A coil of inductance 5 H and resistance 20 Ω is connected to a DC voltage source of 100 V. Some time after a steady current exists, the voltage source is short-circuited. What will the current be (a)...

A coil of inductance 5 H and resistance 20 Ω is connected to a DC voltage source of 100 V. Some time after a steady current exists, the voltage source is short-circuited. What will the current be (a) at the time the short-circuit occurs, (b) 1 s later?