teesta rises in the Pauhunri and Cho Lhamu region of North Sikkim, conventionally traced to Cho Lhamu lake, whereas the Brahmaputra rises as the Yarlung Tsangpo from the Chemayungdung and Angsi glacier region near Mount Kailash and Lake Mansarovar in Tibet. Two rivers of very different orders, separated by the main Himalayan axis, cannot share a source.
• Statement 2 is correct. The Rangeet rises in West Sikkim below Kanchenjunga, flows south and joins the Teesta near Melli on the Sikkim and West Bengal boundary; it is the principal tributary of the Teesta.
• Statement 3 is incorrect and is the more instructive error. The Teesta does not reach the sea at all as an independent river. It enters Bangladesh below Jalpaiguri and joins the Brahmaputra, in its Jamuna course, near Chilmari, so its waters reach the Bay of Bengal only through the Brahmaputra and Meghna system. Rejecting statement 1 eliminates (a) and (d); statement 3 then eliminates (c), leaving (b). Governing principle: for any Himalayan river, fix the source with reference to the main range and fix the mouth by identifying the trunk stream it joins, since a tributary that merges before the coast never has a mouth of its own.

• Statement 1 is incorrect. The Himalayas extend across far more than five States and Union Territories, running through Jammu and Kashmir and Ladakh, Himachal Pradesh, Uttarakhand, Sikkim, West Bengal in its northern districts, and Arunachal Pradesh, with the associated ranges extending into the north eastern States. On any reasonable reckoning the count exceeds five.
• Statement 2 is incorrect. The Western Ghats run through six States, Gujarat at their northern extremity in the Dangs, then Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu. The count of five is obtained only by omitting Gujarat, which is precisely the omission the statement is built on, and the UNESCO World Heritage serial inscription of 2012 covers sites across six States.
• Statement 3 is correct. Pulicat Lake, the second largest brackish water lagoon in India, lies across the Andhra Pradesh and Tamil Nadu boundary, with much the greater part in Andhra Pradesh and the southern portion, including the Sriharikota barrier, straddling the line into Tamil Nadu. Two States, and no more. Rejecting statement 1 eliminates (a) and (d), and rejecting statement 2 then eliminates (c), leaving (b). Governing principle: every statement here turns on the word 'only', and each of the two false ones fails by a single omitted State or region. Count the units at the margins of a feature, since that is where these items are constructed.

• Statement 1 is incorrect, and the error is a single substituted word. The Indian Ocean Dipole is defined by the sea surface temperature gradient between the tropical western Indian Ocean, off the Horn of Africa, and the tropical eastern Indian Ocean, off Sumatra and Java. The statement replaces the eastern Indian Ocean with the eastern Pacific, which is the pole used to define El Nino, not the Dipole. The Dipole is measured by the Dipole Mode Index, the difference of the anomalies between those two Indian Ocean boxes; a positive phase has the western pole warmer and the eastern cooler.
• Statement 2 is correct. A positive Dipole strengthens moisture convergence over the Indian subcontinent and has repeatedly offset the suppressing effect of El Nino on the monsoon, the drought year of 1997 despite a very strong El Nino, and the deficient year of 2002 despite a weak one, being the standard contrasting pair. The two modes are not independent, and forecasting practice treats their combined state rather than either alone. Rejecting statement 1 eliminates (a) and (c), leaving (b) against (d). Governing principle for the subject teacher: the Dipole is an Indian Ocean mode and both its poles lie in the Indian Ocean. Any definition reaching into the Pacific has confused it with the Southern Oscillation.

• Option (a) is correct. Great Nicobar is the southernmost island of the Nicobar group, and Indira Point at its southern tip is the southernmost point of India. The Great Channel, roughly one hundred and forty five kilometres wide, separates Indira Point from Banda Aceh at the northern tip of Sumatra, which makes Sumatra by a wide margin the nearest of the four. This proximity is the reason the Andaman and Nicobar chain is geologically continuous with the Arakan Yoma and the Sumatran arc, all of them part of the same accretionary ridge above the Sunda subduction zone, and it is why the 2004 Sumatra Andaman earthquake and tsunami struck the Nicobars so severely.
• Option (b) is wrong: Borneo lies far to the east, beyond Sumatra and the Java Sea.
• Option (c) is wrong: Java lies south east of Sumatra and is correspondingly further.
• Option (d) is the distractor a candidate reaches for by reflex, Sri Lanka being the familiar neighbour, but it lies to the west across the whole width of the Bay of Bengal, well over a thousand kilometres away, and the mental habit of associating India with Sri Lanka is exactly what the item exploits. Governing principle: the Andaman and Nicobar islands lie in the eastern Bay of Bengal and are nearer to South East Asia than to the Indian mainland, Port Blair being closer to Myanmar and Great Nicobar closer to Indonesia.

• Statement 1 is correct. The Aral Sea is the standard textbook case of anthropogenic desiccation. Soviet era diversion of the Amu Darya and Syr Darya for cotton irrigation from the 1960s onward cut off the inflow to an endorheic basin, and with evaporation continuing unchecked the lake lost the great majority of its area and volume and split into separate remnant water bodies, leaving the salt and pesticide laden Aralkum desert behind.
• Statement 2 is incorrect. The Black Sea is a large marine basin connected to the Mediterranean through the Bosporus and Dardanelles and fed by the Danube, Dnieper and Don; it has serious pollution and anoxia problems in its deep water, but it has not shrunk or dried up.
• Statement 3 is incorrect. Lake Baikal is the deepest and most voluminous freshwater lake on Earth, holding roughly a fifth of the world's unfrozen surface fresh water; it faces pollution and species pressure but no desiccation. Elimination route: the governing distinction is hydrological, between a closed basin with no outlet, where any diversion of inflow translates directly into loss of area, and an open or connected basin, where it does not. Only the Aral Sea is endorheic among the three, so only statement 1 can be correct and (a) follows without any need for further recall.

Hence (a).

• Pair 1 is correctly matched. Aleppo is Syria's largest city and its industrial and commercial centre, and the battle for it from 2012 to 2016 was the defining engagement of the Syrian civil war.
• Pair 2 is incorrectly matched. Kirkuk is in northern Iraq, the centre of a major oil field and a disputed city claimed by both Baghdad and the Kurdistan Regional Government; federal forces took control of it in October 2017 after the Kurdish independence referendum.
• Pair 3 is incorrectly matched. Mosul is Iraq's second city, on the Tigris, held by the Islamic State from 2014 and recaptured after a nine month campaign that ended in July 2017.
• Pair 4 is correctly matched. Mazar i Sharif is the principal city of northern Afghanistan and the seat of the shrine attributed to Ali. Only pairs 1 and 4 are correct, so the answer is (b). The elimination is quick and does not require all four facts. Kirkuk and Mosul are both Iraqi, and once either is recognised as such, options (a), (c) and (d) each contain a wrong pair and fall away, leaving only (b). Governing principle: the examiner has deliberately displaced two Iraqi cities into Yemen and Palestine, so a candidate who has the Iraq theatre clear in mind needs nothing else.

Hence (b).

• Statement 2 is incorrect and it is the obvious reject that opens the question. The early Earth had essentially no free oxygen. Its primordial atmosphere was lost, and the secondary atmosphere produced by degassing of the interior was dominated by water vapour, carbon dioxide, nitrogen, methane and ammonia. The statement inverts the actual composition on both counts, asserting abundant oxygen and absent carbon dioxide when the truth is the reverse, and the figure of 54 per cent has no basis. Free oxygen is a product of life, not a precondition for it.
• Statement 3 is correct and follows directly. Photosynthesising cyanobacteria released oxygen, which was first consumed by dissolved iron and by reduced minerals, producing the banded iron formations, and only when those sinks were exhausted did oxygen accumulate in the atmosphere in the Great Oxidation Event around 2400 million years ago. That accumulation in turn created the ozone screen and made the colonisation of land possible, so the biosphere reconstructed the atmosphere it now depends on.
• Statement 1 is correct as the key takes it. Reversals of the geomagnetic field are recorded in the magnetisation of successive lavas and in the symmetrical magnetic striping of the ocean floor about the mid ocean ridges, which was the decisive evidence for sea floor spreading, and the most recent full reversal, the Brunhes Matuyama, was about 780,000 years ago. So statements 1 and 3 are correct and the answer is (c). Elimination route: rejecting statement 2 removes options (b) and (d) at once, leaving (a) against (c), and statement 3 is then almost self evidently true for anyone who knows that atmospheric oxygen is biogenic.

Hence (c).

• Option (a) is correct. The lake at Kodaikanal in the Palani hills is man made, created in 1863 when Sir Vere Henry Levinge dammed a hollow in the hills and stocked it with fish, and it forms the centre of a hill station laid out by Europeans in the nineteenth century.
• Option (b) is wrong. Kolleru is a natural shallow freshwater lake lying between the deltas of the Krishna and the Godavari, functioning as a natural flood balancing reservoir between the two river systems; it is a Ramsar site and was declared a wildlife sanctuary.
• Option (c) is wrong. Nainital is a natural lake of tectonic origin, occupying a depression formed along a fault in the Kumaon hills, and its crescent shape follows that structural line.
• Option (d) is wrong. Renuka is the largest natural lake in Himachal Pradesh, also a Ramsar site, and is associated in tradition with the mother of Parashurama, its outline being said to resemble a reclining woman. Governing principle for this recurring question type: hill station lakes in the peninsular hills are very often engineered, because the Palanis and the Nilgiris have no natural lake basins of any size, whereas lakes in the Himalaya and the sub Himalaya are commonly tectonic or glacial, and the large lakes of the coastal plains are lagoons or deltaic depressions. Since three of the four options are recognised natural water bodies with Ramsar or sanctuary status, the odd one out is the constructed one.

Hence (a).

• Statement 1 is incorrect and it is the only statement needed, since it appears in options (a), (c) and (d) and rejecting it leaves (b) at once. Organic matter increases water holding capacity rather than reducing it, and it does so in two ways: humus is colloidal and hydrophilic and holds several times its own weight in water, and organic matter binds mineral particles into stable aggregates, creating the pore structure in which water is retained against gravity. Raising soil organic carbon is the standard recommendation for drought resilience, which makes the statement not merely wrong but the reverse of settled practice.
• Statement 2 is incorrect. Soil is central to the sulphur cycle. The bulk of soil sulphur is held in organic matter and is released to the plant available sulphate form by microbial mineralisation, sulphur oxidising bacteria such as Thiobacillus convert reduced forms to sulphate, and under waterlogged and anaerobic conditions sulphate reducing bacteria run the reaction the other way to produce hydrogen sulphide. Sulphur deficiency in Indian soils, aggravated by the shift to high analysis fertilisers that carry no incidental sulphur, is a live agronomic problem.
• Statement 3 is correct. Irrigation water carries dissolved salts, and where drainage is poor and evaporation high the water leaves while the salts remain and accumulate in the root zone; a rising water table brought on by canal irrigation carries salts up by capillary action to the surface. The salinity and waterlogging of parts of the canal commands in Punjab, Haryana and western Uttar Pradesh is the standard Indian illustration.

Hence (b).

• Statement 1 is correct. Barren Island is the only confirmed active volcano in South Asia and lies within Indian territory, in the Andaman Sea, on the volcanic arc produced by the subduction of the Indian plate beneath the Burma plate; the same arc carries Narcondam, which is classified as dormant.
• Statement 2 is incorrect on both the distance and the direction. Barren Island lies roughly 135 to 140 kilometres north east of Port Blair, which is in the Andaman group, whereas Great Nicobar is the southernmost island of the Nicobar group, several hundred kilometres to the south. The number in the statement is borrowed from the true distance and attached to the wrong reference point, which is the trap.
• Statement 3 is incorrect. After a long dormancy from 1803 the volcano resumed activity in 1991, but it has erupted repeatedly since, with episodes in 1994 and 1995, in 2005 following the great Sumatra Andaman earthquake, and again in 2017, when a National Institute of Oceanography vessel observed lava and ash emission at close quarters. Elimination route: statement 1 is standard and secure, which removes options (b) and (c); the choice between (a) and (d) then rests on statement 3, and a candidate who followed the 2017 reports rejects it directly.

Hence (a).

• Pair 1 is correctly matched. Catalonia is an autonomous community of Spain with Barcelona as its capital, and its unilateral independence referendum of October 2017 and the direct rule that followed under Article 155 of the Spanish Constitution are the reason it appeared in the news.
• Pair 2 is incorrectly matched. Crimea is a peninsula on the northern Black Sea, part of Ukraine and annexed by Russia in 2014; it has no connection with Hungary, which is landlocked.
• Pair 3 is correctly matched. Mindanao is the large southern island of the Philippines, the seat of the long Moro insurgency and of the Bangsamoro autonomy process, and the site of the siege of Marawi in 2017 after which martial law was imposed.
• Pair 4 is incorrectly matched. Oromia is the largest regional state of Ethiopia, home of the Oromo, whose protests from 2015 led to the resignation of the Prime Minister and the accession of Abiy Ahmed in April 2018. Nigeria's regions in the news are the north east under Boko Haram and the Niger Delta. Only pairs 1 and 3 are correct, so the answer is (c). The elimination is efficient: recognising Crimea as Ukrainian removes options (a) and (d), and recognising Oromia as Ethiopian removes (b), leaving (c) without any need to verify the two correct pairs.

Hence (c).

On 21 June the Sun is vertically overhead at the Tropic of Cancer, the northern hemisphere summer solstice. The circle of illumination is then tangential to the Arctic and Antarctic Circles in such a way that the entire area north of the Arctic Circle receives continuous daylight and the entire area south of the Antarctic Circle receives continuous darkness.

• Option (a) is therefore correct, since at the Arctic Circle the Sun grazes the horizon at midnight without setting.
• Option (b) is wrong for the opposite reason, since the Antarctic Circle is then in polar night and the corresponding statement about it holds on 22 December, not 21 June.
• Option (c) is wrong because the Sun is overhead at the Equator only at the equinoxes, on about 21 March and 23 September.
• Option (d) is wrong because the Sun is overhead at the Tropic of Capricorn on about 22 December, the winter solstice. The governing principle is the annual migration of the vertical rays between the two tropics, and every option is generated by displacing that fact to the wrong date or the wrong hemisphere.

The New World means the Americas and the Old World means Eurasia and Africa. Tobacco was domesticated in the Americas, cocoa in Mesoamerica and the Amazon basin, and rubber, Hevea brasiliensis, in the Amazon, so all three in option (a) are New World domesticates carried east after 1492, which makes (a) correct.

• Option (b) fails on cotton, which has both New World and Old World domestications, the Old World species Gossypium arboreum and Gossypium herbaceum having been cultivated in the Indus valley and in Africa long before contact, so cotton cannot be presented as a New World introduction into the Old World.
• Option (c) fails twice, since coffee was domesticated in Ethiopia and Yemen and sugarcane in New Guinea and Southeast Asia, both Old World.
• Option (d) fails on coffee and on wheat, wheat being the founder crop of the Fertile Crescent. The elimination route is quick for a prepared candidate, since coffee and wheat are unambiguously Old World and remove options (c) and (d), and the residual decision between (a) and (b) rests on cotton alone.

• Pair 1 is correct. Pandharpur in Solapur district of Maharashtra, the seat of the Vithoba temple and the destination of the Varkari pilgrimage, stands on the Bhima, which is locally called the Chandrabhaga at Pandharpur because of the crescent shape of its bend there.
• Pair 2 is correct. Tiruchirappalli in Tamil Nadu stands on the Cauvery, at the point where the river divides around Srirangam island between the Cauvery and the Coleroon.
• Pair 3 is incorrect. Hampi, the Vijayanagara capital in Karnataka, stands on the Tungabhadra. The Malaprabha is a different Krishna tributary and is associated with Aihole, Badami and Pattadakal, the early Chalukyan sites. Since pairs 1 and 2 hold and pair 3 fails, the official answer (a) follows. The elimination route is Hampi and the Tungabhadra, which is standard knowledge and removes options (b), (c) and (d) at a stroke, so the item is decided by one fact even though it appears to demand three.

• Pair 1 is correct. Albania faces the Adriatic Sea on its western coast, north of the Strait of Otranto, along with Italy, Slovenia, Croatia, Bosnia and Herzegovina and Montenegro.
• Pair 2 is incorrect. Croatia is an Adriatic country, not a Black Sea one. The Black Sea is bordered by Turkey, Bulgaria, Romania, Ukraine, Russia and Georgia.
• Pair 3 is correct. Kazakhstan holds the long northern and north eastern shore of the Caspian, one of its five littoral states along with Russia, Azerbaijan, Iran and Turkmenistan.
• Pair 4 is correct. Morocco has a Mediterranean coast on its north, facing Spain across the Strait of Gibraltar, in addition to its longer Atlantic coast.
• Pair 5 is incorrect. Syria borders the Mediterranean, not the Red Sea, whose littoral states are Egypt, Sudan, Eritrea, Djibouti, Saudi Arabia, Yemen, Israel and Jordan. Since pairs 1, 3 and 4 hold, the official answer (b) follows. The elimination is efficient. Recognising that Syria has no Red Sea coast removes options (c) and (d) at once, and recognising Croatia as an Adriatic state removes (a), leaving (b) without any need to adjudicate the Caspian or Moroccan pairs.

• Pair 1 is correct. The Yamunotri glacier lies on the Bandarpunch massif in Uttarkashi district and feeds the Yamuna.
• Pair 2 is correct. The Bara Shigri glacier in the Lahaul valley of Himachal Pradesh drains to the Chandra, which joins the Bhaga at Tandi to form the Chandrabhaga or Chenab.
• Pair 3 is incorrect. The Milam glacier in the Pithoragarh district of Kumaon feeds the Goriganga, a tributary of the Kali or Sharda. The Mandakini rises from the Chorabari glacier near Kedarnath, which is the association the pair displaces.
• Pair 4 is correct. The Siachen glacier in the eastern Karakoram feeds the Nubra, a tributary of the Shyok and thus of the Indus.
• Pair 5 is incorrect. The Zemu glacier in Sikkim, on the eastern flank of Kangchenjunga, feeds the Teesta. The Manas rises in Bhutan and Tibet and is a Brahmaputra tributary, unconnected to Zemu. Since pairs 1, 2 and 4 hold, the official answer (a) follows. The reliable elimination is Zemu and the Teesta, which is standard and removes options (c) and (d), after which the Milam pairing alone decides between (a) and (b).

All three are reservoirs behind dams, so (d) is correct. Aliyar is a reservoir in the Anaimalai foothills of Coimbatore district in Tamil Nadu, part of the Parambikulam Aliyar project. Isapur is a dam on the Penganga, a Godavari tributary, in Yavatmal district of Maharashtra. Kangsabati is a reservoir on the Kangsabati river in Bankura district of West Bengal, serving one of the largest irrigation commands in the State.

• Option (a) is wrong because India's uranium is associated with Jaduguda and the Singhbhum thrust belt in Jharkhand, Tummalapalle in Andhra Pradesh and Lambapur Peddagattu in Telangana, none of which are these.
• Option (b) is wrong because Indian tropical rain forest is confined to the Western Ghats, the north east and the Andamans as a contiguous biome, and three scattered locations across Tamil Nadu, Maharashtra and West Bengal cannot share it.
• Option (c) is wrong because India's notable cave systems are the Meghalaya limestone caves, Borra in Andhra Pradesh and Belum in Kurnool. The elimination route is the geographical spread itself, since the three names lie in three widely separated States with nothing geological or ecological in common, which leaves an engineered feature, and among the four options only a reservoir is engineered.

Dew forms when a surface loses heat by outgoing longwave radiation during the night, cools below the dew point temperature of the adjacent air, and water vapour condenses directly on it. The condition for dew is therefore rapid nocturnal radiative cooling, which requires a clear sky, calm air and high relative humidity. On a cloudy night the outgoing terrestrial radiation is intercepted by the cloud layer and returned downward, the surface does not cool to the dew point, and no dew forms.

• Option (b) states this and is the official answer.
• Option (c) is not merely wrong but inverted, since cloudy nights are warmer at the surface than clear nights, which is precisely why dew fails to form.
• Option (d) is wrong because clouds do not deflect wind to ground level, and although wind does inhibit dew by mixing the air near the surface, that is not a cloud effect.
• Option (a) is the real distractor and deserves a note, since clouds do absorb terrestrial longwave radiation. It is rejected because absorption alone, without re emission back towards the surface, would not keep the ground warm; the operative mechanism is the return of energy downward.

• Statement 1 is correct. Rice occupies the largest area of any kharif crop in India, of the order of forty million hectares, and it is also the largest single crop by area in the country taken across seasons.
• Statement 2 is incorrect. Kharif oilseeds, dominated by soyabean and groundnut with sesamum, castor and sunflower alongside, occupy roughly eighteen to nineteen million hectares, whereas kharif jowar occupies only about two to three million hectares, jowar having declined steeply over decades as coarse cereals lost area to oilseeds and to rice. The comparison is not close.
• Statement 3 is correct. Cotton occupies of the order of twelve million hectares against about five million hectares for sugarcane, a ratio of well over two to one.
• Statement 4 is incorrect. Area under sugarcane has fluctuated with the price cycle and with arrears of cane payment, rising and falling, and has not steadily decreased; the word steadily is what defeats it. Since statements 1 and 3 hold, the official answer (a) follows. The practicable route is the pair of absolute claims, since coarse cereals cannot outrank oilseeds in a country that is the world's largest importer of vegetable oil, and steady decline is a strong claim that agricultural area data rarely support.

• Pair 1 is incorrect. The Mekong rises on the Tibetan plateau, runs through China, Myanmar, Laos, Thailand and Cambodia and empties through its delta in southern Vietnam into the South China Sea; the Irrawaddy and Salween are the rivers that reach the Andaman Sea.
• Pair 2 is incorrect. The Thames flows eastward through London and enters the North Sea through its estuary, the Irish Sea lying to the west of Britain and receiving the Mersey and the Severn by way of the Bristol Channel.
• Pair 3 is correct, the Volga being the longest river in Europe and draining into the Caspian, an inland basin, which is why it is a river of internal drainage.
• Pair 4 is correct, the Zambezi crossing southern Africa past the Victoria Falls and reaching the Indian Ocean through Mozambique. The answer is 3 and 4, giving (c).

The description matches cotton on every count, giving (a). Cotton is grown in the subtropical belt, is destroyed by frost, requires a long frost free period of about two hundred and ten days for the boll to mature, and does well on the moderate rainfall of fifty to one hundred centimetres characteristic of the Deccan and Gujarat, the black regur soil retaining moisture through the dry spell.

• Option (b) is wrong because jute needs heavy rainfall of about one hundred and fifty to two hundred centimetres with high humidity and grows on the alluvium of the Ganga Brahmaputra delta.
• Option (c) is wrong because sugarcane is tropical, needs a longer growing period of ten to fifteen months and tolerates heavier soils.
• Option (d) is wrong because tea requires high rainfall and well drained sloping ground and is a plantation shrub rather than a field crop. The rainfall figure alone eliminates jute and tea, and the word subtropical eliminates sugarcane.

• Statement 2 is correct and is the substance of the research the question draws on. Ocean Mean Temperature integrates heat through the upper ocean layer rather than sampling only the skin, so it captures the heat content actually available to drive convection, and the January to March value in the south western Indian Ocean has been shown to predict whether the following monsoon will be above or below the long period average with greater accuracy than sea surface temperature.
• Statement 1 is treated as incorrect by the official key. The keyed answer is therefore 2 only, giving (b), with (a) and (d) rejected outright and (c) rejected only on the treatment of statement 1.

The Siachen glacier lies in the eastern Karakoram, and its meltwater feeds the Nubra river, which flows south from the glacier snout to join the Shyok. The glacier therefore lies at the head of and to the north of the Nubra valley, giving (d).

• Option (a) is wrong because Aksai Chin lies far to the east, on the Tibetan plateau margin, so Siachen is west of it rather than the reverse.
• Option (b) is wrong because Leh lies to the south, on the Indus, and the route to the glacier runs north from Leh over the Khardung La into the Nubra valley.
• Option (c) is wrong because Gilgit lies well to the west in the territory held by Pakistan, so the glacier is to its east. Fixing the Nubra valley on the mental map is the single step that answers the question, since the glacier and the valley form one continuous drainage line.

• Statement 2 is correct. The Central Ground Water Authority was constituted in 1997 under section 3 of the Environment Protection Act of 1986, on the direction of the Supreme Court, and it draws its regulatory power to notify and restrict extraction from that statute rather than from any dedicated groundwater law.
• Statement 3 is correct. India irrigates more land from groundwater than any other country, ahead of China and the United States, the tubewell having displaced canal and tank irrigation since the green revolution.
• Statement 1 is treated as incorrect. Assessment is carried out by unit, that is by block, taluka or mandal rather than by district, and the proportion falling in the overexploited and critical categories is materially lower than thirty six per cent, though it rises if the semi critical category is added. The answer is 2 and 3, giving (b).

• Statement 1 is incorrect. Jet streams are a consequence of the thermal gradient between equator and pole and of the Coriolis deflection, both of which operate in both hemispheres, so polar front and subtropical jets exist north and south of the equator.
• Statement 2 is correct. The eye is a feature of intense and well organised tropical cyclones, appearing once the system is mature and the circulation symmetric; weaker tropical storms, and the extratropical and temperate cyclones which form on fronts, have no eye at all.
• Statement 3 is incorrect and is the discriminating statement. The eye is the warmest part of the storm, not the coldest, because air subsides in the centre and warms adiabatically as it descends, which is exactly why the eye is cloud free and calm; the warm core is what distinguishes a tropical cyclone from a temperate one. Only statement 2 stands, giving (c). The physical reasoning on subsidence disposes of statement 3 without any recall of figures.

All four are salt lakes of the Nagaur and Sikar belt of Rajasthan, part of the same inland drainage system as the much better known Sambhar Lake, where evaporation in an arid basin with no outlet concentrates dissolved salts and supports commercial salt extraction.

• Option (a) is wrong because Indian glaciers carry Himalayan names such as Siachen, Gangotri and Zemu.
• Option (b) is wrong because mangroves occur on the deltaic and tidal coasts, Sundarbans, Bhitarkanika, Pichavaram, not in interior Rajasthan.
• Option (c) is wrong because although Sambhar itself is a Ramsar site, these four are not designated as such. Hence (d). The unifying logic is aridity plus internal drainage, which is the standard setting for saline lake formation and is worth teaching as a process rather than as a list.

• Statement 1 is incorrect and is the decisive statement: licensing of exploration and exploitation in the Area, meaning the seabed beyond national jurisdiction, is the exclusive function of the International Seabed Authority established under the United Nations Convention on the Law of the Sea. The Global Ocean Commission was a time bound independent advocacy initiative that produced recommendations on ocean governance and had no licensing power at all.
• Statement 2 is correct: India holds ISA contracts for polymetallic nodules in the Central Indian Ocean Basin and for polymetallic sulphides in the Indian Ocean ridges, and is designated a pioneer investor.
• Statement 3 is correct: rare earth elements occur in deep sea muds and in ferromanganese crusts on the ocean floor. Hence 2 and 3, giving (b). The general rule worth teaching is that bodies named Commission or Panel in ocean governance advise, while the Authority created by treaty licenses.

Water efficiency here means output obtained per unit of water consumed, so the least efficient crop is the one demanding the most water for its yield. Sugarcane is a long duration crop occupying the field for ten to eighteen months with continuously high evapotranspiration, requiring roughly 1500 to 2500 millimetres of water, which makes option (a) correct.

• Option (c) pearl millet is the opposite case, a hardy C4 dryland cereal grown in the arid Rajasthan and Gujarat belt on minimal rainfall.
• Option (d) red gram is a rainfed pulse with deep roots and low irrigation demand.
• Option (b) sunflower is moderate in requirement and is often grown as a short duration oilseed. Hence (a). The policy relevance is worth flagging in class: sugarcane's water intensity in Maharashtra and the assured price mechanism together produce one of the sharpest distortions in Indian cropping patterns.

Both statements follow from the same mechanism, wind driven surface circulation.

• Statement 1 is correct: the trade winds blow from east to west across the tropics, piling warm surface water against the western margins of ocean basins and producing the western boundary currents such as the Gulf Stream and Kuroshio, while the eastern margins experience compensating upwelling of cold water, as off Peru and Namibia. This is why the western tropical Pacific warm pool exists and why El Nino, which relaxes the trades, is so consequential.
• Statement 2 is correct: in the temperate belt the westerlies drive warm water eastward, so the North Atlantic Drift warms the eastern Atlantic and north western Europe, leaving the western sections at comparable latitudes colder, which is why Labrador is far colder than Britain. Hence (c). Teaching the gyre as a single closed circulation makes both statements fall out of one diagram.

The question tests the ranking of freshwater reservoirs. Of all water on Earth roughly 97 per cent is saline ocean and about 3 per cent fresh. Within that freshwater fraction, glaciers and polar ice hold approximately 68 to 69 per cent, groundwater approximately 30 per cent, and surface water in rivers and lakes barely 0.3 per cent.

• Statement 1 is therefore incorrect by a very wide margin, rivers and lakes holding far less than groundwater.
• Statement 2 is correct, ice exceeding groundwater. Hence (b). The ordering to memorise is ice, then groundwater, then surface water, and it explains why groundwater depletion is so consequential: it is the largest reservoir of fresh water actually accessible for human use.

Black cotton soil, or regur, is the weathering product of the Deccan basalts, erupted as flood basalts through fissures rather than central vents during the late Cretaceous, so option (b) is correct. The parent rock explains every property of the soil: it is rich in iron, magnesium, calcium and aluminium and poor in nitrogen and organic matter; it is clayey and montmorillonitic, so it swells when wet and develops deep cracks when dry, giving it self ploughing character and high moisture retention that suits cotton in a rainfed setting.

• Option (a) is wrong because brown forest soils are Himalayan.
• Option (c) is wrong because granite and schist weather to red and lateritic soils.
• Option (d) is wrong because shale and limestone give calcareous and alluvial derivatives. Hence (b). The geographical correspondence between the Deccan Trap outcrop and the regur belt of Maharashtra, Madhya Pradesh and Gujarat is the confirming check.

Lake Faguibine lies in northern Mali, in the Sahelian floodplain fed by the Niger through a system of channels near Timbuktu. Successive droughts from the early 1970s, compounded by reduced flood inflow and silting of the feeder channels, dried the lake, and its bed has since been colonised by sand and scrub, so that a formerly extensive water body now presents a desert landscape.

• Option (a) is wrong on location before anything else: Lake Victoria is in East Africa and remains the continent's largest lake by area.
• Option (c) is wrong because Lake Oguta, in Imo State in southeastern Nigeria, is a small natural lake that has not dried.
• Option (d) is wrong because Lake Volta in Ghana is not a natural lake at all but one of the world's largest reservoirs by surface area, impounded by the Akosombo Dam, and it holds water.

Hence (b).

The gorge at Gandikota lies in the Kadapa district of Andhra Pradesh, where the Pennar, or Penna, has incised a deep canyon through the quartzite of the Erramala hills, the feature that gives the site its popular description as the Grand Canyon of India and its name, which refers to the narrow gap beside the fort.

• Option (a) is wrong because the Cauvery rises in Karnataka and drains through Tamil Nadu to the Bay of Bengal well to the south, its notable gorge features being at Hogenakkal and Shivanasamudra.
• Option (b) is wrong because the Manjira is a tributary of the Godavari flowing through Telangana and does not reach the Kadapa region.
• Option (d) is wrong because the Tungabhadra, a Krishna tributary, flows to the north of this tract through the Hampi region.

Hence (c).

• Pair 1 is incorrectly matched. Namcha Barwa stands at the eastern extremity of the Himalaya in Tibet, marking the syntaxial bend where the Tsangpo turns south through its great gorge to become the Siang and then the Brahmaputra. It lies far to the east of the Garhwal Himalaya, which occupies the western part of Uttarakhand.
• Pair 2 is correctly matched. Nanda Devi, the highest peak lying wholly within India, is in the Kumaon Himalaya of eastern Uttarakhand and gives its name to the surrounding national park and biosphere reserve.
• Pair 3 is incorrectly matched. Nokrek is the highest point of the Garo Hills in Meghalaya, part of the Meghalaya plateau of the peninsular block, and is known chiefly as a biosphere reserve with wild citrus germplasm. It is neither in Sikkim nor in the Himalaya at all, which is the sharper error. Only pair 2 stands, giving (b); options (a) and (c) admit the misplaced Namcha Barwa, and (c) and (d) admit the misplaced Nokrek.

The Levant is the historic name for the lands along the eastern shore of the Mediterranean, covering Syria, Lebanon, Israel, Palestine, Jordan and the adjoining coastal fringe of southern Turkey, with Cyprus sometimes included. The name derives from the rising of the sun in the east, which is the sense in which the region was seen from western Europe.

• Option (a) states this and is correct.
• Option (b) describes the Maghreb, the western North African belt from Egypt through Libya, Tunisia, Algeria and Morocco, which lies on the opposite side of the Mediterranean basin.
• Option (c) conflates two distinct regions, the Persian Gulf littoral and the Horn of Africa, neither of which touches the Mediterranean at all.
• Option (d) is wrong by overextension: the Levant is one segment of the Mediterranean coast, not the whole of it, and taking the entire littoral would absorb southern Europe and North Africa into the term.

Hence (a).

Afghanistan's northern frontier is formed by three Central Asian republics. Tajikistan shares the longest of these borders, running largely along the Panj headwater of the Amu Darya. Uzbekistan shares a short border in the north, crossed by the Friendship Bridge at Termez and Hairatan. Turkmenistan borders Afghanistan in the north west. Country 1, Azerbaijan, lies in the South Caucasus, separated from Afghanistan by the Caspian Sea and the whole width of Turkmenistan or Iran, and shares no border with it. Country 2, Kyrgyzstan, lies to the north east beyond Tajikistan, and the intervening Tajik territory, including the Wakhan corridor arrangement, keeps the two apart.

• Items 3, 4 and 5 therefore qualify and (c) is correct.
• Options (a), (b) and (d) each admit Azerbaijan or Kyrgyzstan or both, and the Kyrgyzstan error is the more tempting because it is genuinely a Central Asian state.

Note first that the question asks how many pairs are not correctly matched, an inversion that costs candidates marks even when they know the geography.

• Pair 1 is wrongly matched: the Ghataprabha is a tributary of the Krishna and its reservoir lies in Karnataka, in Belagavi district, not in Telangana.
• Pair 2 is correctly matched: Gandhi Sagar is on the Chambal in Madhya Pradesh, the uppermost of the Chambal valley project dams.
• Pair 3 is wrongly matched: the Indira Sagar reservoir is on the Narmada in Khandwa district of Madhya Pradesh, and is among the largest reservoirs in the country by storage.
• Pair 4 is wrongly matched: the Maithon dam is on the Barakar, a tributary of the Damodar, within the Damodar Valley Corporation system, and lies in Jharkhand rather than Chhattisgarh. Three pairs are therefore incorrect, giving (c).
• Options (a) and (b) undercount, and (d) would require Gandhi Sagar to be misplaced as well.

The question turns on net cloud radiative forcing, which is the balance between a cloud's shortwave albedo effect and its longwave greenhouse effect.

• Statement 1 is incorrect. High clouds are cirriform, thin and composed of ice crystals, so they are largely transparent to incoming solar radiation and reflect comparatively little of it. Their tops are very cold, so they radiate to space at a much lower temperature than the surface whose outgoing longwave they intercept, and the resulting deficit in emission traps energy in the system. The net effect of high cloud is therefore warming, not cooling, and the statement reverses it.
• Statement 2 is incorrect as a whole, though its first clause is sound. Low clouds are optically thick and do behave almost as black bodies in the infrared, so they absorb the longwave radiation leaving the surface. But their tops are warm, being close to surface temperature, so they re-emit at nearly the same rate and their greenhouse effect is correspondingly small, while their high albedo reflects a large fraction of incoming solar radiation. The albedo term dominates, and the net effect of low cloud is cooling, so the conclusion drawn in the statement does not follow from its premise. Both statements failing, (d) is correct; options (a), (b) and (c) each accept one of the two reversed net effects.

• Statement 1 is incorrect on the country. Bidi Bidi lies in north western Uganda, in Yumbe district near the South Sudanese border, and it became one of the largest refugee settlements in the world after the influx that followed the resumption of civil war in South Sudan in 2016. The statement's placement of it in Kenya is the single error, and the question is constructed so that a candidate who knows only that Bidi Bidi is large and African will be caught by it.
• Statement 2 is correct, and it follows from the same facts: the settlement's population is overwhelmingly South Sudanese, displaced by that civil war.
• Statement 3 is correct. Dadaab, in eastern Kenya near the Somali border, was established in 1991 as Somalia collapsed and has housed Somali refugees ever since, remaining one of the largest such complexes anywhere.
• Statements 2 and 3 holding, (c) is correct.
• Option (a) accepts the misplacement of Bidi Bidi, option (b) drops the sound Dadaab statement, and option (d) drops the sound statement about who lives in Bidi Bidi.

• Statement 1 is incorrect as at the date of the examination. The largest solar park in India was the Bhadla Solar Park in Jodhpur district of Rajasthan, developed on land whose extreme aridity and high irradiance make it useless for almost anything else, and which was at the time among the largest such installations in the world.
• Statement 2 is correct. Cochin International Airport in Kerala became the first airport anywhere to run fully on solar power, with generation from installations around the airport including on rooftops and in an adjoining solar farm, work for which it received the United Nations Champions of the Earth award.
• Statement 3 is incorrect. The largest floating solar photovoltaic projects in India are on reservoirs in the Telangana and Andhra Pradesh region, the Ramagundam installation on a reservoir of the NTPC plant being the largest at the time; Goa hosts no project of that scale. Only statement 2 stands, giving (b), and options (a), (c) and (d) each accept a misattributed superlative.

• Pair 1 is correctly matched. Anatolia, or Asia Minor, is the great peninsula that forms the Asian portion of Turkey and the bulk of its territory.
• Pair 2 is correctly matched. Amhara is a region of Ethiopia, neighbouring Tigray, and was drawn into the war that began in that region.
• Pair 3 is incorrectly matched. Cabo Delgado is the northernmost province of Mozambique, in the news for an Islamist insurgency that displaced hundreds of thousands and disrupted a major offshore gas development; the Portuguese name is what makes Spain a plausible looking distractor.
• Pair 4 is incorrectly matched. Catalonia is in Spain, not Italy, with Barcelona as its capital and an independence movement that has long strained Spanish politics. Exactly two pairs are correct, giving (b). The question is well constructed in that the two errors are paired: a candidate who knows Catalonia is Spanish is invited to attach Spain to Cabo Delgado, and options (a), (c) and (d) each depend on one of these confusions.

• Statement 1 is correct. The Jhelum flows into and out of Wular Lake in Kashmir, which acts as a natural flood absorption basin for the river.
• Statement 2 is incorrect. Kolleru Lake lies between the Krishna and Godavari deltas and is fed principally by the Budameru and Tammileru streams, with only seasonal spill connection to the deltas. The Krishna does not directly feed it.
• Statement 3 is the decisive one. Kanwar Taal, also written Kabartal, in Begusarai district of Bihar is an oxbow lake formed by the meandering of the Burhi Gandak, which is a separate river from the Gandak. On that reading only statement 1 is correct, giving (a).
• Option (b) would follow if the examiner treated Gandak and Burhi Gandak as interchangeable, (c) is ruled out by the Kolleru error, and (d) is ruled out because the Jhelum and Wular relationship is textbook.

• Pair 1 is correct. Kamarajar Port, formerly Ennore, was the first major port in India to be incorporated as a company under the Companies Act rather than run by a Port Trust.
• Pair 2 is correct. Mundra in Gujarat, operated by Adani Ports, is the largest privately owned and largest overall cargo handling port in the country.
• Pair 3 is incorrect. The largest container handling port in India is Jawaharlal Nehru Port, Nhava Sheva, not Visakhapatnam, which is a large bulk and general cargo port. Two pairs therefore match, giving (b).
• Option (a) understates, (c) requires the container claim to be true, and (d) is ruled out by the two clearly correct pairs.

• Statement 1 is correct. India has roughly 155 to 160 million hectares of arable land against about 120 million hectares in China, a consequence of India's much larger share of cultivable plain relative to its total area, while a large part of China is desert, plateau and mountain.
• Statement 2 is incorrect. China irrigates a higher share of its cultivated area than India does, in the region of half or more against India's figure of around 45 to 50 per cent.
• Statement 3 is incorrect. Chinese yields per hectare exceed Indian yields across most major crops, notably rice, wheat and cotton, on account of higher fertiliser and mechanisation intensity and better assured irrigation. Only statement 1 stands, giving (a).
• Options (b) and (c) require the irrigation or yield claim to hold, and (d) is ruled out by the arable area comparison.

• Statement 1 is incorrect. Amarkantak in Madhya Pradesh lies where the Vindhya, Satpura and Maikal ranges meet, and is the source region of the Narmada and Son. The Sahyadri is the Western Ghats and is nowhere near it.
• Statement 2 is incorrect. The Biligirirangan Hills lie in southern Karnataka and form a link between the Western Ghats and the Eastern Ghats, not any part of the Satpura, which is a central Indian range.
• Statement 3 is incorrect. The Seshachalam Hills are in Andhra Pradesh and belong to the Eastern Ghats, and are known for red sanders. The southernmost extent of the Western Ghats is around the Agasthyamalai and the Cardamom Hills. All three fail, giving (d). Any of (a), (b) or (c) would require at least one of these misplacements to be accepted.

• Statement 1 is incorrect on two counts. The East West Corridor is part of the North South and East West Corridor component of the National Highways Development Project, which is distinct from the Golden Quadrilateral, and it runs from Silchar to Porbandar, not Dibrugarh to Surat.
• Statement 2 is incorrect. The India Myanmar Thailand Trilateral Highway runs from Moreh in Manipur through Myanmar to Mae Sot in Thailand, not Chiang Mai.
• Statement 3 is incorrect. The BCIM Economic Corridor was conceived to link Kolkata with Kunming through Bangladesh and Myanmar, and Varanasi has no part in its alignment. All three fail, giving (d). The other options each require one of these three misdescriptions to pass.

• Option (c) is correct. Water vapour is the dominant absorber of infrared radiation in the atmosphere, with strong absorption bands in the infrared, and it is concentrated in the lower troposphere because its concentration falls steeply with temperature and hence with altitude. This is the physical basis of the natural greenhouse effect and of why humid nights cool less than dry ones.
• Option (a) is wrong on magnitude. Annual insolation at the equator exceeds that at the poles by a factor of roughly two and a half, not ten, since the poles receive continuous summer daylight which partly compensates for the very low solar elevation.
• Option (b) is wrong. Infrared accounts for roughly half of incoming solar energy, with visible light around forty per cent and ultraviolet under ten per cent, so two thirds overstates it.
• Option (d) is wrong by definition, infrared lying beyond the red end of the visible spectrum at longer wavelengths and therefore outside it.

• Statement II is correct and is elementary. The specific heat capacity of water is roughly four to five times that of dry soil and rock, and water is further moderated by vertical mixing, transparency to solar radiation and evaporative cooling, so oceans heat and cool far more slowly than land.
• Statement I is incorrect, and this is the harder judgement. The land and sea thermal contrast in the middle and higher latitudes is greatest in winter, not summer, because continental interiors cool dramatically under long nights, snow cover and radiative loss, reaching values tens of degrees below the adjacent ocean, whereas in summer land warms above the ocean by a much smaller margin. The strength of the winter Siberian high against the relatively mild North Atlantic and North Pacific illustrates the point.
• Statement I false and Statement II true gives (d).
• Options (a) and (b) require the summer contrast to dominate, and (c) denies a settled physical property.

Both statements are correct.

• Statement 1 follows from the fact that P waves are the faster body waves, travelling at roughly six kilometres per second in the crust against about three and a half for S waves, so they arrive first, which is why they are called primary waves. The widening gap between the P and S arrivals with distance is used to locate the epicentre and is the basis of early warning systems.
• Statement 2 states the physical distinction correctly. P waves are longitudinal or compressional, with particle motion parallel to the direction of propagation through alternating compression and rarefaction, and they therefore propagate through solids, liquids and gases. S waves are transverse, with particle motion perpendicular to propagation, which requires shear rigidity and is why they cannot travel through the liquid outer core, producing the S wave shadow zone.

Hence (c).

All three statements are absolute negatives and each falls to a single counter example.

• Statement 1 is incorrect, since coastal thermal stations such as those in Tamil Nadu, Gujarat and Andhra Pradesh use seawater for once through condenser cooling, which is one of the reasons imported coal plants are sited on the coast.
• Statement 2 is incorrect, and this is a well documented concern: a substantial share of India's coal fleet sits in water stressed districts of Maharashtra, Telangana, Madhya Pradesh and Chhattisgarh, and plants have repeatedly shut down for want of cooling water.
• Statement 3 is incorrect, private ownership being substantial through Tata Power, Adani Power, JSW and others, alongside NTPC and State generating companies. None stands, giving (d). The sweeping word none in each statement is itself the strongest clue at the exam.

• Statement I is correct. India is the largest extractor of groundwater in the world, accounting for roughly a quarter or more of global withdrawal, more than the United States and China combined.
• Statement II is incorrect, and the error is in the stated purpose rather than in the quantity. Around eighty to ninety per cent of India's groundwater extraction goes to irrigation, not to drinking water and sanitation, a pattern driven by tubewell expansion, subsidised or free power for pumping and the cropping choices encouraged by procurement. Domestic and industrial use together account for a small fraction. The scale of extraction is therefore explained by agriculture, and the drinking water justification offered in Statement II does not hold.
• Statement I correct and Statement II false gives (c).
• Options (a) and (b) require the domestic use explanation to be accepted, and (d) denies the reported extraction share.

• Statement-I is incorrect. The atmosphere is largely transparent to incoming short wave solar radiation, which passes through and heats the earth's surface. The atmosphere is then heated chiefly from below by outgoing long wave terrestrial radiation, through absorption, conduction and convection.
• Statement-II is correct. Carbon dioxide, water vapour, methane and other greenhouse gases absorb strongly in the infrared and are therefore good absorbers of long wave radiation, which is precisely the mechanism by which terrestrial radiation heats the atmosphere. Since Statement-I is false and Statement-II is true, (d) is correct.
• Options (a) and (b) both require Statement-I to be true and fail immediately.
• Option (c) inverts the truth values and fails on both counts. Note that Statement-II, correctly read, is the reason Statement-I is wrong.

• Statement-I is correct. The troposphere extends to roughly 18 km at the equator against roughly 8 km at the poles.
• Statement-II is correct. Intense insolation at the equator drives strong convection which carries heat, moisture and turbulence to great heights, pushing the tropopause upward.
• Statement-II is the causal explanation for Statement-I, so (a) is correct.
• Option (b) fails because the explanatory link is genuine and is the standard textbook reason.
• Options (c) and (d) fail because both statements are true.

• Statement 1 is correct. In January, the northern hemisphere winter, oceans retain heat while continents cool rapidly. Isotherms therefore bend poleward, that is northward, over the warmer oceans and equatorward, that is southward, over the colder land masses.
• Statement 2 is incorrect and internally contradictory. The Gulf Stream and North Atlantic Drift are warm currents, not cold, and they make the North Atlantic warmer rather than colder. Describing them as cold currents that produce cooling is a factual error, even though the concluding clause about isotherms bending north is itself true. A statement containing a false premise cannot be accepted. Hence (a).
• Options (b) and (c) require statement 2 to be true, and (d) wrongly rejects statement 1.

Cote d'Ivoire and Ghana are the world's two largest cocoa producers, together accounting for roughly sixty per cent of global output. Both lie in the humid tropical belt of West Africa with high rainfall, uniform high temperature and forest soils suited to the cocoa tree.

• Option (a) is wrong because Algeria and Morocco are North African Mediterranean and desert economies where cocoa cannot grow.
• Option (b) is wrong because Botswana and Namibia are arid to semi arid southern African states dominated by the Kalahari and Namib.
• Option (d) is wrong because Madagascar and Mozambique produce cocoa only marginally, and are better known for vanilla and cashew respectively.

Moving downstream from Prayagraj, that is west to east, the confluences occur in this order. The Gomati joins the Ganga near Saidpur in Ghazipur district of Uttar Pradesh. The Ghaghara joins further east near Chhapra in Bihar. The Gandak joins at Patna. The Kosi joins furthest east near Kursela in Katihar district. Hence Gomati, Ghaghara, Gandak, Kosi, which is (b).

• Options (a) and (c) place the Ghaghara before the Gomati, which reverses the true order since the Gomati confluence lies upstream.
• Options (c) and (d) place the Kosi before the Gandak, which is wrong because the Kosi is the easternmost of the four. Note that the Gomati is strictly a Himalayan foothill river rising from the Fulhaar jheel, which the question treats as Himalayan.

• Statement-II is correct. Atmospheric carbon dioxide dissolves in rain water to form carbonic acid, which drives carbonation, the chemical weathering process that dissolves limestone and decomposes feldspar.
• Statement-III is correct. Rain water carries dissolved atmospheric oxygen, which drives oxidation, the weathering process that converts ferrous minerals to ferric oxides and produces the reddish crusts and crumbling seen in iron rich rocks. Both processes are recognised forms of chemical weathering, so both statements explain Statement-I, giving (a).
• Option (b) fails because there is no basis for excluding either process.
• Option (c) fails because both statements are true, not one.
• Option (d) fails because both statements are factually correct.

Donyi Polo Airport at Hollongi near Itanagar in Arunachal Pradesh is a greenfield airport built on a fresh site and commissioned in 2022. Kushinagar International Airport in Uttar Pradesh was also developed as a greenfield project and commissioned in 2021, serving the Buddhist circuit. Vijayawada International Airport is not greenfield. It is the upgraded and expanded existing airport at Gannavaram, which has operated since well before the recent expansion, making it a brownfield development. Hence 1 and 2 only, which is (a).

• Option (b) wrongly includes Vijayawada and drops Donyi Polo.
• Option (c) makes the same Vijayawada error.
• Option (d) treats all three as greenfield and ignores the brownfield character of Gannavaram.

• Statement 1 is correct. Water vapour is concentrated in the lower troposphere and its quantity falls sharply with height, with about half of all atmospheric water vapour lying below roughly 2 km and almost none above 12 km.
• Statement 2 is incorrect. Water vapour content is maximum over the warm humid equatorial and tropical oceans, where it can reach about four per cent of air by volume, and minimum over the cold polar regions, where it falls to a fraction of one per cent. The saturation capacity of air rises with temperature, so cold polar air simply cannot hold much vapour. Hence (a).
• Options (b) and (c) require the false polar claim, and (d) wrongly rejects the correct altitude relationship.

Total fertility rate is the average number of live births a woman would have if she survived through and experienced the prevailing age specific fertility rates across her entire reproductive span, conventionally ages fifteen to forty nine. This is precisely option (d).

• Option (a) defines the crude birth rate, which is expressed per thousand population and not per woman.
• Option (b) is close but wrong on two counts. It refers to a couple rather than a woman and describes actual completed family size rather than the synthetic cohort measure that TFR is, since TFR is computed from current age specific rates rather than observed lifetime outcomes.
• Option (c) defines the rate of natural increase. The replacement level TFR of about 2.1 and India's decline to 2.0 in NFHS-5 rest on definition (d).

The Canada United States border is the longest international boundary in the world at roughly 8891 kilometres, including the Alaska Yukon and Alaska British Columbia sections, and it is also the longest undefended border.

• Option (d) is the closest competitor and the intended trap, since the Kazakhstan Russia border at about 7644 kilometres is the longest continuous land border without a maritime interruption, but it is still shorter overall.
• Option (b) is wrong because the Chile Argentina border along the Andes runs to about 5300 kilometres, long but well short of the leaders.
• Option (c) is wrong because the disputed China India boundary is roughly 3488 kilometres by the Indian reckoning, not remotely in contention. A candidate who recalls only that the answer is a very long northern hemisphere boundary must still separate Canada United States from Kazakhstan Russia, which is what the question is testing.

• Statement-II is correct. The Suez Mediterranean pipeline runs from Ain Sukhna on the Gulf of Suez, an arm of the Red Sea, to Sidi Kerir near Alexandria on the Mediterranean.
• Statement-I is correct in the sense intended. The pipeline is a strategic alternative and complement to the Suez Canal, allowing cargo to be offloaded, piped across Egypt and reloaded, which both bypasses draught limits on the largest tankers and provides redundancy if the canal is blocked.
• Statement-II supplies the reason for Statement-I, since it is exactly the Red Sea to Mediterranean connection that makes the pipeline a route from the Gulf to Europe, so (a) follows.
• Option (b) fails because the explanatory link is direct.
• Options (c) and (d) fail because both statements are accepted as correct.

Both statements are correct and together explain why the Red Sea is among the most saline open seas in the world, with salinity around 40 parts per thousand.

• Statement 1 holds because the Red Sea lies within the subtropical high pressure belt, flanked by the Sahara and the Arabian deserts, and receives negligible rainfall, of the order of a few centimetres a year.
• Statement 2 holds because no perennial river drains into the Red Sea. Its catchment is desert, and such wadis as exist flow only briefly after rare storms. With high evaporation under intense insolation, no riverine inflow and almost no precipitation, the water balance is maintained chiefly by inflow from the Gulf of Aden through the Bab el Mandeb, and the deficit drives the high salinity.

Hence (c), and options (a), (b) and (d) each reject a correct statement.

• Statement I is correct: India was admitted to the Minerals Security Partnership, the US-led plurilateral aimed at securing resilient critical mineral supply chains, in 2023.
• Statement II is incorrect and is the decisive elimination. The Ministry of Mines identified 30 critical minerals precisely because India is import-dependent or resource-deficient in most of them, including lithium, cobalt, nickel, germanium and the heavy rare earths. Identifying a mineral as critical is an admission of vulnerability, not of endowment, so the word all makes the statement self-defeating.
• Statement III is correct: the MMDR Amendment Act, 2023 inserted a list of critical and strategic minerals in Part D of the First Schedule and reserved to the Central Government the power to auction mining leases and composite licences for them, while royalty continues to accrue to the States. Since only I and III stand, the answer is (c).
• Options (a), (b) and (d) all require Statement II, which cannot survive the logic of the critical minerals list itself. A candidate who understood why the list was drawn up could eliminate three options without knowing either of the other two facts.

• Statement I is correct. India accounts for the dominant share of world turmeric production, commonly cited at around seventy to eighty per cent, and is simultaneously the largest exporter and the largest consumer, with major export destinations including Bangladesh, the UAE, the United States and Malaysia.
• Statement II is correct. More than thirty varieties of turmeric are grown across some twenty states, differing in curcumin content, duration and rhizome character, with well-known regional types including Lakadong, Alleppey Finger, Erode and Rajapuri.
• Statement III is correct. Maharashtra, Telangana, Karnataka and Tamil Nadu are among the leading producing states, along with Andhra Pradesh, Odisha and West Bengal. All three statements therefore hold, giving (d).
• Options (a), (b) and (c) each drop one accurate statement. The question sits close to a news trigger, since the National Turmeric Board was constituted in 2023 to support production, value addition and export promotion, though the content tested is standard agricultural geography rather than the Board itself.

All three are among the classic evidences Wegener and his successors advanced for continental drift, and all three appear in the standard treatment in the NCERT physical geography text, giving (c).

• Statement I is the argument from rock and structural continuity: a belt of ancient rocks of comparable age and composition runs along the Brazilian coast and reappears on the coast of western Africa, which is difficult to explain unless the two margins were once joined.
• Statement II is the placer gold argument: the gold-bearing deposits of the Ghana coast lack a corresponding source rock nearby, while the Brazilian plateau supplies a plausible parent, implying juxtaposition of the two landmasses at the time of deposition.
• Statement III is the argument from the Gondwana sediments: the sequence found in peninsular India, characterised by tillite at its base indicating glaciation, has counterparts across Africa, Madagascar, Australia, Antarctica, the Falklands and South America, pointing to a single former supercontinent.
• Options (a), (b) and (d) each omit one of the three, and none of the statements contains an error that would justify its exclusion.

• Statement I is correct and reproduces the standard textbook position: dust concentration is highest over subtropical and temperate latitudes and lowest over equatorial and polar regions.
• Statement II is incorrect, and it inverts the very reason Statement I holds. Subtropical and temperate areas have more dry winds, not less. The subtropical belt is dominated by descending limbs of the Hadley circulation, producing arid and semi-arid surfaces with sparse vegetation cover from which fine particles are readily lifted. By contrast the equatorial belt has heavy convectional rainfall, dense vegetation and high humidity, so particles are both less available and continuously scavenged from the air by precipitation, while polar regions have frozen or snow-covered surfaces offering little loose material. Since I holds and II fails, the answer is (c).
• Options (a) and (b) both require Statement II to be correct.
• Option (d) rejects the dust distribution itself, which is well established. The trap rewards a candidate who notices that the given explanation contradicts rather than supports the observation.

January is winter in the Northern Hemisphere.

• Statement II is correct because of the differential heating and cooling of land and water: land has low specific heat and heats and cools rapidly, while water has high specific heat, mixes vertically and is partly transparent to insolation, so it retains heat far longer. In winter the continents therefore cool sharply while the adjacent oceans remain relatively warm.
• Statement I is correct and follows directly. An isotherm joins points of equal temperature, so where it crosses a cold landmass it must swing towards the equator to find that temperature, and where it crosses a warmer ocean it swings towards the pole. The bending is thus a map expression of the land and sea contrast, which means Statement II genuinely explains Statement I, giving (a).
• Option (b) concedes both statements but denies the causal link, which cannot stand since the temperature contrast is the sole cause of the deflection.
• Options (c) and (d) each reject one correct statement. Note that in July the pattern reverses, with isotherms bending poleward over the heated landmasses.

This question turns entirely on the distinction between porosity and permeability, and rewards the candidate who holds the two apart. Porosity is the proportion of void space in a rock; permeability is the ability of fluid to pass through it, which depends on whether those voids are large and interconnected.

• Statement I is correct: chalk is a highly permeable rock and forms important aquifers, while clay is the classic aquiclude.
• Statement II is correct: chalk is porous, with well-connected pore spaces and fissures that both hold and transmit water, and this explains the permeability asserted in Statement I.
• Statement III is incorrect, and this is the decisive point. Clay is in fact highly porous, often with porosity of forty to fifty per cent, which is comparable to or greater than many permeable rocks. It is impermeable not because it lacks voids but because its pores are extremely fine and poorly connected, so capillary and surface tension forces hold water in place rather than transmitting it. Only Statement II is correct and it does explain Statement I, giving (c).
• Options (a) and (b) both require Statement III to stand, and option (d) wrongly rejects the porosity of chalk.

• Statement I is correct. Balancing absorbed solar radiation against emitted longwave radiation gives Earth an effective radiating temperature of about minus eighteen degrees Celsius, well below freezing. The observed global mean of roughly fifteen degrees Celsius is the difference made by the atmosphere, so without it the surface would indeed be frozen almost everywhere.
• Statement II is correct and states the mechanism: the atmosphere is largely transparent to incoming shortwave solar radiation but absorbs a substantial part of the outgoing longwave terrestrial radiation, re-emitting it in all directions including downward, which raises the equilibrium surface temperature.
• Statement III is correct. Molecular structure decides radiative behaviour. Nitrogen and oxygen, being homonuclear diatomic molecules with no dipole moment, are effectively transparent to longwave radiation, whereas carbon dioxide, water vapour, methane and nitrous oxide possess vibrational modes that produce a changing dipole moment and therefore absorb strongly in the infrared. All three hold, giving (c).
• Options (a), (b) and (d) each omit one correct statement. Note that the question describes the natural greenhouse effect, which makes the planet habitable, and not the enhanced anthropogenic effect.

• Statement I is correct: polar motion, the wandering of the rotation axis relative to the crust, is measured continuously, and published work attributes a significant part of the recent drift, along with a lengthening of the day, to redistribution of mass at the surface.
• Statement II is correct as a standalone fact: solar flares and coronal mass ejections do deposit very large amounts of energy in the outermost atmosphere, heating and expanding the thermosphere, driving geomagnetic storms and increasing satellite drag.
• Statement III is correct: meltwater from the polar ice sheets does not stay at high latitudes but is redistributed through the oceans, with a net transfer of mass towards lower latitudes. The discriminating step is the explanatory link. Moving mass from the poles towards the equator increases the Earth's moment of inertia about the rotation axis and alters the mass distribution relative to that axis, which by conservation of angular momentum slows the rotation slightly and shifts the pole.
• Statement III therefore explains Statement I.
• Statement II does not: solar energy input affects the upper atmosphere and the magnetosphere, but is far too small and too external to move the rotation axis of a body of the Earth's mass. Both are correct, only one explains, giving (b).
• Option (a) wrongly admits the solar link, option (c) requires one statement to be false, and option (d) rejects both.

• Statement I is incorrect, and the ranking is the reverse of what is asserted. The United States is the world's largest producer of fuel ethanol, accounting for roughly half of global output, with Brazil second at somewhere near a quarter to a third. Brazil has the longer history, having built its Proalcool programme after the oil shocks of the nineteen seventies and pioneered flex fuel vehicles, and this priority in time is very likely the source of the mistaken belief that it leads in volume.
• Statement II is correct. The United States relies overwhelmingly on corn, converting starch to fermentable sugars through enzymatic hydrolysis, whereas Brazil uses sugarcane, whose sucrose is directly fermentable and whose bagasse can be burnt to power the mill, giving the Brazilian route a considerably better energy balance and lower cost per litre. Since I fails and II holds, the answer is (d).
• Options (a) and (b) both require the production ranking to be correct.
• Option (c) inverts the position entirely, accepting the false ranking while rejecting the well-established feedstock difference.

The two places sit on opposite sides of the International Date Line, which runs roughly along the one hundred and eightieth meridian through the Bering Strait, deviating to keep territories whole.

• Statement I is correct: despite their proximity across the strait, Anadyr on the Russian side and Nome on the Alaskan side lie in different calendar days, since crossing the Date Line changes the date by one day irrespective of the small difference in longitude. This is the standard illustration of the Date Line's effect.
• Statement II is incorrect, and it reverses the direction. Anadyr lies west of the Date Line on the Asian side and is therefore ahead in date, at about UTC plus twelve, while Nome lies east of it on the American side and is behind, at about UTC minus nine. So when it is Monday in Anadyr it is Sunday in Nome, not Tuesday. The reliable rule is that travelling westward across the Date Line advances the date and travelling eastward sets it back, so the Asian side is always the later date. Only I holds, giving (a).
• Options (b) and (c) accept the reversed direction, and option (d) denies the date change altogether.

Only item 3 can serve as a basis, so (d) is correct. Freshwater river dolphins of the genus Platanista occur as closely related populations in both the Indus system and the Ganga system, and since these animals cannot cross salt water or watersheds, a shared ancestry implies that the two systems were once physically connected. That biogeographic argument is precisely the kind of independent evidence a Pleistocene drainage rearrangement requires.

• Item 1 fails on chronology, because the Nadi Sukta is a Rigvedic hymn of the second millennium BCE that lists rivers of the period and can bear on Holocene channel changes such as the Sarasvati question, but it cannot testify to the Pleistocene, which ended more than ten thousand years earlier.
• Item 2 fails on fact, since Robert Bruce Foote's field work is associated with prehistoric stone tool discoveries in peninsular India, notably at Pallavaram, rather than with a survey of Sutlej and Yamuna palaeochannels. (a), (b) and (c) all rest on one or both of these unsound items.

Only statement 3 is correct, so (d) is the answer. Vizhinjam has a natural draft of about eighteen to twenty metres within a very short distance of the shore and lies roughly ten nautical miles from the main east west shipping lane, which together allow it to receive the largest container vessels without heavy dredging. Its purpose is to capture the Indian transshipment cargo that has historically been handled at Colombo, Singapore and Jebel Ali, which is what is meant by reducing dependence on foreign transshipment ports and retaining the associated revenue.

• Statement 1 is wrong on both limbs, because the port is designed as an international transshipment hub rather than an exclusively domestic one, and it was built under a public private partnership with foreign supplied equipment, so it neither eliminates nor was intended to eliminate foreign collaboration.
• Statement 2 is wrong because cruise and heritage tourism is at most an incidental function, and the port's design, cranes and yard capacity are container oriented.
• Options (a), (b) and (c) each rest on one of these mischaracterisations.

The question asks which statements are not correct, so the answer names the errors.

• Statement 1 is correct and is therefore not part of the answer, since Uttar Pradesh touches eight States, namely Uttarakhand, Himachal Pradesh, Haryana, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand and Bihar, besides the National Capital Territory, which is more than any other State, Assam coming next with seven.
• Statement 2 is not correct, because the longest international boundary of any Indian State belongs to West Bengal, which faces Bangladesh over roughly two thousand two hundred kilometres besides short stretches with Nepal and Bhutan, while Rajasthan's boundary with Pakistan is only about one thousand and seventy kilometres.
• Statement 3 is not correct, because Sikkim touches only West Bengal but is not unique in that respect, since Meghalaya touches only Assam. Hence 2 and 3 are the incorrect statements and (c) is right. (a) and (b) wrongly treat the accurate Uttar Pradesh claim as an error, and (d) misses the Rajasthan error.

• Statement 1 is correct, since the islands lie between about six and fourteen degrees north in the Bay of Bengal, with a small land area surrounded by warm sea, giving high humidity, a very small annual range of temperature and heavy rainfall, which is the definition of a humid tropical coastal or equatorial maritime climate.
• Statement 2 is correct, and it follows from position rather than memory. The islands lie in the path of the Bay of Bengal branch of the southwest monsoon from May onward and again in the path of the retreating northeast monsoon from October to December, when those winds pick up moisture crossing the Bay.
• Statement 3 is incorrect and is the eliminator, because it inverts the wet season. The islands are wet from roughly May to December and comparatively dry from January to April, so a December to May maximum is wrong at both ends.

Hence 1 and 2 and (b) is correct, while (c) and (d) accept the inverted rainfall regime and (a) discards a statement that follows directly from the islands' latitude and position.

• Statement 1 is correct, since the western coast of the Peninsula is a faulted and submerged coast produced when a block west of the Western Ghats foundered along the Western Ghat fault, which is why that coast is narrow, has drowned river mouths and lacks a wide depositional plain, unlike the emergent eastern coast.
• Statement 2 is correct, because the Veliconda and Mahendragiri hills are discontinuous residual ranges of the Eastern Ghats, the worn down stumps of a very old orogeny, and residual relief is a defining mark of a stable ancient block.
• Statement 3 is incorrect and is the eliminator, since deep V shaped gorges cut by swift rivers are the signature of the young, still rising Himalaya, whose rivers have high vertical erosive power. Peninsular rivers flow over a block that has been stable for a very long time, have graded profiles close to base level and occupy broad shallow mature valleys, the Narmada and Tapi rift valleys being structural rather than erosional exceptions.

Hence 1 and 2 and (b) is correct, while (c) and (d) transfer a Himalayan characteristic to the Peninsula.

• Statement 1 is correct, since Lake Turkana is the largest permanent desert lake and the largest alkaline lake in the world, fed mainly by the Omo river and having no outlet, so that it loses water only by evaporation.
• Statement 2 is incorrect and is the eliminator on two separate counts. The lake lies in northern Kenya with its northern tip extending into Ethiopia, not in South Sudan, and it occupies a basin of the Great Rift Valley in East Africa, which is thousands of kilometres from the Sahara.
• Statement 3 is correct, since the Lake Turkana National Parks are inscribed on the World Heritage List, partly for the hominin fossil record of Koobi Fora, and the lake is popularly called the Jade Sea from the blue green colour imparted by algae.

Hence 1 and 3 and (b) is correct, while (c) and (d) accept the misplacement of the lake and (a) drops the World Heritage and Jade Sea facts.

Only statement 3 is correct, so (d) is the answer. The Mechi bridge over the Mechi river links the Panitanki bypass on the Indian side in West Bengal with Kakarvitta in Nepal, and it lies on the Asian Highway corridor.

• Statement 1 reverses the two ends. Maitri Setu does span the Feni river, but Sabroom is the Indian town in South Tripura and Ramgarh is on the Bangladesh side in Chittagong division, so the statement has placed each town in the wrong country.
• Statement 2 misidentifies the neighbour, since the Jhulaghat suspension bridge crosses the Kali or Mahakali river and connects Pithoragarh district of Uttarakhand with the Baitadi district of Nepal, and India shares no bridge of that name with Myanmar. (a) and (c) accept the reversed Maitri Setu description and (a) and (b) accept the Myanmar error.

• Statement 1 is correct and statement 2 is the eliminator, so (a) is the answer. The Bharat Forecast System is a high resolution numerical weather prediction model working on a grid of about six kilometres against the roughly twelve kilometre grid of the system it replaces, and that refinement is precisely what allows forecasts to be issued for panchayat clusters rather than for districts, which is the operational point for agriculture and for local disaster response.
• Statement 2 misattributes the development. The model was built by the Indian Institute of Tropical Meteorology at Pune, an institution of the Ministry of Earth Sciences, and it runs on the Arka high performance computing system, with the India Meteorological Department operationalising the forecasts. The Indian Institutes of Technology contribute to atmospheric research but are not the developers of this model. (b) and (c) accept the misattribution and (d) discards the accurate statement of purpose.