The $r.m.s.$ current in an $AC$ circuit is $2 \ A$. If the wattless current is $\sqrt{3} \ A$,what is the power factor?

An alternating supply of $220\,V$ is applied across a circuit with resistance $22\,\Omega$ and impedance $44\,\Omega$. The power dissipated in the circuit is.........$W$.

An inductor $20 \, mH$,a capacitor $100 \, \mu F$ and a resistor $50 \, \Omega$ are connected in series across a source of emf,$V = 10 \sin(314 \, t)$. The power loss in the circuit is ...... $W$.

If the power factor in an $AC$ circuit changes from $\frac{1}{3}$ to $\frac{1}{9}$,then by what percent will the reactance change (approximately),if the resistance remains constant?

The power factor of the circuit shown in the figure is:

The power factor of an $ac$ circuit having resistance $(R)$ and inductance $(L)$ connected in series and an angular velocity $\omega$ is: