Question

In the measurement of 3-phase power by 2 watt-meter method, if the 2 watt-meter readings are equal, the power factor of the circuit is?

(a) 0.8 lagging

(b) 0.8 leading

(c) Zero

(d) Unity

The question was posed to me in an internship interview.

I'm obligated to ask this question of Advanced Problems on Measurement of Power in Polyphase Circuit in portion Measurement of Power and Related Parameters of Electrical Measurements

Answer 1

Right answer is (d) Unity

Best explanation: Power factor, cosθ = cos arc tan (3)^0.5 \(\frac{W_1-W_2}{W_1+W_2}\)

W1 = W2 = cos 0° = 1.