Question

Assertion (A): The effective rainfall erosion index of a given area is linearly proportional to the percentage of ground that is not covered by vegetation.
Reason (R): The rain erosion index includes both the kinetic energy of rain and the maximum 30-minute rain intensity.

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A).
• B. Both (A) and (R) are correct but (R) is NOT the correct explanation of (A).
• C. (A) is correct but (R) is not correct.
• D. (A) is not correct but (R) is correct.

Hint:

Always evaluate logical connections in assertion-reason type questions independently of correctness.

Answer 1

The Correct Option is B

Step 1: R factor (rain erosion index) = kinetic energy times maximum 30-min intensity, purely climatic, so (R) is true.
Step 2: Soil loss rises linearly with percentage bare ground for a given storm, so (A) is also true.
Step 3: Since vegetation cover is not part of the erosivity formula in (R), it cannot explain (A).
Correct option: Both (A) and (R) are correct but (R) is NOT the correct explanation of (A).