Question

In the figure given below, a 220 V 50 Hz supplies a 3-phase balanced source. The pressure Coil (PC) and Current Coil (CC) of a watt-meter are connected to the load as shown. The watt-meter reading is _________ (a) Zero (b) 1600 W (c) 242 W (d) 400 W The question was posed to me in an interview for internship. The above asked question is from Problems Involving Coupling Coefficient 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) 242 W Explanation: Watt-meter reading = Current through CC × Voltage across PC × cos (phase angle). IBR = ICC = \frac{220∠120°}{100°} = 2.2∠120° VYB = VPC = 220∠-120° w = 2.2∠120° × 220∠-120° × cos 240° = – 242 W.