Question

The magnetic potential energy stored in a certain inductor is 15 mJ, when the current in the inductor is 40 mA. This inductor is of inductance ____________.

Options

• 0.138 H

• 18.75 H

• 1.875 H

• 13.89 H

Answer 1

The magnetic potential energy stored in a certain inductor is 15 mJ, when the current in the inductor is 40 mA. This inductor is of inductance 18.75 H.

Explanation:

`"Energy stored in inductor,"  "E" = 1/2"LI"^2`

`therefore "L" = (2"E")/"I"^2`

`= (2 xx 15 xx 10^-3)/((40 xx 10^-3)^2`

`= 18.75  "H"`