Daily Quiz: UPSC Prelims Marathon – August 31, 2018

Statement 1 is correct.

The direction of the slope and its angle control the amount of solar radiation received locally. Slopes more exposed to the sun receive more solar radiation than those away from the sun’s direct rays. Whether in the northern hemisphere or southern hemisphere, differences exist between north- and south-facing slopes, although the differences are reversed between the hemispheres.

In middle latitudes, the south facing slopes exposed to sunlight have different conditions of vegetation and soils and the north facing slopes with cool, moist conditions have some other soils and vegetation.

Statement 2 is incorrect.

Dry climates are more prone to desilication. Removal of silica from the soil is known as desilication. In dry climates, because of high temperature, evaporation exceeds precipitation and hence ground water is brought up to the surface by capillary action and in the process the water evaporates leaving behind salts in the soil. Such salts form into a crust in the soil known as hardpans. In tropical climates and in areas with intermediate precipitation conditions, calcium carbonate nodules (kanker) are formed.

Statement 1 is correct.

Snowline is the boundary on a mountain beyond which there is perpetual (permanent) snow. It depends mainly on two factors – altitude and the amount of precipitation.

Statement 2 is correct.

The river hagirathi is mainly fed by meltwaters from under the snouut (Gaumukh) of the Gangoti glacier. Alkapuri glacier feeds waters to Alakananda River. Rivers Alkananda and Bhagirathi join to make river Ganga near Devprayag.

Statement 3 is correct.

Higher temperatures and less snowfall have been causing many glaciers around the world to retreat recently. Glaciers retreat when their terminus does not extend as far downvalley as it previously did. Glaciers may retreat when their ice melts or ablates more quickly than snowfall can accumulate and form new glacial ice.

All the rivers(Iguazu River, Congo River and Naf River) form international border between two countries. Iguazu River: Border between Brazil and Argentina.

Congo River: Border between Democratic Republic of Congo and Republic of Congo  Naf River: The Naf River is an international river marking the border of southeastern Bangladesh and western Myanmar.

Statement 1 is correct.

The Southern slopes in Himalayan region are covered with thick vegetation, while the northen slopes are generally barren. Himalayas are oriented east-west and their southern slopes are in direct sunshine for a larger part of the year so the snowline on the southern slopes of the ridges is higher than the northern slopes.

Statement 2 is incorrect.

Volume of precipitation decreases from the south towards the north, therefore southern ranges in eastern Himalayas have lower snowline than the northern ranges.

Statement 3 is correct.

Volume of precipitation increases with altitude. However, Ladakh is in a rain-shadow region and so don’t receive monsoon winds thereby summer is dry but whatever little precipitation occurs is in the form of snowfall during freezing winter months.

Statement c is incorrect.

India is the third largest producer and exporter of cashew in the world next only to Vietnam and Nigeria.

Statements a, b and d are correct.

Statement 1 is correct.

A coral reef is made of thin layers of calcium carbonate. Coral polyps form a living mat over a calcium carbonate skeleton. Stony corals (or scleractinians) are the corals primarily responsible for laying the foundations of, and building up, reef structures. Massive reef structures are formed when each individual stony coral organism—or polyp—secretes a skeleton of calcium carbonate.

Statement 2 is correct.

Coral reefs occur in tropical regions where the mean surface temperature is above 20°C.Coral reefs are either restricted or absent from along the west coast of the Americas, as well as the west coast of Africa. This is due primarily to upwelling and strong cold coastal currents that reduce water temperatures in these areas (Nybakken, 1997). Reefs are also restricted along the coast around north-eastern South America and Bangladesh due to the release of vast quanities of freshwater from the Amazon and GAnges Rivers respectively.

Statement 3 is correct.

Worldwide there are about 800 reef building species. These species are not evenly spread over the tropics. The “Indo-Malayan triangle” accounts for 600 of them, this area is referenced as the “Coral triangle” or the “Center of marine biodiversity”.

Mediterranean climate is found between the 30o- 45oN-S latitudes & gets its name from the climate found around the Mediterranean Sea.

The basic cause of this type of climate is shifting of the wind belts with summers – warm to hot, and winters – cool but mild.

These regions have also been called ‘winter-rain & summer dry’.