An a.c. source of frequency $f$ is connected to a circuit containing an inductance $L$ and resistance $R$ in series. The impedance of this circuit is

$A$ series $R-C$ circuit is connected to an alternating voltage source. Consider two situations:
$(a)$ When the capacitor is air-filled.
$(b)$ When the capacitor is mica-filled.
If the current through the resistor is $i$ and the voltage across the capacitor is $V$,then:

When $100 \, V$ $DC$ is applied across a coil,a current of $1 \, A$ flows through it. When $100 \, V$ $AC$ at $50 \, Hz$ is applied to the same coil,only $0.5 \, A$ current flows. The impedance of the coil is ....... $\Omega$.

If $A$ and $B$ are identical bulbs,which bulb glows brighter?

$A$ circuit when connected to an $A.C.$ source of $12 \; V$ gives a current of $0.2 \; A$. The same circuit when connected to a $D.C.$ source of $12 \; V$,gives a current of $0.4 \; A$. The circuit is

In the given circuit,the angular frequency of the voltage source is $70 \times 10^3 \text{ rad s}^{-1}$. The circuit effectively behaves like,