The capacity of a pure capacitor is $1 \, F$. In $DC$ circuits,its effective resistance will be

$A$ filter circuit used in a rectifier has a load resistance of $200 \Omega$ and a capacitance of $15 \mu\text{F}$. The value of the time constant is . . . . . . .

Assertion : $A$ capacitor blocks direct current in the steady state.
Reason : The capacitive reactance of the capacitor is inversely proportional to frequency $f$ of the source of $emf$.

The charge on the capacitor of capacitance $C$ shown in the figure below will be

$A$ $2\ \mu F$ capacitor and an $R$ resistor are connected in series to a $200\ V$ $DC$ supply. $A$ neon bulb is connected across the capacitor,which glows at $120\ V$. Calculate the value of $R$ so that the bulb glows for $5\ s$ after the switch is closed. (Given: $\log_{10} 2.5 = 0.4$)

In the circuit shown in the diagram,the capacitances of the capacitors $C_1$,$C_2$,and $C_3$ are $4\ \mu F$,$6\ \mu F$,and $12\ \mu F$ respectively. The switch $S$ remains closed for a long time. When the switch $S$ is opened,which of the following statements will be correct about the current flowing through the battery $B$?