BITSAT2015PhysicsCapacitanceActual
A parallel plate capacitor of capacitance C is connected to a battery and is charged to a potential difference V . Another capacitor of capacitance 2 C is similarly charge to a potential difference 2 ~V . The charging battery is now disconnected and the capacitors are connected in parallel to each other in such a way that the positive terminal of one is connected to the negative terminal of the other. The final energ
Options
- AZero
- B3 2 CV ²
- C25 6 CV ²
- D9 2 CV ²
Correct answer
B. 3 2 CV ²
Step-by-step solution
From the figure. The net charge shared between the capacitors Q^ =Q₂-Q₂=4 C V-C V=3 C V The two capacitors will have some potential, say V ^ . The net capacitance of the parallel combination of the two capacitors C^ =C₁+C₂=C+2 C+3 C The potential of the capacitors V ^ = Q ^ C ^ = 3 CV 3 C = V The electrostatic energy of the capacitors E ^ = 1 2 C ^ V ^ 2 = 1 2 (3 C ) V ²= 3 2 CV ²