Q 12-02-073JEE MainJEE Main 2024 (29 Jan, Shift 2)Medium
In the given figure, the charge stored in the $6\ \mu\text{F}$ capacitor, when points $A$ and $B$ are joined by a connecting wire, is ______ $\mu\text{C}$.
Numerical value type. Enter your answer.
Answer: 36
With A and B joined, in steady state current flows 9 V → $6\ \Omega$ → A → B → $3\ \Omega$ → ground (the capacitors carry no current):
$$I = \frac{9}{6 + 3} = 1\ \text{A},\qquad V_A = V_B = 9 - 6 = 3\ \text{V}$$
The $6\ \mu\text{F}$ capacitor is between the 9 V point and B:
$$Q = 6\times(9 - 3) = 36\ \mu\text{C}$$
Solution by Sreeraj P, M.Sc Physics