Select the option that is appropriate regarding the following two statements labelled Assertion and Reason. Assertion: Due to the inherent nature of various parameters involved in the process, the yield from a catchment is a random variable. Reason: The yield from a catchment is the end-product of various processes such as precipitation, infiltration and evapotranspiration operating on the catchment.
- ABoth Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- BBoth Assertion and Reason are true and Reason is the correct explanation of Assertion.Correct
- CBoth Assertion and Reason are false.
- DAssertion is true, but Reason is false.
Solution
Concept
Catchment yield is the result of many random hydrological processes, so the yield itself is a random variable.
Step-by-step solution
1. Yield of a catchment = total runoff volume available over a period. 2. Yield depends on precipitation, infiltration and evapotranspiration acting on the catchment. 3. These processes vary randomly in time and space. 4. So the yield is also a random variable. The Assertion is true. 5. The Reason is true, and it explains why the yield is random. 6. Answer: B.
Explanation
The yield of a catchment comes from many processes like rainfall, infiltration and evapotranspiration. These processes are random in nature, so the final yield is also random. So both statements are true, and the Reason correctly explains the Assertion.
Why the other options are wrong
A: The Reason does explain the Assertion. C: Both statements are true. D: The Reason is also true.
Shortcut
Random inputs (rain, losses) give a random output (yield). The Reason directly explains the Assertion.
Common mistake
Choosing A by thinking the Reason only describes yield and does not explain why it is random.
Correct answer: B) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.