You need an inductor that will store $20 \mathrm {~J}$ of energy when a $3.0$-A current flows through it. What should be its self-inductance?
A) $90 \mathrm { H }$
B) $60 \mathrm { H }$
C) $4.4 \mathrm { H }$
D) $3.7 \mathrm { H }$

Question

Quizplus · Accepted Answer

The energy stored in an inductor is given by the formula $E = \frac{1}{2} L I^2$, where $E$ is the energy in joules, $L$ is the inductance in henries, and $I$ is the current in amperes. Rearranging the formula to solve for $L$, we get $L = \frac{2E}{I^2}$. Substituting $E = 20 \, \mathrm{J}$ and $I = 3.0 \, \mathrm{A}$, we get $L = \frac{2 \times 20}{3.0^2} = \frac{40}{9} \approx 4.4 \, \mathrm{H}$.

You Need an Inductor That Will Store 20 J20 \mathrm {~J}20 J Of Energy When A

You Need an Inductor That Will Store $20 \mathrm {~J}$ Of Energy When A