Worksheet: Circuits with Resistors and Inductors in Series

Practice calculating the variation with time of the current through and voltage across components in circuits that contain resistors and inductors in series. Calculate the inductive time constant of such a circuit.

Q1:

How long after switch is thrown does it take the current in the circuit shown to reach half its maximum value? Express your answer in terms of the time constant of the circuit.

Q2:

The current in the RL circuit shown below reaches half its maximum value in 1.75 ms after the switch is thrown.

Determine the time constant of the circuit if .

Determine the resistance of the circuit if .

Q3:

The switch of the circuit shown is closed at .

Determine the initial current through the battery.

Determine the steady-state current through the battery.

Q4:

For the circuit shown, emf V, inductance , and resistance Ω. Steady state is reached with closed and open. is then closed and immediately afterwards (at ) is opened.

Determine the current through at .

Determine the voltage across at .