JEE Advanced2013PhysicsCapacitanceActual
In the circuit shown in the figure, there are two parallel plate capacitors each of capacitance C . The switch S 1 is pressed first to fully charge the capacitor C 1 and the released. The switch S 2 is then pressed to charge the capacitor C 2 . After some time, S 2 is released and then is S 3 pressed. After some time,
Options
- Athe charge on the upper plate of C 1 is 2CV 0 .
- Bthe charge on the upper plate of C 1 is CV 0 .
- Cthe charge on the upper plate of C 2 is 0.
- Dthe charge on the upper plate of C 2 is - CV 0 .
Correct answer
B. the charge on the upper plate of C 1 is CV 0 .
Step-by-step solution
When S 1 is closed, charge on C 1 = 2 V 0 C After S 2 is closed, half of the change will move to C 2 ∴   charge on C 1 = 1 2 2 V 0 C when S 2 is closed, charge on C 2 = V 0 C but with reversed polarity, ∴   Charge on upper plate = - V 0 C