JEE Physics 2026 Question with Solution

Given: Four statements about capacitance, dielectric behavior, and equipotential surfaces are to be checked.

Find: Which statements are correct, and hence the correct option.

Statement-wise analysis:

For capacitors in series,

$$\frac{1}{C_{\text{eq}}} = \frac{1}{C_1} + \frac{1}{C_2} + \cdots$$

Therefore,

$$C_{\text{eq}} < \min(C_1, C_2, \dots)$$

So statement A is true.

Statement B is false. In a dielectric, free charge does not flow, but bound charges do get displaced slightly due to polarization.

For a parallel plate capacitor,

$$C = \frac{\varepsilon A}{d}$$

Thus, increasing plate area $A$ or decreasing separation/thickness $d$ increases capacitance. So statement C is true.

For a point charge, electric potential depends only on distance $r$:

$$V = \frac{kq}{r}$$

Hence, all points at the same distance from the charge form concentric spherical equipotential surfaces. So statement D is true.

Therefore, the correct statements are A, C and D.

The correct option is D.