Ans: B 

Exp:

The Central Asian Steppe are the temperate grasslands of the World. A steppe is a dry, grassy plain. Steppes occur in temperate climates, which lie between the tropics and Polar Regions. Steppes are located in the heart of the continents, meant they have little maritime influence. Their climate is thus continental with extremes of temperature. Summers are warm and winters are very cold. Steppes are semi-arid, meaning they receive 25 to 50 centimeters (10-20 inches) of rain each year. Temperate regions have distinct seasonal temperature changes, with cold winters and warm summers. There is enough rain to support short grasses, but not enough for tall grasses or trees to grow. Many kinds of grasses grow on steppes, but few grow taller than half a meter (20 inches). Short grasses that grow naturally on steppes provide grazing for cattle, goats, horses, camels, and sheep. These grasslands were dominated by nomadic and semi-nomadic peoples like the kirghiz. The region was sparsely populated.Many of the world’s steppes have been converted to cropland and pasture. Sometimes steppes are overgrazed, which occurs when there are more animals than the land can support.

Ans: B

Exp:

Option a is incorrect: Laurentian Type climate is characterized by cold, dry winters and warm, wet summers. 

Option b is correct: Warm Temperate western margin climate, aka Mediterranean type climate is found in few areas of the world. It is entirely confined to the western portion of continental masses, between 30o – 45o north and south of equator. The basic cause of this type of climate is shifting of wind belts. The Mediterranean type climate is characterised by very distinctive climatic features – A dry, warm summer with off-shore trades and a concentration of rainfall in winter with on-shore westerlies. The best-developed form of this climatic type is found in central Chile. Other Mediterranean regions include: California (around San Francisco), South-western tip of Africa (around Cape Town), Southern Australia and south-west Australia (Swanland).

Option c is incorrect: Savannah Type climate has onshore winds in summer and off-shore in winter. That is wet summers and dry winters. 

Option d is incorrect: China Type climate is found in the east coast in both the hemispheres and the region has fairly uniform distribution of rainfall throughout the year Knowledge Base: This climatic region is famous for orchard farming. A wide range of citrus fruits such as oranges, lemons, limes, citrons and grapefruits are grown.

Ans: B

Exp:

The term “buran” in the Siberian type climate refers to northerly polar winds of Eurasia that cause violent blizzards with temperatures plummeting below freezing point. These winds, similar to the blizzards of Canada, blow at speeds of 50 mph or more and at a temperature of 50°F below freezing-point, creating challenging conditions with visibility greatly reduced. With extreme temperatures, such as those recorded in Verkhoyansk, where -90°F was once recorded, Siberia is often referred to as the ‘cold pole of the earth.’ These harsh conditions contribute to the sparse population of the region, although it is gradually being developed.

Ans: C

Exp:

Statement 1 is incorrect: Thermosphere lies above the mesosphere and extends up to 350 km above the ground. In this region the temperature has a positive gradient with temperatures reaching values in excess of 1100°C at heights above 120 in. The absorption of solar extreme UV radiation and X-rays by oxygen and nitrogen at these heights causes the temperature to increase.

Statement 2 is correct: Spectacular lights and colours called the Aurora can be seen primarily in thermosphere part of the atmosphere, particularly in the Polar Regions(in the northern hemisphere the Aurora borealis and in the southern hemisphere the Aurora australis). These are created when charged particles from the Sun collide with the molecules of air in the upper atmosphere and deflected towards the poles. The charged particles change their charge due to the collisions and glow.

Statement 3 is incorrect: Meteors burn up in the Mesosphere because, in the Mesosphere, there are enough gases to cause friction and create heat. They make it through the exosphere and thermosphere without much trouble because those layers don’t have much air.

Ans: b

Exp:

Statement 1 is incorrect: The Sun doesn’t heat the whole Earth evenly. That’s why areas near the equator are hot and areas near the poles are cold. So when Earth’s warmer air masses meet cooler air masses, the warmer air rises up higher in the atmosphere while cooler air sinks down to replace the warm air. This movement creates an air current, or wind. A jet stream is a type of air current that forms high in the atmosphere. Earth has four primary jet streams: two polar jet streams, near the north and south poles, and two subtropical jet streams closer to the equator. The primary jet streams only travel from West to East. However, jet streams can move in different ways, creating bulges of winds to the north and south.

Statement 2 is correct: Jet streams are located about five to nine miles above Earth’s surface in the mid to upper troposphere. Aeroplanes also fly in the mid to upper troposphere. So, if an aeroplane flies in a powerful jet stream and they are travelling in the same direction, the aeroplane can get a boost. That’s why an aeroplane flying a route from west to east can generally make the trip faster than an aeroplane travelling the same route east to west.

Statement 3 is correct: Jet streams play a significant role in determining the weather conditions in lower atmosphere. The path followed by temperate cyclones or mid-altitude weather disturbances are largely controlled by these upper circulations. Movement of jet streams is also important in determining prolonged periods of floods or droughts. Jet streams also affect the regularity of monsoonal winds.