A 50.0 H inductor and a 12.5 ohm resistor are connected in a series. A power source of constant 22.5 volts is applied across the series RL circuit elements at time t=0. What is the current in the circuit 10.0 seconds after the power is applied?
The time constant of the circuit is simply T = L/R = 50/12.5 = 4 second.
In RL (resistive & inductive) circuits, time constant is the time in seconds required for current to build up ...
This provides a calculation of a current in a circuit with an explanation of the steps.