Determine the energy associated with the magnetic field of a 200-turn solenoid in which a current of 1.75 A produces a flux of 3.7 x 104 Wb in each turn.
The self-induced emf in a .2-H coil when the current in it is changing at the rate of 200 A/S is
(a) 20V
(b) 40V
(c) 100V
(d) 400V