Question

The expression for lower half power frequency is? (a) (-R+√(x^2+4LC))/4πL (b) (–R-√(x^2+4LC))/4πL (c) (R-√(x^2+4LC))/4πL (d) (R+√(x^2+4LC))/4πL I had been asked this question in an international level competition. My doubt stems from Bandwidth of an RLC Circuit 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

Correct answer is (a) (-R+√(x^2+4LC))/4πL To explain: Selectivity indicates how well a resonant circuit responds to a certain frequency and eliminates all other frequencies. At lower power frequency, XC > XL(1/2πf1C)-2πf1L=R. f1 = (-R+√(x^2+4LC))/4πL.