UPSC Paper 1 Mock Test - 11 - UPSC MCQ

In the tropical cyclones cumulonimbus clouds with great vertical extent are generated. Nimbus clouds are thick mass of water vapour & rain carrying clouds generally occur as nimbus or in combination of nimbus like cumulonimbus or stratonimbus etc. Cirrus are the highest clouds formed between the altitude of 8 km to 12 km.
Hence, only statement 1 is incorrect.

South Africa lies in the warm temperate zone. But it has a moderate climate due to several reasons. It is surrounded on three sides by oceans. The great height of plateau, on which it lies, is another reason for its cool climate. It is further cooled by the cold ocean current along the west coast.

Stars are formed by the process of Nuclear fusion reaction of hydrogen (four small hydrogen nuclei fuse to produce a bigger helium nucleus and tremendous amount of energy).
Order of surface temperature : Red Stars < White Stars < Blue Stars

Nile river outflows in Mediterranean sea.
Mekong outflows in South China sea.
Refer Atlas.

Igneous rocks are crystalline in structure whereas Sedimentary rocks are non-crystalline in nature.

Stratosphere has higher temperature but the reason is the presence of ozone gas which absorbs the ultraviolet part of incoming solar radiation, raising the temperature. In fact more is the amount of gases in the atmosphere, greater is its heating. It is the reason that near the surface of earth, where the density of atmosphere is maximum the temperature is highest.
Because tropopause is at the height of about 18 km & 8 km at equator & poles respectively, the tropopause temperature above equator is of about - 80 degree centigrade& above poles is - 45 degree centigrade.
Hence, only statement 2 is correct.

The reef-building corals survive best under the following conditions:
1. The water temperature must not fall below 68°F. (20°C). This virtually limits the areal distribution of corals to the tropical, and sub-tropical zones. Again they will not flourish where there are cold currents because of the upwelling of the cold water from the depths that cools the warm surface water. This explains why coral reefs are generally absent on the western coasts of the warm currents, e.g. the Gulf Stream, means that corals are found far to the north of the West Indies in the Atlantic Ocean. The Pacific and the Indian Oceans, however, have the most numerous coral reefs.
2. The depth of the water should not exceed 30 fathoms or 180 feet, because beyond this depth sunlight is too faint for photosynthesis to take place. This is essential for the survival of the microscopic algae, on which the coral polyps depend. Shallow water of less than 100 feet is ideal. But there should always be plenty of water as polyps cannot survive for too long out of water.
3. The water should be saltish and free from sediment. Corals therefore survive best in the moving ocean water well away from the silty coasts or muddy mouths of streams. The corals are best developed on the seaward side of the reef, where constantly moving waves, tides and currents maintain an abundant supply of clear, oxygenated water. They also bring an adequate supply of food in the form of microscopic organisms.

The Ring of Fire is an area where a large number of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. The Ring of Fire is a direct result of plate tectonics and the movement and collisions of lithospheric plates. So option 1 is correct.
Barren Island is located in the Andaman Sea, one of the most easterly of the Andaman Islands. It is the only confirmed active volcanoin South Asia. So option 2 is correct.

Temperature and Humidity also plays a large role but RAINFALL is the MAIN factor
Tropical evergreen forests: This type of vegetation is found in areas where rainfall is above 250 cms and temperature ranges between 25^°C and 27^°C. Since the trees are always green they are called evergreen forests. The heavy rainfall, high temperature and humidity are responsible for the growth of these dense forests. The trees grow about 60 mts. high. The branches of trees form a canopy and prevent the sun's rays from reaching the ground. In India, most of these forests are found on the western side of the Western Ghats,in the North-Eastern hills and the Andaman and Nicobar islands. The semi evergreen forests are found in the lower rainfall areas of the Western Ghats, Orissa and West Bengal. Ebony, mahogany, rose-wood and rubber are the important trees. Bamboo bushes are also found.

In Eurasia temperate grasslands which are known as steppe are quite extensive. These stretch eastward from the shores of Black sea across great Russian plain to the foothills of Altai mountain. In north America also Prairies are quite extensive in comparison to Pampas and Downs. So option 1 is correct.
Temperate grasslands in Australia are known as Downs. So option 2 is correct.
Due to continentality climate in temperate grasslands has extremely hot summer and very cold winters. But in southern hemisphere due to effect of sea climate is not so extreme. So option 3 is correct.

The earth rotates 360° in about 24 hours, which means 15° an hour or 1° in four minutes. Thus, when it is 12 noon at Greenwich, the time at 15° east of Greenwich will be 15 x 4 = 60 minutes, i.e., 1 hour ahead of Greenwich time, which means 1 p.m. Similarly the time gap between Greenwich and 142 ½^° latitude is 9 hours and 30 minutes. When it is 4 pm at Greenwich, the time at 142 ½^° latitude will be 1:30 am next day i.e Monday.

Chota Nagpur region gets rainfall due to Arabian Sea branch as well. The winds flow through the rift valley between Vindhyas & Satpura & cause rainfall over the plateau.
Position of Equatorial jet stream along eastern coast of Africa is one of the many factors that impact the distribution & intensity of Monsoon in India. Hence, statement 3 is correct.

Hess argued that constant eruptions at the crest of oceanic ridges cause the rupture of the oceanic crust and the new lava wedges into it, pushing the oceanic crust on either side. The ocean floor, thus spreads.
The younger age of the oceanic crust as well as the fact that the spreading of one ocean does not cause the shrinking of the other, made Hess think about the consumption of the oceanic crust. He further maintained that the ocean floor that gets pushed due to volcanic eruptions at the crest, sinks down at the oceanic trenches and gets consumed.

Continental Plateaus rise abruptly from the lowlands or the sea. Piedmont Plateaus are called plateaus of denudation as areas which were high formerly have now been reduced by erosion. Third statement applies for Intermontane plateaus.

Those that have been known to errupt and show signs of possible erruption in future are dormant volcanoes. Other statements are correct.

Table showing permanent gases of the earth’s atmosphere 

The greater part (NOT the entire part) of South America lies within the tropical zone.
Campos and Llanos are tropical grasslands found in South America.

Black Hole is formed from a very massive neutron star.
The presence of a black hole can be felt by the effect of its gravitational field on its neighbouring objects in the sky. e.g. – if a star moves in a circle without any visible star in the centre we can conclude there’s a black hole in the centre. 

Earth’s distinct seasons are produced by interactions of revolution (annual orbit about the Sun) and rotation (Earth’s turning on its axis).
As Earth rotates, the boundary that divides daylight and darkness is the circle of illumination.
Other reasons for seasons include axial tilt (at about 23.5° from a perpendicular to the plane of the ecliptic), axial parallelism (the parallel alignment of the axis throughout the year), and sphericity (appears as an spheroid to the Sun’s parallel rays; the geoid).

Gentle slope which start at the mountain foot reduces the speed of running water and heavy load of sediments could not be carried further.

River capture is back-cutting (head ward erosion) which happens in the Upper course. Oxbow lakes are formed in the Lower course. It applies for the Middle course.

If you are in an open ground then it is better to sit on the floor as it will reduce your area and can prevent you from lightening. Lightening conductor is a rod longer than the house and some part of it is above the roof.

Temperature controls density of seawater through the phenomenon of thermal expansion. Pressure controls through compressive effects. And, Salinity affects through addition of dissolved substances.

All statements are correct.

The climate history preserved within layers of sediments that slowly accumulate on the bottoms of lakes and oceans can span hundreds of millions of years or longer. The resolution of these records is variable; it may be annual or on the order of a century or millennium. Sequences of sediments that are currently at the bottom of lakes or on the ocean floor are used to interpret climates of the recent past
Rocks preserved on the continents that are thousands, millions, hundreds of millions, or even billions of years old are used to interpret the much more distant past.

Both Steppe and Prairies are temperate grasslands.

Single element minerals like sulphur, copper, silver are also found.

Vertical pressure gradient is much larger than horizontal pressure gradient, but strong verticals current are not observed because the pressure gradient force is balanced by the downward gravitational force.
Near the surface air is heated due to conduction, while at some height the air is heated due to convection of air where cold air from top moves down and gets heated by coming in contact with earth & then moves up & the cycle continues.
Because of presence of the continuous oceans in the southern hemisphere it has more continuous isobars, while in north the continuity is broken due to alternate presence of land & water