Calculate the amount of charge on the capacitor of $4\, \mu \text{F}$ in the given circuit. The internal resistance of the battery is $1\, \Omega$. (in $\mu \text{C}$)

When two identical capacitors are charged individually to different potentials and connected in parallel to each other,after disconnecting them from the source:

Three capacitors $A, B$ and $C$ are connected to a battery of $25 \text{ V}$ as shown in the figure. The ratio of charges on capacitors $A, B$ and $C$ will be $-$

$A$ capacitor,$C_1 = 6 \ \mu F$ is charged to a potential difference of $V_0 = 5 \ V$ using a $5 \ V$ battery. The battery is removed and another capacitor,$C_2 = 12 \ \mu F$ is inserted in place of the battery. When the switch $S$ is closed,the charge flows between the capacitors for some time until an equilibrium condition is reached. What are the charges ($q_1$ and $q_2$) on the capacitors $C_1$ and $C_2$ when the equilibrium condition is reached?

Four capacitors are connected in a circuit as shown in the figure. The effective capacitance in $\mu F$ between points $A$ and $B$ will be

The potential difference between the points $P$ and $Q$ in the adjoining circuit will be :-