Select the option that is appropriate regarding the following two statements labelled Assertion and Reason. Assertion: A loose, permeable, sandy soil has a higher infiltration capacity than that of a tight, clayey soil. Reason: A soil with poor under-drainage has a higher infiltration capacity.
- ABoth Assertion and Reason are true and Reason is the correct explanation of Assertion.
- BBoth Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- CAssertion is true, but Reason is false.Correct
- DBoth Assertion and Reason are false.
Solution
Concept
Infiltration capacity is high in loose, permeable, well-drained soil and low in tight clayey or poorly drained soil.
Step-by-step solution
1. Loose sandy soil has large pores, so water enters fast. The Assertion is true. 2. Poor under-drainage means water cannot move down, so the soil stays wet and gets saturated. 3. A saturated soil takes in less water, so infiltration capacity becomes lower. The Reason is false. 4. So the answer is C.
Explanation
Sandy, loose soil has big pores and allows water to enter quickly, so its infiltration capacity is high. Poor under-drainage keeps the soil wet and filled with water, which reduces infiltration capacity. So the Assertion is true and the Reason is false.
Why the other options are wrong
A and B: The Reason is false, so both cannot be true. D: The Assertion is true, so this option is wrong.
Shortcut
Good drainage and coarse soil mean high infiltration. Poor drainage and clay mean low infiltration.
Common mistake
Thinking poor drainage keeps water near the surface and so increases infiltration. Actually it reduces it.
Correct answer: C) Assertion is true, but Reason is false.