Question

Find out the rms value of current in the circuit wherein a 35 mH inductor is connected to 200 V, 70 Hz ac supply.

(a) 13 A

(b) 15 A

(c) 20 A

(d) 45 A

The question was asked in a job interview.

Enquiry is from AC Voltage Applied to an Inductor in division Alternating Current of Physics – Class 12

Answer 1

The correct option is (a) 13 A

The explanation is: XL = 2π f L

XL = 2π × 70 × 35 × 10^-3 Ω.

Irms = \(\frac {E_{rms}}{X_L} = \frac {200}{(2\pi \times 70 \times 35 \times 10^{-3})}\)

Irms = 12.99 A ≈ 13 A

Therefore, the rms value of current in the circuit is 13 A.