Geography Mixed Quiz: Set 58

The correct answer is A, Earth. Among the four rocky inner planets, Earth is the largest, with a diameter of about 12,742 km.

The inner or terrestrial planets are Mercury, Venus, Earth and Mars, all made of rock and metal. Earth is the biggest and also the densest planet in the solar system. Venus comes a close second at about 12,104 km and is often called Earth's twin for its similar size. Mars is roughly half Earth's width and Mercury is the smallest planet of all. The giant outer planets, led by Jupiter, are far larger, but none of them is in the options.

B is wrong: Venus, at about 12,104 km across, is slightly smaller than Earth.

C is wrong: Mars measures about 6,779 km, roughly half of Earth's diameter.

D is wrong: Mercury, about 4,880 km across, is the smallest planet in the solar system.

Exam tip: inner planets by size: Earth > Venus > Mars > Mercury; overall largest is Jupiter.

The correct answer is A, 1 only. In January the northern oceans are warmer than the frozen continents, so isotherms bend north over the sea and south over the land; the Gulf Stream and North Atlantic Drift are warm currents, not cold ones.

Isotherms are lines joining places of equal temperature. In the northern hemisphere winter, land loses heat quickly and becomes very cold, while the ocean keeps its warmth. A given temperature is therefore found further north over the ocean and further south over the continents such as Siberia, which makes the lines bend. Statement 2 is wrong: the Gulf Stream and the North Atlantic Drift carry warm tropical water into the North Atlantic, making it warmer, and that warmth is why the isotherms bend sharply north there, keeping ports of north-west Europe ice-free.

B is wrong because statement 2 calls warm currents cold.

C is wrong because statement 2 is false.

D is wrong because statement 1 is a correct inference.

Exam tip: January isotherms bend poleward over oceans and equatorward over land; Gulf Stream and North Atlantic Drift are warm currents.

The correct answer is D, Olivine. Olivine is a silicate of magnesium and iron that forms greenish crystals and is common in basalt.

Olivine takes its name from its olive-green colour. It crystallises early from hot magma that is low in silica, which is why it turns up in basalt, gabbro and peridotite and makes up much of the Earth's upper mantle. Its main elements are magnesium, iron and silica. A clear, gem-quality olivine is sold as the jewel peridot. Feldspar and quartz, by contrast, are the commonest minerals of the crust and are richer in silica.

A is wrong: amphibolite is a metamorphic rock made mostly of amphibole minerals, not a single mineral.

B is wrong: feldspar is made of silicon and oxygen with sodium, potassium, calcium and aluminium, and is light cream to salmon pink.

C is wrong: pyroxene contains calcium and aluminium along with magnesium, iron and silica, and is usually green or black.

Exam tip: olivine = green, Mg-Fe silicate, basalt, gem peridot; feldspar = half of the crust.

The correct answer is C, Statement I is true but Statement II is false. Plantations do lie mostly in the humid tropics, but the soils there are generally poor, not highly fertile.

Plantation farming grows a single cash crop such as tea, coffee, rubber, sugarcane, cocoa, banana or oil palm on large estates with heavy capital and hired labour. It spread in the humid tropics of Asia, Africa and Latin America, largely under colonial rule, because these crops need high temperatures and heavy rain throughout the year. The same heavy rain leaches nutrients out of the soil, leaving laterite and other weathered red soils that are low in humus and plant food; the lush forest survives by quickly recycling nutrients from fallen leaves.

A is wrong: Statement II is false, so it cannot explain Statement I.

B is wrong: it treats the false Statement II as true.

D is wrong: Statement I is true and Statement II is false, the reverse of this option.

Exam tip: humid tropics have lush forest but leached, infertile laterite soil; plantations need the climate, not rich soil.

The correct answer is C, Both 1 and 2. S-waves are transverse waves: they shake the ground at right angles to their direction of travel, and that sideways motion forms crests and troughs.

An earthquake sends out two kinds of body waves. P-waves (primary) are the fastest and work like sound waves, pushing and pulling the material in the same direction as the wave moves; they pass through solids, liquids and gases. S-waves (secondary) arrive later and vibrate the material perpendicular to the wave direction in the vertical plane, which is why they create troughs and crests. S-waves travel only through solids, and their absence beyond the shadow zone told scientists that the outer core is liquid.

A is wrong: statement 2 is also correct, since the perpendicular vibration is what defines an S-wave.

B is wrong: statement 1 is correct too, as the crests and troughs follow from that vibration.

D is wrong: both statements describe S-waves accurately.

Exam tip: P-waves are longitudinal and go through all states of matter; S-waves are transverse and go through solids only.

The correct answer is D, Polar type. Koeppen grouped climates by temperature and rainfall and gave each group a capital letter, and E stands for the polar group, where the mean temperature of the warmest month stays below 10 degrees Celsius. In India this type is met only in the high Himalaya, in Ladakh and the upper reaches of Jammu and Kashmir, where snow lies for much of the year and the vegetation is tundra-like. Option A is wrong because tropical savannah is Aw in the scheme and covers most of the peninsular interior. Option B is wrong because the hot desert of western Rajasthan is marked BWhw. Option C is wrong because monsoon with a dry summer is As, the climate of the Coromandel coast of Tamil Nadu, which gets most of its rain from the retreating monsoon. Exam tip: Koeppen's first letters are A tropical, B dry, C warm temperate, D cold snow forest and E polar.

The correct answer is A, 1 only. Water vapour thins out quickly with height, but it is most plentiful in the warm tropics, not at the poles.

Water vapour is a variable gas of the atmosphere, making up anything from almost nil to about 4% of the air by volume. It enters the air by evaporation and transpiration, and warm air can hold far more of it than cold air. That is why about 90% of it stays in the lowest few kilometres of the troposphere and its share falls steadily with altitude. For the same reason it is highest in warm, humid equatorial regions, where it can reach 4%, and lowest over the cold poles and dry deserts, where it may be below 1%. It absorbs heat from the Earth and so helps keep the planet warm.

B is wrong: the poles are cold and hold the least water vapour.

C is wrong: it includes the false statement 2.

D is wrong: statement 1 is correct.

Exam tip: water vapour is up to 4% in warm, wet tropics and under 1% in cold or dry areas; it decreases with altitude.

The correct answer is B, only statement B is true. Statement B is sound: for the poor and for people of the lower castes, the new jobs in colonial cities were a way out of the control of upper-caste landowners in the village and of the daily humiliation they suffered there, and this pull is part of every account of colonial urbanisation. The first statement is false because of the word only: it was not only the rich who left the villages for work in the growing cities, and in fact the poor and the landless formed the bulk of the migration to mills, docks, railways and construction sites. So option A, which calls the first statement true, is wrong, and option C, which calls both false, is wrong because the second statement is true. Option D, which calls both true, is wrong for the same reason as A.

The correct answer is D, Rann of Kutch. The Rann was once a shallow arm of the Arabian Sea, and as the sea withdrew from it, aided by the uplift of the land, it was left as the vast salt marsh seen today.

The Great and Little Rann of Kutch in Gujarat cover tens of thousands of square kilometres of flat, salty mudflats that are flooded during the monsoon and turn into a white salt desert in the dry season. Geologists explain the landscape by repeated changes in sea level together with tectonic uplift: the former gulf became cut off from the sea and was filled by sediments brought by rivers such as the Luni. Its size and origin make it the classic Indian example of a marsh left behind by a retreating sea.

A is wrong: Bhitarkanika in Odisha is a mangrove forest in the delta of the Brahmani and Baitarani rivers, formed by river and tidal action.

B is wrong: Marakkanam in Tamil Nadu is a coastal salt-making area, not an extensive marshland.

C is wrong: Naupada in Andhra Pradesh is a small coastal swamp and salt-pan area.

Exam tip: Rann of Kutch = former arm of the Arabian Sea, now a seasonal salt marsh; home of the Indian wild ass in the Little Rann.

The correct answer is C, seafloor spreading. New oceanic crust is made at mid-ocean ridges, where magma rises, cools and is pushed outwards on both sides, and that process is called seafloor spreading.

Harry Hess set out the idea in the 1960s. Along a ridge such as the Mid-Atlantic Ridge two plates move apart, basaltic lava fills the gap and hardens into fresh crust, so the rock grows older as you move away from the ridge on either side. The matching magnetic stripes on the two sides of a ridge are the proof of this. The crust destroyed in subduction zones balances the crust created here, which is why the earth does not grow larger.

A is wrong: subduction destroys crust by pushing one plate under another. B is wrong: an earthquake only releases strain that has built up. D is wrong: convection in the mantle drives plate movement but does not itself make crust.

Exam tip: ridges build crust and trenches consume it, so spreading and subduction keep the earth's surface area constant.

The correct answer is B, Gomati - Ghaghara - Gandak - Kosi. Below Prayagraj the Ganga receives the Gomati first, then the Ghaghara, then the Gandak and finally the Kosi as it flows east.

The Gomati, which rises near Pilibhit and flows past Lucknow and Jaunpur, joins the Ganga near Kaithi in Ghazipur district of Uttar Pradesh. The Ghaghara, coming down from Nepal as the Karnali, meets the Ganga near Chhapra in Bihar. The Gandak, known as the Narayani in Nepal, joins at Sonpur opposite Patna. The Kosi, the "Sorrow of Bihar" famous for shifting its course, joins near Kursela in Katihar district, close to the border with Jharkhand and West Bengal.

A is wrong: it puts the Ghaghara before the Gomati, but the Gomati joins further west.

C is wrong: it puts the Ghaghara first and the Kosi before the Gandak.

D is wrong: the Gandak joins near Patna, well west of the Kosi confluence at Kursela.

Exam tip: left-bank order below Prayagraj = Gomati (Ghazipur), Ghaghara (Chhapra), Gandak (Sonpur-Patna), Kosi (Kursela).

The correct answer is D, 2.4%. India covers about 32.87 lakh square kilometres, which is roughly 2.4 per cent of the world's total land area.

That small share supports about 17 to 18 per cent of the world's people, and this gap between land and population is what the question is really testing. By area India is the seventh largest country in the world, after Russia, Canada, the United States, China, Brazil and Australia. Its mainland runs from about 8 degrees 4 minutes North to 37 degrees 6 minutes North, and from 68 degrees 7 minutes East to 97 degrees 25 minutes East, giving a north to south length of about 3,214 km and an east to west width of about 2,933 km.

A is wrong: 2.8 per cent is higher than India's actual share. B is wrong: 3.9 per cent overstates that share by more than half. C is wrong: 4.2 per cent is nearly double the correct figure.

Exam tip: India has 2.4 per cent of the world's land area and about 17 per cent of its population, and is the seventh largest country.

The correct answer is A, Lonar Lake. Lonar Lake in Buldhana district of Maharashtra fills a crater made by a meteorite impact.

The Lonar crater was formed in prehistoric times when a meteorite struck the basalt rock of the Deccan Plateau. It is about 1.8 km across, and the lake inside it is both saline and alkaline. It is one of the very few known hypervelocity impact craters in basaltic rock anywhere on Earth, which makes it important to geologists. It has been declared a Ramsar site and is a geo-heritage site.

B is wrong: Sambhar in Rajasthan is India's largest inland salt lake, formed in a shallow basin, not a crater.

C is wrong: Chilika in Odisha is a brackish-water lagoon on the east coast, Asia's largest.

D is wrong: Vembanad in Kerala is a long backwater lagoon fed by several rivers.

Exam tip: Lonar = meteorite crater lake (Maharashtra); Sambhar = salt lake; Chilika = lagoon; Wular = largest freshwater lake.

The correct answer is C, National Waterway 16. The Barak between Lakhipur and Bhanga, about 121 km, serves the Barak valley of southern Assam, and through Karimganj it joins the protocol route across Bangladesh, which makes it the lifeline of a region cut off from the rest of Assam by hills. Option A is wrong because National Waterway 2 is the Brahmaputra from Dhubri to Sadiya, in the other valley of the same state. Option B is wrong because the Barak stretch had earlier been declared as National Waterway 6 under a separate law, but after the 2016 Act the Barak waterway is listed as NW-16, which is the number asked for today. Option D is wrong because National Waterway 110 is the Yamuna from Delhi to Prayagraj.

The correct answer is B, Desert, Tropical thorny, Moist deciduous, Mangrove. The route runs from the dry west to the wet east coast, so the vegetation changes as rainfall rises.

Bikaner lies in the Thar Desert of western Rajasthan, where rainfall is below about 25 cm and only desert plants such as khejri and cactus grow. Moving east through eastern Rajasthan and the drier parts of central India, rainfall of roughly 25 to 70 cm supports tropical thorn forests of acacia, babool and ber. Further east, in Chhattisgarh, Jharkhand and Odisha, rainfall of about 100 to 200 cm supports moist deciduous forests of sal and teak. Konark is on the Odisha coast near the Mahanadi delta, where tidal creeks support mangroves.

A is wrong: it puts thorny vegetation before the desert, but Bikaner itself is in the desert.

C is wrong: it starts with moist deciduous forest and ends with desert, the reverse of the journey.

D is wrong: mangroves grow only at the coast, so they must come last, after the inland deciduous forests.

Exam tip: more rain, richer forest: desert < thorn < dry deciduous < moist deciduous < evergreen; mangroves on tidal coasts.

The correct answer is A, Fold Mountain. The Himalayas are young fold mountains, formed when the sediments of the Tethys Sea were squeezed and folded as the Indian plate collided with the Eurasian plate.

Because that collision still continues, the range is rising even now and the whole belt stays earthquake prone. The Alps, the Rockies and the Andes belong to the same class, and like them the Himalayas run in parallel ranges — the Himadri, the Himachal and the Shiwaliks.

Option B, plateau mountain, is not a standard category; plateaus such as the Deccan are flat uplands, not folded ranges. Option C, fault-block mountain, forms when land between two faults is lifted or its sides sink, as in the Satpura and Vindhya blocks. Option D, dome mountain, forms when magma pushes the rock above it upward without erupting.

Exam tip: Himalayas, Alps, Andes and Rockies are young fold mountains; Satpura is a block mountain.

The correct answer is C, New Guinea. With an area of about 7.86 lakh sq km, New Guinea is the world's second-largest island, after Greenland.

New Guinea lies just north of Australia and is shared by two countries: its western half belongs to Indonesia and its eastern half is the mainland of Papua New Guinea. It is mountainous and covered with dense rainforest. Australia is not counted here because it is treated as a continent. After Greenland and New Guinea, the next largest islands are Borneo, Madagascar, Baffin Island and Sumatra, in that order.

A is wrong: Borneo, shared by Indonesia, Malaysia and Brunei, is the third largest, at about 7.43 lakh sq km.

B is wrong: Madagascar, off the south-east coast of Africa, is fourth, at about 5.87 lakh sq km.

D is wrong: Sumatra, in Indonesia, is sixth, at about 4.73 lakh sq km.

Exam tip: largest islands in order: Greenland, New Guinea, Borneo, Madagascar, Baffin, Sumatra.

The correct answer is A, Playa. A playa is the flat, fine-grained floor of a shallow desert basin that holds water only for a short time after rain.

In deserts, streams from the surrounding uplands carry silt and clay into closed basins called bolsons. After a storm a temporary lake forms; the water soon evaporates and leaves a level bed of fine sediment, often crusted with salt. Such a salt-covered playa is called an alkali flat or salina. The Rann of Kachchh and the salt lakes of Rajasthan show similar features.

B is wrong: an oasis is a fertile spot in a desert where groundwater reaches the surface; it is not a dry lake bed.

C is wrong: a drumlin is an oval hill of glacial till shaped by moving ice, a glacial and not a desert landform.

D is wrong: a natural levee is a raised bank of sediment built along a river by repeated flooding.

Exam tip: desert depositional landforms: playa, bajada and alluvial fan; desert erosional landforms: mushroom rock, inselberg and yardang.

The correct answer is D, Marine West coast climate. Mild temperatures with small ranges, rain in every month and a total of about 50 to 250 cm describe the west coast marine (Cfb) type.

This climate is found on the western margins of continents in the middle latitudes, roughly 40 to 60 degrees, as in north-western Europe, British Columbia, southern Chile, Tasmania and New Zealand. Prevailing westerlies blow in from the ocean all year, bringing frequent cyclonic rain and keeping summers cool and winters mild, so both the annual and daily ranges stay small. Warm ocean currents such as the North Atlantic Drift add to the mildness.

A is wrong: the equatorial climate has heavy rain, usually above 200 cm, and its daily range is greater than its small annual range.

B is wrong: the China type has hot summers and cool winters, so its annual range is large, with rain peaking in summer.

C is wrong: humid subtropical is another name for the China type, with the same large summer-winter contrast.

Exam tip: marine west coast = British type, Cfb, westerlies, rain all year, mild winters and cool summers.

The correct answer is C, five. The states along the Bangladesh frontier are West Bengal, Assam, Meghalaya, Tripura and Mizoram, with West Bengal carrying the longest stretch. Option A and option B are the figures reached by leaving out Mizoram, whose border with Bangladesh is short, or Assam, whose frontier lies in the south-west of the state. Option D, six, is what students mark when they wrongly add Manipur or Nagaland, both of which face Myanmar and not Bangladesh. The pattern is worth learning as a set of counts: five states for Bangladesh, five for Nepal, four for Myanmar, four for Bhutan, and for China five units counting Ladakh, Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh. It is also worth remembering that Tripura is almost surrounded by Bangladesh on three sides, which is why its border is long in proportion to the size of the state.