The reactance of a coil when used in the domestic $ac$ power supply $(220\, V, 50\, Hz)$ is $100\, \Omega$. The self-inductance of the coil is nearly........$H$.

The inductive reactance of a coil is $X_{L}$. If the inductance of a coil is tripled and the frequency of the $A.C.$ supply is doubled,then the new inductive reactance will be

In the graphical representation of e.m.f. $e$ and current $i$ versus $\omega t$ for an a.c. circuit,both emf and current reach zero,minimum,and maximum values at the same time. The circuit element connected to the source will be

The current flowing in a coil is $3 \text{ A}$ and the power consumed is $108 \text{ W}$. If the a.c. source is of $120 \text{ V}, 50 \text{ Hz}$,the resistance in the circuit is (in $\Omega$)

In a circuit,the current lags behind the voltage by a phase difference of $\pi / 2$. The circuit will contain which of the following?

An $A.C.$ voltage is applied to a pure inductor. The current in the inductor