Q 12-02-134JEE MainJEE Main 2021 (31 Aug, Shift 1)Medium
A capacitor of $50\ \mu\text{F}$ is connected in a circuit as shown in figure. The charge on the upper plate of the capacitor is ______ $\mu$C.
Numerical value type. Enter your answer.
Answer: 100
In steady state no current flows into the capacitor. Current through the three resistors: $I = \dfrac{6}{6\ \text{k}\Omega} = 1$ mA.
The capacitor is across the lowest $2\ \text{k}\Omega$ resistor: $V_C = 1\ \text{mA}\times2\ \text{k}\Omega = 2$ V, with the upper plate at the higher potential.
$Q = CV = 50\times2 = 100\ \mu\text{C}$.
Solution by Sreeraj P, M.Sc Physics