Question

Find out the net power consumed over a full cycle, if a 150 Ω resistor is connected to a 350 V, 100 Hz ac supply.

(a) 2.3 W

(b) 350 W

(c) 805 W

(d) 500 W

This question was addressed to me at a job interview.

My question is from AC Voltage Applied to a Resistor topic in section Alternating Current of Physics – Class 12

Answer 1

Correct answer is (c) 805 W

For explanation: Irms = \(\frac {E_{rms}}{R}\).

Irms = \(\frac {350}{150}\)

Irms = 2.3 A.

Pav = Erms Irms

Pav = 350 × 2.3

Pav = 805 W