QUIZ – 2020: INSIGHTS STATIC , 28 June 2021 – Geography – INSIGHTSIAS

Solution: b)

An Aurora is a display of light in the sky predominantly seen in the high latitude regions (Arctic and Antarctic). It is also known as a Polar light.

This is due to a solar flare, which emerged from a Sunspot. The flare is accompanied by a Coronal Mass Ejection (CME) — a large bubble of radiation and particles emitted by the Sun that explodes into space at high speed. This causes the Northern Lights to be visible in more number of areas than usual.

They commonly occur at high northern and southern latitudes, less frequent at mid-latitudes, and seldom seen near the equator.

Effects:

• Auroras affect communication lines, radio lines and power lines.
• It should also be noted here that Sun’s energy, in the form of solar wind, is behind the whole process.

Solution: c)

El Nino is a climatic cycle characterised by high air pressure in the Western Pacific and low air pressure in the eastern.

During this event, there is a warming of the sea surface temperature in the eastern and central equatorial Pacific Ocean.

It is one phase of an alternating cycle known as El Niño Southern Oscillation (ENSO).

While La Niña conditions enhance the rainfall associated with the Southwest monsoon, it has a negative impact on rainfall associated with the Northeast monsoon.

Solution: c)

A mineral is a naturally occurring organic and inorganic substance, having an orderly atomic structure and a definite chemical composition and physical properties. A mineral is composed of two or more elements. But, sometimes single element minerals like sulphur, copper, silver, gold, graphite etc. are found.

The earth’s crust is composed of rocks. A rock is an aggregate of one or more minerals. Rock may be hard or soft and in varied colours. For example, granite is hard, soapstone is soft. Gabbro is black and quartzite can be milky white. Rocks do not have definite composition of mineral constituents. Feldspar and quartz are the most common minerals found in rocks.

Solution: a)

The earth’s surface is being continuously subjected to by external forces originating within the earth’s atmosphere and by internal forces from within the earth. The external forces are known as exogenic forces and the internal forces are known as endogenic forces. The actions of exogenic forces result in wearing down (degradation) of relief/elevations and filling up (aggradation) of basins/ depressions, on the earth’s surface.

The phenomenon of wearing down of relief variations of the surface of the earth through erosion is known as gradation. The endogenic forces continuously elevate or build up parts of the earth’s surface and hence the exogenic processes fail to even out the relief variations of the surface of the earth. So, variations remain as long as the opposing actions of exogenic and endogenic forces continue. In general terms, the endogenic forces are mainly land building forces and the exogenic processes are mainly land wearing forces.

Solution: d)

Weathering processes are responsible for breaking down the rocks into smaller fragments and preparing the way for formation of not only regolith and soils, but also erosion and mass movements.

Biomes and biodiversity are basically a result of forests (vegetation) and forests depend upon the depth of weathering mantles.

Erosion cannot be significant if the rocks are not weathered.

Without weathering taking place, the concentration of the same valuable material may not be sufficient and economically viable to exploit, process and refine since they would be scattered across a large area.

Weathering aids mass wasting, erosion and reduction of relief and changes in landforms are a consequence of erosion.