Energy stored in an inductor is given by: (Given L is inductance, I is current, N is number of turns of coil, A is area of cross section, μ is permeability of flux and Φ is flux)
1
\(\rm \frac{\mu N^2A}{L}\)
2
\(\rm L\frac{di}{dt}\)
3
\(\rm \frac{N\Phi}{I}\)
4
\(\rm \frac{1}{2}LI^2\)