Question

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

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

Answer 1

The correct option is D $13.89H$

Energy stored in inductor
$U=\frac{1}{2}L{I}^{2}25\times {10}^{-3}=\frac{1}{2}\times L\times {\left(60\times {10}^{-3}\right)}^2\Rightarrow L=\frac{25\times {10}^{-3}\times 2}{{\left(60\times {10}^{-3}\right)}^2}=\frac{50\times {10}^3}{3600}=\frac{500}{36}=13.89H$