Question

The line to line input voltage to the 3-phase, 50 Hz, AC circuit, is 100 V rms. Assuming that the phase sequence is RYB; the watt-meters would read?

(a) W1 = 886 W and W2 = 886 W

(b) W1 = 500 W and W2 = 500 W

(c) W1 = 0 W and W2 = 1000 W

(d) W1 = 250 W and W2 = 750 W

This question was posed to me in an internship interview.

The question is from Advanced Miscellaneous Problems on Measurement of Power in portion Measurement of Power and Related Parameters of Electrical Measurements

Answer 1

Correct option is (c) W1 = 0 W and W2 = 1000 W

To explain I would say: W1 = 100 × 20 cos 90° = 0

W2 = \(\frac{100 × 20 × \sqrt{3}}{\sqrt{3}  × 2}\) = 1000 W.