Question

Assertion (A): In constant potential region, electric field is zero. Reason (R): From Gauss’s Law, zero electric field means zero enclosed charge.

• A. Both (A) and (R) are true, (R) explains (A)
• B. Both (A) and (R) are true, (R) does not explain (A)
• C. (A) true, (R) false
• D. (A) false, (R) true

Hint:

Constant potential implies zero electric field. Zero field implies zero enclosed charge by Gauss's law.

Answer 1

The Correct Option is A

In a region of constant potential, \( E = -\nabla V = 0 \). From Gauss’s law: \[ \oint \vec{E} \cdot d\vec{A} = \frac{q_{\text{in}}}{\varepsilon_0} \Rightarrow \vec{E} = 0 \Rightarrow q_{\text{in}} = 0 \] So, both A and R are true and R correctly explains A.