World Geography Questions and Answers

Answer: B

Correct answer: A rapid mass movement of snow and ice down a slope

An avalanche is the rapid downslope movement of a mass of snow, often carrying ice, rock and debris with it. It is a form of mass wasting, driven by gravity once the strength holding the snowpack in place is exceeded. The commonest and most dangerous type is the slab avalanche, in which a cohesive layer of snow releases across a weak layer beneath it - typically buried surface hoar or faceted crystals formed during a cold clear spell. Slopes between about 30 and 45 degrees are the most prone: gentler ones do not release, steeper ones shed snow continuously. Triggers include fresh heavy snowfall, rapid warming, rain on snow, and the weight of a person crossing the slope, which accounts for most fatal avalanches. They are a serious hazard in the Himalaya, particularly for troops posted at high altitude and along routes such as the road to Siachen, and in Himachal Pradesh, Uttarakhand and Jammu and Kashmir.

Answer: A

The initial phase of a magnetic storm is preceded by a storm sudden commencement - the abrupt jump in the horizontal field, lasting a few minutes, as the shock front of a solar wind gust compresses the magnetosphere.

The field then stays slightly elevated through the initial phase, before the main phase drives it sharply downward.

Answer: D

Correct answer: Frost shattering of rock

Frost shattering is physical, or mechanical, weathering: rock is broken into smaller pieces with no change in its chemical composition. Water seeps into a crack, freezes, and expands by about nine per cent, prising the crack wider; repeated cycles split the rock apart. It is most effective where temperatures cross freezing point frequently, as on high mountains, and produces the scree slopes below cliffs. The other three are chemical processes, which alter the minerals themselves. Carbonation dissolves limestone in weakly acidic rainwater, creating caves and karst; oxidation rusts iron-bearing minerals and gives lateritic soils their red colour; and hydrolysis converts feldspar into clay, which is the commonest chemical reaction in the crust. The two reinforce each other: physical weathering breaks rock into fragments and so multiplies the surface area available for chemical attack. Physical weathering dominates in cold and arid climates, chemical in hot and humid ones.

Answer: A

Correct answer: Mandarin Chinese

Mandarin Chinese has the most native speakers of any language, around 940 million, chiefly because of the population of China. Spanish is second by that measure, then English and Hindi, though the order varies with how dialects and closely related varieties are counted. The picture changes completely if total speakers are counted rather than native ones. English then leads by a wide margin, with well over a billion speakers, because it is so widely learnt as a second language and functions as the working language of international business, science and aviation. The distinction between first-language and total speakers is exactly what such questions turn on, so it is worth reading which is meant. India’s own position is unusual: it has no single national language, but Hindi and English serve as the official languages of the union, alongside 22 scheduled languages.

Answer: A

The soils of the south-eastern United States are Ultisols - deeply weathered, acid, reddish soils that have lost most of their bases through long leaching under a warm, humid climate.

Alfisols are younger and richer in bases, Aridisols are desert soils, and Mollisols are the dark, fertile grassland soils of the prairies.

Answer: C

The Seychelles is an archipelago of about 115 islands in the Indian Ocean, roughly 1,500 km east of mainland Africa.

Answer: D

Dalmianagar in the Rohtas district of Bihar is known for its cement works, established in the 1930s by the Dalmia group, after whom the town is named.

Limestone from the neighbouring Kaimur hills and coal from the Jharia field supplied the plant, which also made paper and sugar.

Answer: A

Where the zone of maximum stream velocity swings down towards the bed, the extra energy scours the channel and excavates a deep scoured pool.

Between the pools the velocity core lies higher in the flow, so material is deposited instead, building the shallow gravel bars called riffles. Pools and riffles therefore alternate along a channel.

Answer: C

Correct answer: Solar power

Solar power is renewable: the resource is replenished continuously on any human timescale, and using it does not diminish what is available tomorrow. Wind, hydro, tidal, geothermal and biomass belong to the same class. Coal and natural gas are fossil fuels, formed over hundreds of millions of years from buried organic matter, so the stock is fixed and burning it releases carbon dioxide that had been locked away. Uranium is the interesting case. Nuclear fission emits almost no carbon dioxide in operation, which makes it a low-carbon source, but the uranium ore itself is a finite mineral deposit, so it is not renewable. Low-carbon and renewable are two different tests, and nuclear passes one and fails the other. India’s renewable capacity has grown rapidly, with solar the fastest-expanding component, and a large share of it in Rajasthan, Gujarat and Karnataka.

Answer: D

All three statements are part of plate tectonic theory: new oceanic crust is created at mid-ocean ridges and the continents drift as the plates move; convection currents in the mantle drive that motion; and the oceanic crust is destroyed at subduction zones where one plate descends beneath another.

Creation, driving mechanism and destruction together make one coherent theory, so the combined choice is correct.