Question

The meter constant of a single-phase, 230 V induction watt-meter is 600 rev/kW-h. The speed of the meter disc for a current of 15 A at 0.8 power factor lagging will be? (a) 30.3 rpm (b) 25.02 rpm (c) 27.6 rpm (d) 33.1 rpm I got this question in an international level competition. Asked question is from Advanced Problems on Magnetically Coupled Circuits in chapter Resonance & Magnetically Coupled Circuit 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 option is (c) 27.6 rpm The best I can explain: Meter constant = \frac{Number \,of \,revolution}{Energy} = \frac{600 × 230 × 15 × 0.8}{1000} = 1656 ∴ Speed in rpm = \frac{1656}{60} = 27.6 rpm.