The potential difference across the $4 \mu F$ capacitor in series with the parallel combination in the following circuit is: (in $V$)

Find the equivalent capacitance across points $A$ and $B$.

In the adjoining figure, the potential difference between $X$ and $Y$ is $60 \ V$. The potential difference between the points $M$ and $N$ will be: (in $V$)

The equivalent capacitance between points $A$ and $B$ is

An electrical technician requires a capacitance of $2 \; \mu F$ in a circuit across a potential difference of $1 \; kV$. $A$ large number of $1 \; \mu F$ capacitors are available,each of which can withstand a potential difference of not more than $400 \; V$. Suggest a possible arrangement that requires the minimum number of capacitors.

Two capacitors of capacities $2 \mu F$ and $4 \mu F$ are connected in parallel. $A$ third capacitor of $6 \mu F$ capacity is connected in series with this combination. $A$ battery of $12 \text{ V}$ is connected across this combination. The charge on the $2 \mu F$ capacitor is: (in $\mu C$)