An inductance L and a resistance R are connected in series to an ideal battery. A switch in the circuit is closed at time 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 is increasing most rapidly, which occurs at t = (L/R)ln 2.

An Inductance L and a Resistance R Are Connected in Series