In the given circuit,a charge of $+80 \ \mu C$ is given to the upper plate of the $4 \ \mu F$ capacitor. Then in the steady state,the charge on the upper plate of the $3 \ \mu F$ capacitor is:

Seven capacitors,each of capacitance $2\,\mu F$,are to be connected in a configuration to obtain an effective capacitance of $\left( \frac{6}{13} \right)\,\mu F$. Which of the combinations,shown in figures below,will achieve the desired value?

Assertion $(A)$: Two condensers of same capacity are connected first in parallel and then in series. The ratio of resultant capacities in the two cases will be $4: 1$.
Reason $(R)$: In parallel,capacity increases and in series,capacity decreases.

In the given circuit,what is the potential difference across the $4.5\ \mu F$ capacitor in $V$?

Consider the combination of $2$ capacitors $C_{1}$ and $C_{2}$,with $C_{2} > C_{1}$. When connected in parallel,the equivalent capacitance is $\frac{15}{4}$ times the equivalent capacitance of the same capacitors connected in series. Calculate the ratio of the capacitors,$\frac{C_{2}}{C_{1}}$.

Which of the following combinations of $7$ identical capacitors each of $2 \mu F$ gives a resultant capacitance of $\frac{10}{11} \mu F$?