Question

The three impedances Z1 = 20∠30⁰Ω, Z2 = 40∠60⁰Ω, Z3 = 10∠-90⁰Ω are delta-connected to a 400V, 3 – Ø system. Find the phase current IB. (a) (34.64-j20) A (b) (34.64+j20) A (c) (-34.64+j20) A (d) (-34.64-j20) A The question was posed to me in an online interview. My enquiry is from Three-Phase Unbalanced Circuits topic 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

Correct answer is (d) (-34.64-j20) A Explanation: The voltage VBR is VBR = 400∠-240⁰V. The impedance Z3 is Z3 = 10∠-90⁰Ω => IB = (400∠240^o)/(10∠-90^o)=(-34.64-j20)A.