Daily Quiz: UPSC Prelims Marathon – January 12, 2018

Statement 1 is correct. Fly ash will be used to make bricks, blocks, tiles, wall panels, cement and other construction materials. Its Agricultural uses are soil amendment, fertilizer, cattle feeders, soil stabilization in stock feed yards, and agricultural stakes.

Statement 2 is correct. Fly ash is one of the coal combustion products, composed of the fine particles that are driven out of the boiler with the flue gases.

Statement 3 is incorrect. Constituents of fly ash can be, Arsenic, beryllium, boron, cadmium, chromium, hexavalent chromium, cobalt, lead, manganese, mercury, molybdenum, selenium, strontium, thallium, and vanadium. Its negatively impacts in the environment are, depositing over snow, thus reducing the albedo and initiating melting. In India Himalayan ecology in particular is adversely impacted by fly ash.

Statement 1 is incorrect. They do not shed their leaves at a time and therefore always remain green and are called evergreen forest.

Statement 2 is correct. In dry regions where there is scarcity of water leaf size becomes smaller so that the portion exposed to the sun is lesser and transpiration is lesser. 

Statement 3 is incorrect. Tropical Evergreen forests indicate a climate with year-round adequate rainfall.

Statement 1 is incorrect. The undergrowth in some areas of a rainforest can be restricted by poor penetration of sunlight to ground level. A tropical rainforest typically has a number of layers, each with different plants and animals adapted for life in that particular area.

Statement 2 is incorrect.The nature of vegetation in the world changes according to, latitude, altitude, climate, nature of soil and also many other factors.

Statement 3 is correct. Tree growth in savanna is controlled by the nearness of the water table, with trees always along water bodies, grading into gallery forest, which in turn may be vegetative comparable to dry forests or rainforests of the area. The vegetation in savanna also determined by periodic fires.

Due to very high temperature and pressure at the solar core, hydrogen atoms fuse to form helium atoms, resulting in generation of very huge quantity of fusion energy that finds its way to sun’s surface.

Sideral day  is the time between two consecutive transits of the First Point of Aries. It represents the time taken by the earth to rotate on its axis relative to the stars, and is almost four minutes shorter than the solar day because of the earth’s orbital motion.  Solar Day- Because of the Earth’s revolution, a solar day is slightly longer than a sidereal day.

All the above statements are correct.

A white dwarf is what stars like the Sun become after they have exhausted their nuclear fuel. Near the end of its nuclear burning stage, this type of star expels most of its outer material, creating a planetary nebula. Only the hot core of the star remains.

A black hole is a place in space where gravity pulls so much that even light cannot get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, people can’t see black holes. Space telescopes can help find black holes.

Sometimes a sudden, rapid, and intense variation in brightness is seen on the Sun. That is a solar flare. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. A solar flare contains high energy photons and particles, and is released from the Sun in a relatively short amount of time .

Sial refers to the earth’s crusts upper layer, Sima is the earth’s crusts lower layer .While Sial makes up a majority of the continental crust, the oceanic crust is primarily composed of Sima.

The continents are composed of lighter silicates—silica + aluminium (also called ‘sial’) while the oceans have the heavier silicates—silica + magnesium (also called ‘sima’).

Core Lies between 2900 km and 6400 km below the earth’s surface.  It is composed of nickel and iron called NiFe.