Which of the following is a possible application of an $RC$ circuit?

For the $RC$ circuit shown,the resistance is $R = 10.0\ \Omega$,the capacitance is $C = 5.0\ F$ and the battery has voltage $\xi = 12\ V$. The capacitor is initially uncharged when the switch $S$ is closed at time $t = 0$. At some time later,the current in the circuit is $0.50\ A$. What is the magnitude of the charge across the capacitor at that moment (in $C$)?

Given $R_1 = 1\,\Omega$,$C_1 = 2\,\mu F$ and $R_2 = 2\,\Omega$,$C_2 = 4\,\mu F$. The time constants (in $\mu s$) for the circuits $I, II, III$ are respectively:

Under steady state condition, the potential difference across the capacitor in the circuit is . . . . . . $V$.

The charge stored by the capacitor $C$ in the given circuit in the steady state is . . . . . . $\mu C$.

Find the ratio of energy stored in $5\,\mu F$ and $4\,\mu F$ capacitor in the given circuit in steady state.