Question

A series RLC circuit has a resonance frequency of 1 kHz and a quality factor Q = 50. If R and L are doubled and C is kept same, the new Q of the circuit is? (a) 25.52 (b) 35.35 (c) 45.45 (d) 20.02 The question was posed to me in a job interview. My doubt stems from Problems of Series Resonance Involving Frequency Response of Series Resonant Circuit topic in division 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

Right answer is (b) 35.35 Easy explanation: Quality factor Q of the series RLC circuit is given by, Q = \(\frac{1}{R} \sqrt{\frac{L}{C}}\) Qnew = \(\frac{1}{2R} \sqrt{\frac{2L}{C}} = \frac{1}{2} × \frac{1}{R} \sqrt{\frac{2L}{C}} = \frac{1}{2} × \sqrt{2} × Q\) = 35.35.