Concepts Of Physics MCQ Edition [Volume 2]PhysicsAlternating Current
An inductor coil, a capacitor, and an AC source with an rms voltage of 24 V are connected in series. A maximum rms current of 6.0 A is observed when the frequency of the source is varied. Determine the current if this inductor coil is connected to a battery of emf 12 V and internal resistance 4.0 .
Options
- A1.5 A
- B4.5 A
- C3.0 A
- D2.0 A
Correct answer
A. 1.5 A
Step-by-step solution
In an AC circuit, the maximum rms current occurs at resonance when the inductive reactance equals the capacitive reactance. At this frequency, the impedance of the circuit is purely resistive and is equal to the resistance of the inductor coil, R . The resistance of the coil is given by: R = V_ rms I_ rms = 24 6.0 = 4.0 When the inductor coil is connected to a DC battery, it offers zero inductive reactance in the steady state. The total resistance in the circuit is the sum of the coil's resistance and the battery's