Question

A (350 A/7A), 50 Hz current transformer has a primary bar. The secondary has a pure resistance of 1 Ω. It also draws a current of 5 A. The magnetic core requires 350 AT for magnetization. Find the percentage ratio error. (a) 10.56 (b) -28.57 (c) 11.80 (d) -11.80 This question was posed to me by my school teacher while I was bunking the class. Asked question is from Advanced Problems on Magnetically Coupled Circuits topic 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 answer is (b) -28.57 To explain I would say: Im = 350/1 =350 A Ip = ((nI_s^2)^2 + (I_m^2)^2)^{0.5} = 490.05 Or, n = \frac{350}{7} = 50 ∴ R = \frac{I_P}{I_S} = \frac{490.05}{7} = 70 ∴ Percentage ratio error = \frac{50-70}{70} × 100 = -28.57%.