In which of the following Himalayan ranges is the Banihal Pass situated?

The correct answer is A, 40 to 70 degrees. The cold snow-forest climate, group D in Koeppen's scheme, lies in the continental interiors of the northern hemisphere between about 40 and 70 degrees north, across northern Europe, Siberia, Canada and Alaska. It has no counterpart in the southern hemisphere, because there is no large landmass in those latitudes there. Winters are long and severe with the coldest month below minus 3 degrees Celsius, summers are short and mild, and the natural cover is the coniferous taiga of pine, fir and spruce. Its two divisions are Df, moist through the year, and Dw, with a dry winter. B is wrong because 30 to 50 degrees is the warm temperate C belt of Mediterranean and China type climates. C is wrong because latitude cannot exceed 90 degrees. D is wrong because 15 to 20 degrees lies in the tropics. Exam tip: group D cannot occur in the southern hemisphere.

The correct answer is A, Interiors of India. The interior of the country has the sharpest difference between summer and winter because it lies far from the sea, and this effect is called continentality. Land heats and cools faster than water, so places such as Churu, Jaisalmer and Nagpur can cross 48 degrees Celsius in May and fall close to freezing in January, giving a yearly range of over 20 degrees. B is wrong because the sea breeze keeps coastal cities such as Mumbai and Chennai even through the year, with a range of only a few degrees. C is wrong because hill stations are cool in all seasons, since height, not distance from the sea, decides their temperature. D is wrong because the Andaman and Lakshadweep islands are surrounded by water and have an almost equable maritime climate. Exam tip: continentality raises the annual range of temperature, while the sea reduces it, so Mumbai and Nagpur lie on the same latitude but feel very different.

The correct answer is D, Dw. In Koeppen's scheme the capital letter gives the broad climatic group and the small letters add the rainfall and temperature detail. D stands for cold snow-forest climate, and the small letter w stands for a dry winter, so Dw is cold climate with dry winters, the climate of north-east Asia around Manchuria and Siberia. Koeppen used five main groups: A tropical, B dry, C warm temperate, D cold snow-forest and E polar. A is wrong because EF is the ice-cap climate of Antarctica and Greenland, where no month averages above freezing. B is wrong because Df is a cold climate with no dry season, rain and snow through the year. C is wrong because ET is the tundra climate, where the warmest month stays between 0 and 10 degrees Celsius. Exam tip: f means wet all year, w a dry winter and s a dry summer.

The correct answer is B, 5. The standard school classification divides India's natural vegetation into five groups: tropical evergreen rainforests, tropical deciduous or monsoon forests, tropical thorn forests and scrubs, montane forests, and mangrove or tidal forests. The deciding factor is rainfall, with temperature and altitude next. Evergreen forests need over 200 cm of rain and are found in the Western Ghats, the north-east and the Andamans; deciduous forests, the most widespread type, grow between 70 and 200 cm; thorn forests take over below 70 cm in Rajasthan and the dry Deccan; montane forests change with height in the Himalayas; and mangroves line the deltas of the Ganga, Mahanadi, Godavari and Krishna. A, C and D are wrong because they do not match this five-fold grouping. Exam tip: remember the order evergreen, deciduous, thorn, montane, mangrove, arranged from wettest to driest and then by height.

The correct answer is D, Underground water. A stalagmite is built up on the floor of a limestone cave by water that seeps in from above, so the agent at work is underground water. Rainwater charged with carbon dioxide dissolves limestone as it percolates through joints; when a drop reaches the cave and gives up its carbon dioxide, a little calcium carbonate is left behind. Over thousands of years these deposits grow downward from the roof as stalactites and upward from the floor as stalagmites, and where the two meet they join into a pillar. Such caves and sink holes make up karst topography, named after the Karst region of Europe. A is wrong because glaciers leave moraines, drumlins and eskers. B is wrong because wind builds sand dunes and loess plains. C is wrong because surface water builds deltas, flood plains and alluvial fans. Exam tip: a stalactite hangs from the ceiling and a stalagmite grows from the ground.