Question

The emf in a milli henry inductor in which the current changes from 3A to 1A in a millisecond is:  
A) 2 volt        
B) 0.2 volt
C) 20 volt
D) 0.02 volt

Answer 1

V=-LdI/dt
L=1mH, dI/dt = (1-3)/.001 = -2000 A/s
V=1mH*2000A/s
= 2V