Which one of the following is likely to be the most prevalent form of weathering in hot-tropical desert areas?
- A.Mechanical
- B.Chemical
- C.Biological
- D.Leaching
Correct answer
Explanation
The correct answer is A, Mechanical. Hot deserts have a large daily range of temperature and very little moisture, so rocks break up physically rather than decay chemically.
In a hot desert the rock surface heats up strongly by day and cools quickly at night under clear skies. The outer layers expand and contract more than the interior, and different minerals expand at different rates, so the rock cracks, flakes off in sheets (exfoliation) or crumbles grain by grain (granular disintegration). Salt crystals growing in cracks add to the breaking. Because there is hardly any water and little plant life, the reactions and organisms that cause other kinds of weathering are weak.
B is wrong because chemical weathering needs water and warmth together and is strongest in hot, humid equatorial regions. C is wrong because biological weathering depends on plants, roots and burrowing animals, which are scarce in deserts. D is wrong because leaching is the washing down of soluble minerals by heavy rain.
Exam tip: Hot deserts mean mechanical weathering and exfoliation; hot and humid tropics mean chemical weathering.
Practice Questions
View allBagram Air Base is located in
- A.Turkey
- B.Pakistan
- C.Afghanistan
- D.Israel
Show answer
Bagram Air Base lies in Parwan province of Afghanistan, about 60 km north of the capital Kabul.
Read the full explanation →Which one of the following statements is not correct?
- A.Position of the Sun, Earth and Moon in a straight line of 180° angle is known as syzygy.
- B.Syzygy conjunction causes solar eclipse.
- C.Syzygy opposition causes lunar eclipse.
- D.Syzygy conjunction occurs at the time of perihelion only.
Show answer
This statement is not correct, because conjunction happens at every new moon, about once a month, and has nothing to do with the Earth's closest point to the Sun.
Read the full explanation →Which one of the following about sugar industry of Peninsular India is not correct?
- A.High yield per hectare of sugarcane
- B.Higher sucrose content
- C.Long crushing season
- D.Most of the mills in the Peninsula are located mainly along the east coast
Show answer
This statement is not correct, because the peninsular sugar mills are concentrated mainly in Maharashtra and Karnataka, in the west and the interior of the plateau.
Read the full explanation →Which of the following statements is/are correct?
1. Visakhapatnam Port is a land-locked harbour.
2. Deendayal Port is a tidal port.
Select the correct answer using the code given below.
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
Show answer
Both statements describe the two ports correctly. Visakhapatnam in Andhra Pradesh is India's deepest land-locked and protected port on the east coast.
Read the full explanation →Weathering, mass wasting, erosion and transportation are indicators of which one of the following processes?
- A.Denudation
- B.Endogenetic process
- C.Diastrophism
- D.Mountain building
Show answer
Weathering, mass wasting, erosion and transportation together wear down and strip away the earth's surface, and this combined work is called denudation.
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