Question

The magnetic potential energy stored in a certain inductor is $25 \,mJ,$ when the current in the inductor is $60\, mA$ This inductor is of inductance

• A. 13.89 H
• B. 0.138 H
• C. 1.389 H
• D. 138.88 H

Answer 1

Answer: (A)

Energy stored in inductor
$U = \frac{1}{2}\, LI^2$
$25 \times 10^{-3} = \frac{1}{2} \times L \times (60 \times 10^{-3})^2$
$L = \frac{25 \times 2 \times 10^6 \times 10^{-3}}{3600}$
$ = \frac{500}{36}$
$ = 13.89 \, H $