An inductor coil joined to a `6 V` battery draws a steady current of `12 A`. This coil is connected to a capacitor and an `AC` source of rms voltage `6 V` in series. If the current in the circuit is in phase with the emf, find the rms current.

Explanation

The resistance of the coil is ` R = *6 V)/(12 A) = 0.5 Omega`.
In the `AC` circuit, the current is in phase with the emf. This means that the net reactance of the circuit is zero. The impedance is equal to the resistance, i.e., `Z = 0.5 Omega`.
The rms current `= (rms voltage)/Z = (6 V)/(0.5 Omega) = 12 A`.