After a switch is thrown to remove the battery from a DC LR circuit, but the circuit is still left complete, the time constant represents
A) the time rate of change of the current in the circuit.
B) the time rate of change of the induced emf in the circuit.
C) the magnitude of the ratio of the current to the time rate of change of the current.
D) all of the above.
E) only (a) and (b) above.

Question

Quizplus · Accepted Answer

The time constant in an LR circuit represents the magnitude of the ratio of the current to the time rate of change of the current. It is a measure of how quickly the current will decay to zero after the battery is removed, not directly related to the time rate of change of the current or induced emf itself.

After a Switch Is Thrown to Remove the Battery from a DC