The number of lines of force originating from a point charge of $2 \times 8.85 \times 10^{-9}$ C in a medium of dielectric constant $10$ is ($\epsilon_0 = 8.85 \times 10^{-12}$ SI unit)

The potential difference that must be applied across the parallel and series combination of three identical capacitors such that the energy stored in them becomes the same. The ratio of potential difference in parallel to series combination is

The function of a dielectric in a capacitor is to

Four capacitors are connected to a battery as shown in figure. The ratio of charges on capacitors $C_2$ and $C_4$ is