In which of the following states is there hardly any differences in day and night temperatures?

The correct answer is D, Tundra Forest. Mosses and lichens are the typical plants of the tundra, the cold treeless belt that lies beyond the coniferous forests of the far north. The growing season there lasts only a few weeks, the subsoil stays frozen as permafrost and the soil layer is thin, so tall plants with deep roots cannot survive, while low cushions of moss and lichen along with sedges and dwarf shrubs can. Reindeer and caribou feed on lichen, which is why one kind is called reindeer moss. A is wrong because tropical rain forests are hot and wet and carry tall evergreen trees in several layers. B is wrong because temperate forests are made of broad-leaved deciduous trees such as oak, elm and maple. C is wrong because coniferous or taiga forests carry pine, fir and spruce, the softwood belt lying just south of the tundra. Exam tip: moving from the pole towards the equator the order is tundra, taiga or coniferous, temperate and then tropical.

The correct answer is A, Endogenic Forces. Mountains are built by endogenic forces, the forces that act from inside the earth and raise, bend or break the crust. They draw their energy from the earth’s internal heat and from the movement of the plates. Slow or diastrophic movements fold and lift rock over millions of years and give rise to fold mountains such as the Himalayas, the Alps and the Andes, while sudden movements appear as earthquakes and volcanic eruptions, which build volcanic mountains. Endogenic forces are therefore called constructive, because they create relief on the surface. B is wrong because exogenic forces such as running water, wind, waves and glaciers act on the surface and wear mountains down instead of raising them. C is wrong because gravity only helps loose material move downhill, as in landslides. D is wrong because the earth’s magnetic field records plate movement but does not lift land. Exam tip: endogenic forces build through diastrophism and volcanism, exogenic forces destroy through weathering and erosion.

The correct answer is A, France. France has twelve time zones, more than any other country, because its overseas departments and territories are scattered across the Pacific, the Indian Ocean, the Atlantic and the Caribbean. Mainland France keeps one zone, and places such as French Polynesia, New Caledonia, Reunion, Guadeloupe and French Guiana add the rest, so a single country spans almost the whole clock. Russia comes second with eleven zones, and these lie in one continuous landmass from Kaliningrad in the west to Kamchatka in the east. B is wrong because the United States has nine standard zones at home and eleven in all when its territories are counted, still short of France. C is wrong because Russia has eleven zones, one less than France. D is wrong because the United Kingdom keeps a single zone at home and does not reach France even with its overseas territories. Exam tip: France 12 zones, Russia 11, the United States 11 with territories, while India keeps one zone based on 82 degrees 30 minutes East.

The correct answer is D, Kanwar Sain. The engineer Kanwar Sain conceived the plan in 1948 of carrying the surplus water of the Sutlej and the Beas into the Thar desert, and the canal was taken up on his design. Work began on 31 March 1958 on what was then called the Rajasthan Canal, which draws water from the Harike barrage below the meeting of the Sutlej and the Beas in Punjab. It was renamed the Indira Gandhi Canal in 1984 and, with its branches, is the longest irrigation canal in India, turning parts of Sriganganagar, Hanumangarh, Bikaner and Jaisalmer into cropland. A is wrong because Mohanlal Sukhadia was a Chief Minister of Rajasthan in whose years the work went ahead. B is wrong because Jawaharlal Nehru was the Prime Minister of the day, not the author of the plan. C is wrong because Jainarayan Vyas was also a Chief Minister. Exam tip: conceived by Kanwar Sain in 1948, work started 1958, renamed 1984.

The correct answer is A, Tube well. Tube wells irrigate the largest share of the net irrigated area of Rajasthan, and groundwater drawn through tube wells and wells together waters the greater part of the state's fields. The reason is the climate: rainfall is low and uncertain over most of the state and perennial rivers are few, so a farmer who wants a second crop has to pump water. This heavy drawing of groundwater has pushed many blocks of Rajasthan into the over-exploited category, which is why drip and sprinkler irrigation are pressed in the state. B is wrong because ponds and tanks serve only small pockets, mostly in the south and south-east. C is wrong because open wells, once the mainstay, now water a much smaller area than tube wells. D is wrong because canals, led by the Indira Gandhi Canal, come second and are limited to the north-west and the Chambal command. Exam tip: in Rajasthan groundwater leads, tube wells first and canals second.