Correct Answer - Option 3 : 1000 V
Concept:
Emf induced in a coil or inductor is given by
\(e = L{di\over dt}\)
Where,
L = Inductance
di = final value of current - initial value of current
dt = final time - initial time
Calculation:
L = 0.5 H,
di = 1 - (-1) = 2 A
dt = 1 msec
\(e = (0.5){(2)\over (0.001)}\)
e = 1000 V
