Question

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

(a) 12 A

(b) 15 A

(c) 25 A

(d) 19 A

This question was posed to me in class test.

My question is from AC Voltage Applied to a Series LCR Circuit in portion Alternating Current of Physics – Class 12

Answer 1

The correct option is (a) 12 A

For explanation I would say: R = \(\frac {V}{I} = \frac {6}{12}\) = 0.5 Ω.

Impedance = Z = R = 0.5 Ω,

Irms = \(\frac {E_{rms}}{Z}\)

Irms = \(\frac {6}{0.5}\)

Irms = 12 A.