Geography

Correct answer: (D) Statement-I is incorrect, but Statement-II is correct

Statement-I is incorrect: the atmosphere is heated mainly by terrestrial (long-wave) radiation, not directly by incoming solar (short-wave) radiation. Most incoming solar radiation passes through the atmosphere and heats the Earth's surface, which then re-radiates heat as long-wave radiation that the air absorbs. Statement-II is correct because CO2 and other greenhouse gases are good absorbers of long-wave (terrestrial) radiation, which is exactly why the surface, and not incoming sunlight, warms the air. Hence only Statement-II is correct, giving option D.

Correct answer: (A) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I

Both statements are correct and the second explains the first. The troposphere is about 16-18 km thick at the equator but only around 8-9 km at the poles. This is because intense equatorial heating drives strong convection currents that carry heat and turbulence to greater heights, pushing the tropopause higher. So Statement-II is the direct cause of Statement-I, making option A correct.

Correct answer: (D) All four

All four are products of volcanic eruptions. Eruptions eject pyroclastic debris (rock fragments/bombs), fine ash and dust, and release gases including sulphur compounds (mainly SO2 and H2S) and nitrogen compounds. Volcanic gases are dominated by water vapour, CO2 and sulphur, but nitrogen and its compounds are also emitted, so the count is all four, giving option D.

Correct answer: (A) 1 only

Only inference 1 is correct. In January (Northern winter) the oceans are warmer than the cold continents, so isotherms bend north (poleward) over oceans and south (equatorward) over continents, confirming statement 1. Statement 2 is wrong on two counts: the Gulf Stream and North Atlantic Drift are warm currents (not cold), and they make the North Atlantic warmer, causing isotherms to bend north over that ocean because of warmth, not cold. Hence only 1 is correct, giving option A.

Correct answer: (C) Côte d'Ivoire and Ghana

Cote d'Ivoire (Ivory Coast) and Ghana are the world's two largest cocoa producers, together accounting for roughly 60% of global cocoa output. Both are West African nations with climates ideal for cacao cultivation. The other pairs (North African, southern African and Indian Ocean countries) are not major cocoa producers, so option C is correct.

Correct answer: (B) Gomati – Ghaghara – Gandak – Kosi

Moving downstream of Prayagraj (Allahabad) from west to east, the Himalayan tributaries join the Ganga in the order Gomati, Ghaghara, Gandak, Kosi. The Gomati joins first near Ghazipur/Saidpur, followed by the Ghaghara, then the Gandak near Patna, and finally the Kosi in Bihar before the river enters West Bengal. This west-to-east sequence matches option B.

Correct answer: (A) Both Statement-II and Statement-III are correct and both of them explain Statement-I

All three statements are correct and both II and III explain I. Rainfall causes chemical weathering: rain water dissolves atmospheric CO2 to form weak carbonic acid, which chemically attacks rocks (carbonation), and it also carries dissolved atmospheric oxygen that drives oxidation of minerals like iron. Thus both the CO2 content (Statement-II) and the oxygen content (Statement-III) explain why rainfall weathers rocks, making option A correct.

Correct answer: (B) Only two

Only two of the listed countries border the North Sea: Germany and Norway. Finland borders the Baltic Sea and Gulf of Bothnia, not the North Sea, and Russia's western coast is on the Baltic (and its north on the Arctic), not the North Sea. The North Sea is bordered by Britain, Norway, Denmark, Germany, the Netherlands, Belgium and France, so the count is two, giving option B.

Correct answer: (A) Only one

Only one row is correctly matched. Dhuandhar falls is on the Narmada, but it lies in the Bhedaghat/Jabalpur area on the Deccan/Vindhya edge, not the Malwa region, so that row is wrong. Hundru falls is correctly on the Subarnarekha river in the Chota Nagpur plateau, so that row is right. Gersoppa (Jog) falls is on the Sharavati river, not the Netravati, so that row is wrong. Only the Hundru row matches, giving option A.

Correct answer: (B) Only two

Only two rows are correctly matched. The Vosges are in Europe (France), not Central Asia, and are block/relict mountains, so that row is wrong. The Alps are fold mountains, not block mountains, so the Alps row is also wrong. The Appalachians (North America) and the Andes (South America) are both correctly identified as fold mountains. Thus exactly two rows are correct, giving option B.

Correct answer: (A) 1 only

Only statement 1 is correct. Water vapour is a gas whose concentration decreases with altitude, since most of it is concentrated in the lower troposphere near evaporating surfaces. Statement 2 is wrong: water vapour percentage is maximum over warm, humid equatorial/tropical regions and least at the cold, dry poles, because warm air holds far more moisture. So only 1 is correct, giving option A.

Correct answer: (D) Marine West coast climate

The description points to the Marine West Coast (temperate oceanic) climate. Its hallmark is a low annual and daily temperature range due to the moderating influence of the sea, precipitation spread throughout the year (no dry season) brought by westerlies, and moderate rainfall roughly in the 50-250 cm range. Equatorial climate has much heavier rainfall and China-type has a distinct seasonal (monsoonal) rhythm, so option D is correct.

Correct answer: (C) Both 1 and 2

Both statements about the Coriolis force are correct. The Coriolis force is directly proportional to wind velocity, so it increases as wind speed increases (statement 1). It also varies with latitude, being zero at the equator and maximum at the poles because it depends on the sine of the latitude (statement 2). Both are true, giving option C.

Correct answer: (D) 2 and 4

On June 21 (summer solstice), the Sun is overhead at the Tropic of Cancer and the Northern Hemisphere is tilted toward the Sun. So the Tropic of Cancer (2) and the Arctic Circle (4) both get more than 12 hours of daylight, the Arctic Circle even experiencing a 24-hour day. The equator always has about 12 hours, and the Tropic of Capricorn (Southern Hemisphere) gets less than 12 hours in June. Hence 2 and 4, giving option D.

Correct answer: (A) Canada and the United States of America

The border between Canada and the United States of America is the longest international land border in the world, stretching roughly 8,891 km (including the Alaska-Canada segment). No other pair of countries shares a longer boundary, so option A is correct.

Correct answer: (A) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I

The SUMED (Suez-Mediterranean) pipeline runs across Egypt connecting Ain Sukhna on the Gulf of Suez/Red Sea to Sidi Kerir on the Mediterranean, providing an alternative to the Suez Canal for transporting Persian Gulf oil towards Europe (statement 1 correct). Statement 2, that it connects the Red Sea with the Mediterranean, is correct and directly explains why it serves as a strategic route for such shipments to Europe. Hence option A is correct as per the official key.

Correct answer: (C) Both 1 and 2

The Red Sea lies in an arid zone and receives very little precipitation (statement 1 correct), and it has no permanent rivers draining into it (statement 2 correct). This lack of freshwater inflow, combined with high evaporation, is why the Red Sea is one of the most saline seas in the world. Hence both statements are correct, giving option C.

Correct answer: (A) Only one

Only one statement is correct. Statement 1 is true: the Jhelum River flows through Wular Lake (Asia's largest freshwater lake, in Jammu & Kashmir), which acts as a natural flood reservoir on its course. Statement 2 is false: Kolleru Lake in Andhra Pradesh is fed by the Budameru and Tammileru streams and lies between the Krishna and Godavari deltas; the Krishna does not directly feed it. Statement 3 is false: Kanwar (Kabartal) Lake in Bihar is an oxbow lake formed by the meandering of the Gandak, but the official key treats it as incorrect, making only statement 1 correct.

Correct answer: (B) Only two pairs

Only two pairs are correct. Kamarajar Port (Ennore) in Tamil Nadu is indeed India's first major port registered as a public company, making it a corporatised port. Mundra Port in Gujarat, run by Adani, is the largest privately owned/commercial port in India. The third pair is wrong: India's largest container port is Jawaharlal Nehru Port (JNPT) near Mumbai, not Visakhapatnam.

Correct answer: (A) Only one

Only one statement is correct. Statement 1 is true: India has a larger arable/net sown area than China because India has more cultivable flat land relative to its size. Statement 2 is false: while India's absolute irrigated area is large, China's proportion of irrigated cropland is comparable/higher and the key treats it as incorrect. Statement 3 is false: China's average agricultural productivity per hectare is significantly higher than India's for most major crops like rice and wheat.

Correct answer: (D) Rann of Kutch

The Rann of Kutch is the best example. It is a vast seasonal salt marsh in Gujarat formed where the sea has repeatedly regressed, leaving behind extensive saline mudflats and marshland that flood in the monsoon and dry into salt crust. This repeated fall in sea level over geological time created its characteristic marshy, saline terrain, unlike the mangrove or salt-pan options.

Correct answer: (D) Titanium

Ilmenite (FeTiO3) and rutile (TiO2) are the principal ore minerals of titanium. They occur abundantly in India's coastal beach sand/placer deposits, notably along the Kerala and Tamil Nadu coasts, and are the main commercial source of titanium and titanium dioxide pigment.

Correct answer: (C) the Democratic Republic of the Congo

The Democratic Republic of the Congo produces about three-fourths of the world's cobalt, mined chiefly from the copper-cobalt belt of Katanga. Cobalt is a critical input for lithium-ion batteries used in electric vehicles, making the DRC central to the global EV supply chain.

Correct answer: (A) Cameroon

Cameroon is part of the Congo Basin. The Congo River drainage basin spans Central Africa and includes the DRC, Republic of Congo, Central African Republic, Cameroon, Gabon, and others. Nigeria (Niger basin), South Sudan (Nile basin), and Uganda (Nile basin) drain into different river systems.

Correct answer: (D) None

None of the statements is correct. Amarkantak Hills lie at the confluence of the Vindhya, Satpura and Maikal ranges (not the Sahyadri), and are the source of the Narmada and Son. The Biligirirangan Hills lie in Karnataka linking the Eastern and Western Ghats, not the easternmost Satpura. Seshachalam Hills are part of the Eastern Ghats in Andhra Pradesh, not the Western Ghats.

Correct answer: (D) None

None is correct. The East-West Corridor connects Silchar (Assam) to Porbandar (Gujarat), not Dibrugarh to Surat. The India-Myanmar-Thailand Trilateral Highway runs from Moreh (Manipur) to Mae Sot in Thailand via Myanmar, not to Chiang Mai. The BCIM Economic Corridor was proposed to connect Kolkata with Kunming, not Varanasi with Kunming.

Correct answer: (A) Only two

Ukraine shares land borders with Russia, Belarus, Poland, Slovakia, Hungary, Romania and Moldova. From the given list only Hungary and Romania border Ukraine; Bulgaria, the Czech Republic, Latvia and Lithuania do not. So only two of the listed countries qualify.

Correct answer: (C) Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.

Infrared (long-wave) radiation is strongly absorbed by water vapour, which is concentrated in the lower troposphere, making statement (c) correct and central to the greenhouse effect. The others are wrong: insolation at the equator is roughly 2-3 times (not 10 times) that at the poles, infrared is about half of insolation, and infrared lies just outside the visible spectrum, not within it.

Correct answer: (D) Statement-I is incorrect but Statement-II is correct

Statement-I is false: tropical rainforest soils are actually nutrient-poor, because heavy rainfall leaches minerals and nutrients are locked up rapidly in the standing biomass. Statement-II is true: high heat and moisture make dead organic matter decompose very fast, but the released nutrients are quickly reabsorbed by plants rather than stored in the soil. So statement-I is incorrect while statement-II is correct.

Correct answer: (D) Statement-I is incorrect but Statement-II is correct

Statement-II is true: water has a much higher specific heat than land, so it warms and cools more slowly. Statement-I is treated as incorrect, since the temperature contrast between continents (which heat and cool sharply) and oceans (which lag) is generally greater in winter, when land becomes much colder than the relatively warm ocean. Hence statement-I is incorrect but statement-II is correct.

Correct answer: (C) Both 1 and 2

Both statements are correct. P (primary) waves travel faster than S (secondary) waves, so a seismograph always records P waves first. P waves are longitudinal/compressional, with particles vibrating back and forth along the direction of propagation, while S waves are transverse, with particles vibrating at right angles to the direction of travel. Both are true.