Question

What is self inductance of a coil when a charge of current from 0 to 2 A in 0.05 second induces an emf of 40V in it?

• A. 1H
• B. 2H
• C. 3H
• D. 4H

Answer 1

The correct option is D 4H

We know Induced emf $e=-L\frac{dl}{dt}$

$\therefore L=-\frac{e}{\frac{dl}{dt}}=-\frac{40}{\frac{2}{0.05}}=1H$