Question

Which among the following statement(s) is/are TRUE?

• A. Attrition is more dominant in aeolian than in glacial environment.
• B. Centrifugal force drives the sediment-laden water outward when the river channel meanders.
• C. U-shaped valley is a common fluvial geomorphic feature.
• D. The downstream water velocity in a river channel increases upward from the channel bed towards the water surface.

Hint:

U-shaped = glacial; V-shaped = fluvial. Centrifugal force = outer bank erosion; Attrition strongest in wind transport.

Answer 1

The Correct Option is A, B, D

Step 1: Understanding geomorphic processes.
- Attrition: Occurs when particles collide and wear down — more effective in aeolian (wind-blown) environments due to frequent impacts.
- Centrifugal force: In a meandering river, outward-directed centrifugal force causes erosion on the outer bank and deposition on the inner bank.
- U-shaped valleys: Are glacial, not fluvial, features. Fluvial valleys are typically V-shaped.
- Velocity distribution: In rivers, flow velocity increases from the bed upward to the surface and toward mid-channel due to reduced friction.
Step 2: Conclusion.
Hence, the correct statements are (A), (B), and (D).