Question

A symmetrical star connected system has VRN = 230∠0⁰. The phase sequence is RYB. Find VYB. (a) 398.37∠-30⁰ (b) 398.37∠210⁰ (c) 398.37∠90⁰ (d) 398.37∠-90⁰ I have been asked this question in an online interview. Origin of the question is Voltage, Current and Power in a Star Connected System topic in section 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 option is (d) 398.37∠-90⁰ To elaborate: Corresponding line voltages are equal to √3 times the phase voltages and are 30⁰ ahead of the respective phase voltages. VYN = 230∠-120⁰V. VYB = √3×230∠(-120^o+30^o)V=398.37∠-90⁰V.