Microtheme: Geomorphology —
8 questions asked in Prelims in the past.

1. [2026] Consider the following assertion:
   In the Pleistocene period either the Yamuna once flowed into the Indus, or the Sutlej flowed into the Yamuna and one major tributary of either had shifted from the Ganga to the Indus or vice versa.
   Which of the following is/are the basis of the above assertion?
   1. The Nadi-Sukta of the Rigveda
   2. The explorations of the Sutlej and the Yamuna by Robert Bruce Foote
   3. The presence of the same species of dolphins in both the Indus and the Ganga river systems
   • (a) 1 only
   • (b) 2 only
   • (c) 1 and 2
   • (d) 3 only
   Correct Answer: (D) 3 only
2. [2026] Which of the following geographical features or phenomena is/are associated with the Peninsular Block of India?
   1. Submergence of parts of the western coast due to tectonic activity
   2. Presence of residual mountain ranges such as the Veliconda hills and Mahendragiri hills
   3. Deep, V-shaped river valleys formed by fast-flowing rivers
   • (a) 1 only
   • (b) 1 and 2
   • (c) 2 and 3
   • (d) 3 only
   Correct Answer: (B) 1 and 2
3. [2025] Consider the following statements:
   Statement I:
   In the context of effect of water on rocks, chalk is known as a very permeable rock, whereas clay is known as quite an impermeable or least permeable rock.
   Statement II:
   Chalk is porous and hence can absorb water.
   Statement III:
   Clay is not at all porous.
   Which one of the following is correct in respect of the above statements?
   • (a) Both Statement II and Statement III are correct and both of them explain Statement I
   • (b) Both Statement II and Statement III are correct but only one of them explains Statement I
   • (c) Only one of the Statements II and III is correct and that explains Statement I
   • (d) Neither Statement II nor Statement III is correct
   Correct Answer: (C) Only one of the Statements II and III is correct and that explains Statement I
4. [2025] Which of the following are the evidences of the phenomenon of continental drift?
   I. The belt of ancient rocks from Brazil coast matches with those from Western Africa.
   II. The gold deposits of Ghana are derived from the Brazil plateau when the two continents
   lay side by side.
   III. The Gondwana system of sediments from India is known to have its counterparts in six
   different landmasses of the Southern Hemisphere.
   Select the correct answer using the code given below:
   • (a) I and III only
   • (b) I and II only
   • (c) I, II and III
   • (d) II and III only
   Correct Answer: (C) I, II and III
5. [2024] Consider the following statements:
   Statement-I:
   Rainfall is one of the reasons for weathering of rocks.
   Statement-II:
   Rain water contains carbon dioxide in solution.
   Statement-III:
   Rain water contains atmospheric oxygen.
   Which one of the following is correct in respect of the above statements?
   • (a) Both Statement-II and Statement-III are correct and both of them explain Statement-I*
   • (b) Both Statement-II and Statement-III are correct, but only one of them explains Statement-I
   • (c) Only one of the Statements II and III is correct and that explains Statement-I
   • (d) Neither Statement-II nor Statement-III is correct
   Correct Answer: (A) Both Statement-II and Statement-III are correct and both of them explain Statement-I*
6. [2023] Consider the following statements:
   1. In a seismograph, P waves are recorded earlier than S waves.
   2. In P waves, the individual particles vibrate to and fro in the direction of waves propogation whereas in S waves, the particles vibrate up and down at right angles to the direction of wave propagation.
   Which of the statements given above is/are correct?
   • (a) 1 only
   • (b) 2 only
   • (c) Both 1 and 2
   • (d) Neither 1 nor 2
   Correct Answer: (C) Both 1 and 2
7. [2021] In case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrient to enter
   the cycle?
   • (a) Carbon cycle
   • (b) Nitrogen cycle
   • (c) Phosphorus cycle
   • (d) Sulphur cycle
   Correct Answer: (C) Phosphorus cycle
8. [2009] In the structure of planet Earth, below the mantle, the core is mainly made up of which one of the following ?
   • (a) Aluminium
   • (b) Chromium
   • (c) Iron
   • (d) Silicon
   Correct Answer: (C) Iron