Q 12-02-182JEE MainJEE Main 2019 (9 Apr, Shift 2)Easy
The parallel combination of two air filled parallel plate capacitors of capacitance $C$ and $nC$ is connected to a battery of voltage, $V$. When the capacitors are fully charged, the battery is removed and after that a dielectric material of dielectric constant $K$ is placed between the two plates of the first capacitor. The new potential difference of the combined system is
Answer: (A) $\dfrac{(n + 1)V}{K + n}$
Total charge (kept after the battery is removed): $Q = (C + nC)V$.
New capacitance of the parallel combination: $KC + nC$.
$$V' = \frac{(n + 1)CV}{(K + n)C} = \frac{(n + 1)V}{K + n}$$
Solution by Sreeraj P, M.Sc Physics