A coil of inductance 0.04H and resistance 10Ω is linked to a 120V, d.c. supply. Determine
(a) The ?nal value of current,
(b) The time constant of the circuit,
(c) The value of current after a time equal to the time constant from the instant the supply voltage is connected,
(d) The expected time for the current to rise to within 1% of its ?nal value.