What physical quantities may $X$ and $Y$ represent? ($Y$ represents the first mentioned quantity)

As shown in the figure,what will be the charge on each capacitor and the potential difference across each,respectively?

$A$ part of a circuit is shown in the figure. If $V_A - V_B = 4 \, V$,then find the charge on the $4 \, \mu F$ capacitor connected to point $A$. (in $, \mu C$)

In the given circuit,what are the electric potentials at points $A$ and $B$?

$512$ identical drops of mercury are charged to a potential of $2 \ V$ each. The drops are joined to form a single drop. The potential of this drop is ......... $V.$

$A$ capacitor $C_1 = 1.0 \, \mu F$ is charged up to a voltage $V = 60 \, V$ by connecting it to a battery $B$ through switch $(1)$. Now,$C_1$ is disconnected from the battery and connected to a circuit consisting of two uncharged capacitors $C_2 = 3.0 \, \mu F$ and $C_3 = 6.0 \, \mu F$ in series through a switch $(2)$ as shown in the figure. The sum of the final charges on $C_2$ and $C_3$ is ...... $\mu C$.