An inductance L and a resistance R are connected in series to an ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.The rate of increase of the energy stored in the inductor is a maximum:
A)just after the switch is closed
B)at the time t = L/R after the switch is closed
C)at the time t = 2L/R after the switch is closed
D)at the time t = (L/R)ln 2 after the switch is closed
E)a long time after the switch is closed

Question

Quizplus · Accepted Answer

The rate of increase of energy stored in the inductor is maximum when the current through the inductor is increasing most rapidly, which occurs at the time $t = \frac{L}{R}\ln 2$, according to the time constant of an RL circuit.

An Inductance L and a Resistance R Are Connected in Series