Three identical capacitors are given a charge $Q$ each and they are then allowed to discharge through resistances $R_1, R_2,$ and $R_3$. Their charges,as a function of time,are shown in the graph below. The smallest of the three resistances 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 $emf$.

In order to obtain a time constant of $10 \ s$ in an $RC$ circuit containing a resistance of $10^3 \ \Omega$,the capacity of a condenser should be..... $\mu F$.

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

An $RC$ circuit as shown in the figure is driven by an $AC$ source generating a square wave. The output wave pattern monitored by $CRO$ would look close to

In the circuit shown below,the key is pressed at time $t=0$. Which of the following statement$(s)$ is(are) true?
$(A)$ The voltmeter displays $-5 \ V$ as soon as the key is pressed,and displays $+5 \ V$ after a long time.
$(B)$ The voltmeter will display $0 \ V$ at time $t=\ln 2 \ s$.
$(C)$ The current in the ammeter becomes $1/e$ of the initial value after $1 \ s$.
$(D)$ The current in the ammeter becomes zero after a long time.