Three capacitors $C_1$, $C_2$ and $C_3$ are connected to voltage source V as shown in figure. The voltage across $C_3$ will be

Two capacitors, $C_1$ and $C_2$ have their capacitances in the ratio 1:2. $V_s$ and $V_p$ are the potential differences applied across the series and parallel combination of $C_1$ and $C_2$ respectively, so that the energy stored in the two cases becomes same. The ratio $V_s$ to $V_p$ is

A capacitor has capacity C when it's parallel plates are separated by air medium of thickness 'd'. A slab of material of dielectric constant K having area equal to that of plates but thickness $\dfrac{d}{2}$ is inserted between the plates. Capacitance of the capacitor in the presence of slab will be

The electric field between the plates of a parallel plate capacitor is 'E'. If the charge on the plates is Q then the force on each plate is