The inductive reactance of a coil is $R$. If the inductance of the coil is doubled and the frequency of the $A.C.$ supply is also doubled,then the new inductive reactance will be:

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

In a purely resistive $ac$ circuit,the current

Keeping the source frequency equal to the resonating frequency of the series $LCR$ circuit,if the three elements,$L, C$ and $R$ are arranged in parallel,show that the total current in the parallel $LCR$ circuit is minimum at this frequency. Obtain the $rms$ current value in each branch of the circuit given below.
Figure shows a series $LCR$ circuit connected to a variable frequency $230\; V$ source. $L=5.0\; H, C=80\; \mu F, R=40\; \Omega$.

Inductive reactance . . . . . .

$A$ resistor of resistance $100 \Omega$ is connected to an $AC$ source $\varepsilon = 10 \sin (250 \pi t)$. The energy dissipated as heat during $t = 0$ to $t = 1 \text{ ms}$ is approximately.