ALTERNATING-CURRENT CIRCUITS — Edward Purcell & David Morin
Physics — E&M · rl-circuit-transient
Problem
RL circuit ** A coil with resistance of 0.01 ohm and self-inductance 0.50 millihenry is connected across a large 12 volt battery of negligible internal resistance. How long after the switch is closed will the current reach 90 percent of its final value? At that time, how much energy, in joules, is stored in the magnetic field? How much energy has been withdrawn from the battery up to that time?