Question

What is the magnitude of the induced E.M.F of a coil of inductance 30mH in which the current changes from 6A to 2A in 2 seconds?

Answer 1

Induced emf is given by:

$e=−L \frac { di} { dt} ​$

​$=−30×10 ^{ −3} × \frac {4}{2}$

$=0.06 V$