Question

A three-phase balanced delta connected load of (4+j8) Ω is connected across a 400V, 3 – Ø balanced supply. Determine the phase current IB. (a) 44.74∠303.4⁰A (b) 44.74∠-303.4⁰A (c) 45.74∠303.4⁰A (d) 45.74∠-303.4⁰A This question was addressed to me in examination. Origin of the question is Three-Phase Balanced Circuits in portion 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

Right choice is (b) 44.74∠-303.4⁰A The explanation is: Taking the line voltage VRY = V∠0⁰ as a reference VRY = 400∠0⁰V, VYB = 400∠-120⁰V and VBR = 400∠-240⁰V. Impedance per phase = (4+j8) Ω = 8.94∠63.4⁰Ω. Phase current IB = (400∠240^o)/(8.94∠63.4^o) = 44.74∠-303.4⁰A.