In the circuit shown,when the key $K$ is pressed at time $t = 0$,which of the following statements about current $I$ in the resistor $AB$ is true?

$A$ capacitor of $8 \mu\text{F}$ is connected as shown in the circuit. Find the charge on the plates of the capacitor. (in $\mu\text{C}$)

$A$ combination of two identical capacitors, a resistor $R$, and a $DC$ voltage source of voltage $6\; V$ is used in an experiment on a $C-R$ circuit. It is found that for a parallel combination of the capacitors, the time in which the voltage of the fully charged combination reduces to half its original voltage is $10\; s$. For a series combination, the time needed for reducing the voltage of the fully charged series combination by half is: (in $; s$)

In the given circuit,switch $S$ is closed at $t = 0$. The current $I$ in the figure at time $t$ is

After the switch shown in Figure $A$ is closed,there is a current $i$ through the resistance $R$. Figure $B$ indicates current variation curves $a, b, c,$ and $d$ for four sets of values of $R$ and capacitance $C$:
$(i)$ $R_0$ and $C_0$
$(ii)$ $2R_0$ and $C_0$
$(iii)$ $R_0$ and $2C_0$
$(iv)$ $2R_0$ and $2C_0$
Which set goes with which curve?

The circuit shown in the figure consists of a charged capacitor of capacity $3\, \mu F$ and a charge of $30\, \mu C$. At time $t = 0,$ when the key is closed,the value of current flowing through the $5\, M\Omega$ resistor is $'x'\, \mu A$. The value of $'x'$ to the nearest integer is .........