In the circuit shown in Fig., C1 = 2C2. Initially, capacitor C1 is charged to a potential of V. The current in the circuit just after the switch S is closed is

Uncharged capacitor behaves as a short circuit just after closing the switch. But charged capacitor behaves as the battery of emf V just after closing the switch. Therefore,I=q0C1(2R)=q02RC1=V2R