Question

The three impedances Z1 = 20∠30⁰Ω, Z2 = 40∠60⁰Ω, Z3 = 10∠-90⁰Ω are delta-connected to a 400V, 3 – Ø system. Find the power in the B phase.

(a) 0

(b) 1

(c) 3

(d) 2

I got this question in examination.

The question is from Three-Phase Unbalanced Circuits topic in division Polyphase Circuits of Network Theory

Answer 1

Correct answer is (a) 0

Easy explanation: The term power is defined as the product of square of current and the impedance. So the power in the B phase = 40^2 x 0 = 0W.