If $L$,$C$,and $R$ are the self-inductance,capacitance,and resistance respectively,which of the following does not have the dimension of time?

Answer the following questions:
$(a)$ In any $ac$ circuit, is the applied instantaneous voltage equal to the algebraic sum of the instantaneous voltages across the series elements of the circuit? Is the same true for $rms$ voltage?
$(b)$ Why is a capacitor used in the primary circuit of an induction coil?
$(c)$ An applied voltage signal consists of a superposition of a $dc$ voltage and an $ac$ voltage of high frequency. The circuit consists of an inductor and a capacitor in series. Show that the $dc$ signal will appear across $C$ and the $ac$ signal across $L$.
$(d)$ $A$ choke coil in series with a lamp is connected to a $dc$ line. The lamp is seen to shine brightly. Insertion of an iron core in the choke causes no change in the lamp's brightness. Predict the corresponding observations if the connection is to an $ac$ line.
$(e)$ Why is a choke coil needed in the use of fluorescent tubes with $ac$ mains? Why can we not use an ordinary resistor instead of the choke coil?

The vector diagram of current and voltage for a circuit is as shown. The components of the circuit will be

In domestic electric mains supply,the voltage and the current are

In an $A.C.$ circuit,the current:

An $LCR$ circuit is equivalent to a damped oscillator. $A$ capacitor is charged to a charge $Q_0$ as shown and then connected to $L$ and $R$. If a student plots graphs of the square of the maximum charge on the capacitor $(Q^2_{max})$ versus time for two different values of inductors $L_1$ and $L_2$ $(L_1 > L_2)$, which of the following graphs will correctly represent it? (The diagram is schematic and not drawn to scale.)