A resistor and an inductor are connected in series to a battery. The battery is suddenly removed from the circuit. The time constant for of the circuit represents the time required for the current to decrease to
A)25% of the original value.
B)37% of the original value.
C)50% of the original value.
D)63% of the original value.
E)75% of the original value.

Question

Quizplus · Accepted Answer

The time constant in an RL circuit is the time it takes for the current to decrease to 37% (1/e) of its original value after the battery is removed.

A Resistor and an Inductor Are Connected in Series to a Battery