Q108 / 150 · MHT CET 2025 (27 Apr Shift 2) · Physics
Two conducting spheres of radii ' $r_1$ ' and ' $r_2$ ' are equally charged. The ratio of their potentials is (potential of $r_1$ to potential $r_2$ )
- Correct answerA$\frac{r_1^2}{r_2^2}$
- B$\frac{r_2^2}{r_1^2}$
- C$\frac{r_1}{r_2}$
- D$\frac{r_2}{r_1}$
Solution
The potential of a conducting sphere with charge $Q$ and radius $r$ is $V = \frac{1}{4\pi\epsilon_0} \frac{Q}{r}$.
After charging disconnected identical spheres to equal potential and reconnecting them, both spheres share the same charge $Q$.
The ratio of the potentials becomes $\frac{V_1}{V_2} = \frac{\frac{Q}{r_1}}{\frac{Q}{r_2}} = \frac{r_2}{r_1}$.
The correct choice is D.
Hence, the correct answer is option: 'A'.