Question

The three impedances Z1 = 20∠30⁰Ω, Z2 = 40∠60⁰Ω, Z3 = 10∠-90⁰Ω are delta-connected to a 400V, 3 – Ø system. Determine the phase current IR. (a) (17.32-j10) A (b) (-17.32-j10) A (c) (17.32+j10) A (d) (-17.32+j10) A This question was addressed to me during an online exam. This intriguing question comes from Three-Phase Unbalanced Circuits in division Polyphase Circuits of Network Theory Select the correct answer from above options network theory questions and answers, network theory questions pdf, network theory question bank, network theory gate questions and answers pdf, mcq on network theory pdf, gate network theory questions and solutions, network theory mcq Test , ies network theory questions, Network theory Questions for GATE EC Exam, Network Theory MCQ (Multiple Choice Questions)

Answer 1

The correct answer is (a) (17.32-j10) A Explanation: Taking VRY = V∠0⁰ as a reference phasor, and assuming RYB phase sequence, we have VRY = 400∠0⁰V Z1 = 20∠30⁰Ω = (17.32+j10)Ω IR = (400∠0^o)/(20∠30^o) = (17.32-j10) A.