呢條問題點做，求解答?

(a) Net voltage across 1-ohm resistance = (12 - emf ), where emf is the induced emf across the coil.
Using Ohm's Law, 12 - emf = 8 x 1
emf = (12 - 8) v = 4 v

(b) 4 = L x 400, where L is the inductance of the coil
i.e. L = 0.01 H

(c) Rate of current increase = 12/0.01 A/s = 1200 A/s

(d) Steady state current = 12/1 A = 12 A

(e) Energy stored = (1/2).(0.01).(12^2) J = 0.72 J