(DAYS LEFT FOR THE UPSC CIVIL PRE EXAM: 107)
1. Consider the following:
2. Convergent plate boundaries
3. Volcanic activity
Which of the following rocks is often associated with the above?
B. Rock Salt
D. Bituminous coal
Answer 1 —
Solution : A
1. Gneiss usually forms by regional metamorphism at convergent plate boundaries. It is a
high-grade metamorphic rock in which mineral grains recrystallized under intense heat and
pressure associated with mountain building and volcanic activity.
This alteration increases the size of the mineral grains and segregated them into bands, a
transformation which made the rock and its minerals more stable in their metamorphic
2. Gneiss can form in several different ways. The most common path begins with shale, which is a
3. Regional metamorphism can transform shale into slate, then phyllite, then schist,
and finally into gneiss.
Question 2 —
Among the following, which of these areas is least susceptible to landslides?
A. Undulated reliefs of Aravali
B. Young mountainous regions of Himalayas
C. Windward sides of Western Ghats
D. Areas near Khasi hills that experience frequent rainfall
Answer 2 —
1. Two major categories of landslide prone regions can be established – high and low
2. Highly unstable, relatively young mountainous areas in the Himalayas and Andaman and Nicobar,
high rainfall regions with steep slopes in the Western Ghats and Nilgiris, the north-eastern regions,
along with areas that experience frequent ground-shaking due to earthquakes, etc. and areas of
intense human activities, particularly those related to construction of roads, dams, etc. are included
in the high risk zone.
3. Moderate to Low Vulnerability Zone : Areas that receive less precipitation such as Trans-Himalayan
areas of Ladakh and Spiti (Himachal Pradesh), undulated yet stable relief and low precipitation
areas in the Aravali (with stable rock structures), rain shadow areas in the Western and Eastern
Ghats and Deccan plateau also experience occasional landslides.
4. The remaining parts of India, particularly states like Rajasthan, Haryana, Uttar Pradesh, Bihar,
West Bengal (except district Darjiling), Assam (except district Karbi Anglong) and Coastal regions of
the southern States are safe as far as landslides are concerned.
Question 3 —
Consider the following: Tropical cyclones are
1. intense low-pressure areas
2. largely confined to the areas lying between 5° N and 5° S latitudes
3. like a heat engine that is energised by the release of latent heat on account of the condensation of
Select the correct answer using the codes below.
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 2 and 3 only
Answer 3 —
1. Statement 2: They lie between 30° N and 30° S latitudes, in the atmosphere around
which high velocity winds blow. They are not found close to the equator where the Coriolis force is
2. Horizontally, it extends up to 500-1,000 km and vertically from surface to 12-14 km.
3. Statement 3: A tropical cyclone or hurricane is like a heat engine that is energised by the release of
latent heat on account of the condensation of moisture that the wind gathers after moving over the
oceans and seas
4. Tropical cyclones are characterised by large pressure gradients. The centre of the cyclone is mostly
a warm and low-pressure, cloudless core known as eye of the storm.
Question 4 –.
Floods can be caused due to
1. Carrying capacity of the river channels exceeding the surface run-off
2. Considerable reduction in the infiltration rate of soil in regions of high rainfall
Which of the above is/are correct?
A. 1 only
B. 2 only
C. Both 1 and 2
Answer 4 –.
1. Floods are relatively slow in occurrences and often, occur in well-identified regions
and within expected time in a year.
2. Floods occur commonly when water in the form of surface run-off exceeds the carrying capacity of
the river channels and streams and flows into the neighbouring low-lying flood plains.
At times, this even goes beyond the capacity of lakes and other inland water bodies in which they
3. Floods can also be caused due to a storm surge (in the coastal areas), high intensity rainfall for a
considerably longer time period, melting of ice and snow, reduction in the infiltration rate and
presence of eroded material in the water due to higher rate of soil erosion.