Question

A circuit is connected as shown in the figure with the switch S open. When the switch is closed, the total amount of charge that flows from Y to X is(a) 0(b) 54 μC(c) 27 μC(d) 81 μC

Answer 1

answer : option (C) 27μC

explanation : when switch is closed, then 3 ohm and 6ohm are in series. steady state potential difference across 6μF capacitor = potential difference across 6 ohm resistor = 9V × 6/(3 + 6) = 6V

charge on 6μF capacitor = 6V × 6μF = 36μC

Similarly, potential difference across 3μF capacitor = potential difference across 3 ohm resistor = 9 × 3/(3 + 6) = 3V

charge on 3μF capacitor = 3V × 3μF = 9μC.

The charge distribution on each plate of capacitor is shown in figure. Now total charge on the plates marked (2) and marked (3) is -9μC + 36μC = 27μC

hence, 27μC charge flows from Y to X.

Answer 2

Option C is correct.

27 μC.