An inductance L, resistance R, and ideal battery of emf are wired in series.A switch in the circuit is closed at time t = 0, at which time the current is zero.At any later time t the emf of the inductor is given by: A)(1 - e^-^Lt^/^R) B)e^-^Lt^/^R C)(1 + e^-^Rt^/^L) D)e^-^Rt^/^L E)(1 - e^-^Rt^/^L)

Question

Quizplus · Accepted Answer

The emf of the inductor in an LR circuit is given by L(di/dt), where di/dt is the rate of change of current. The current in an LR circuit grows according to I(t) = (emf/R)(1 - e^(-Rt/L)), so the rate of change of current is proportional to e^(-Rt/L). Thus, the emf of the inductor is proportional to e^(-Rt/L).

An Inductance L, Resistance R, and Ideal Battery of Emf