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

When a resistance of $200\,\Omega$ is connected in series with a galvanometer of resistance G, its range is V. To triple its range, a resistance of $2000\,\Omega$ is connected in series. The value of G is

If a galvanometer is shunted by $\left(\dfrac{1}{n-1}\right)^{th}$ of the value of its resistance, then the fraction of the total current passing through the galvanometer is