The induced emf in a coil of 10 H inductance in which current varies from 9 A to 4 A in 0.2 s is

Options

(a) 200 V
(b) 250 V
(c) 300 V
(d) 350 V

Correct Answer:

250 V

Explanation:

Induced emf, e = -L (di / dt)
Given, L = 10 H, Δi = 9 – 4 = 5 A,
dt = 0.2 s
emf, e = 10 × (5 / 0.2) = 250 V