Q145 / 160 · AP EAMCET 2023 (15 May Shift 1) · Physics
Two thin conducting concentric shells of radii $\mathrm{R}$ and $2 \mathrm{R}$ are shown in the figure. The outer shell carries a charge $+Q$ and the inner shell is neutral. Then the correct statement/s is
(a) When the switch is closed, the potential on the inner shell becomes zero
(b) With the switch closed, the charge on the inner sphere is $\frac{Q}{2}$


- A(a) and (b) are correct
- Correct answerB(a) is correct, (b) is wrong
- C(a) is wrong, (b) is correct
- D(a) and (b) are wrong
Solution
Let charge on inner shell after switch is closed be $q$ then, $\mathrm{V}_{\text {inner }}=\mathrm{V}_{\text {outer }}$
$$
\frac{K q}{R}+\frac{K(Q-q)}{2 R}=\frac{K q}{2 R}+\frac{K(Q-q)}{2 R}
$$
$$
\therefore \mathrm{q}=0
$$
Hence, the correct answer is option: 'B'.