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 Y phase.

(a) 1000

(b) 2000

(c) 3000

(d) 4000

The question was asked by my school principal while I was bunking the class.

My enquiry is from Three-Phase Unbalanced Circuits topic in division Polyphase Circuits of Network Theory

Answer 1

Right option is (b) 2000

The explanation is: The term power is defined as the product of square of current and the impedance. So the power in the Y phase = 10^2 x 20 = 2000W.