InterviewSolution
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InterviewSolution
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Self-inductance of a coil is 2mH, current through this coil is, `I=t^(2)e^(-t)` (t = time). After how much time will the induced emf be zero? |
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Answer» Induced emf, `E=-L(dI)/(dt)` Now, `(dI)/(dt)=(d)/(dt)(t^(2)e^-t)=2te^(-t)-t^(2)e^(-t)` `=-e^(-t).t(t-2)` Hence, `E=Le^(-t)t(t-2)` So, if E = 0, then t = 0 or 2 Therefore, after 2s from the initial moment, the induced emf will be zero. |
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