Question

A coil of inductance 10 H, resistance 40 Ω is connected as shown in figure. The switch S connected with point 1 for a very long time, is moved to point 2 at t=0. For the value of R obtained, the time taken for 95 % of the stored energy dissipated is ________ (a) 0.10 s (b) 0.15 s (c) 0.50 s (d) 1.0 s This question was addressed to me in an interview. The question is from Calculation of I(0+), di/dt(0+), d2I/dt2(0+) in Circuits Involving both Capacitor and Inductor topic in chapter Application of the Laplace Transform in Circuit Analysis 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 option is (c) 0.50 s For explanation: For source free circuit, I (t) = Ioe^{-\frac{R}{T} t} ∴ I (t) = 0.05 = 2 × e^{-\frac{60}{10} t} Or, t = 0.61 ≈ 0.5 s.