Question

Assertion A: The distance from the centre of the well to the outer limit of the cone of depression is known as radius of influence.
Reason R: Radius of influence depends on the pumping rate, length of pumping period, aquifer characteristics, slope of the water table and recharge in the zone of influence of the well.
In light of the above statements, choose the most appropriate answer from the options given below:

• 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:

Radius of influence increases with:
- Higher pumping rate
- Longer pumping period
- Lower aquifer transmissivity

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
When water is pumped from a well, the water table forms a cone of depression.
The radius of influence is the extent of this cone.

Step 2: Key Formula or Approach:
No specific formula.
Need to understand the concept of radius of influence.

Step 3: Detailed Explanation:
The radius of influence is indeed the distance from the centre of the well to the outer limit of the cone of depression.
This is the definition given in A, which is correct.
The radius of influence depends on various factors:
- Pumping rate
- Length of pumping period
- Aquifer characteristics
- Slope of the water table
- Recharge in the zone of influence
These factors determine how far the cone of depression extends.
Thus, R is also correct and explains A.

Step 4: Final Answer:
Both A and R are correct, and R is the correct explanation of A.
Hence, the correct option is (A).