- #1
LayMuon
- 149
- 1
The total energy of the magnetic field in the matter is [itex] \frac{\mu H^2}{2} [/itex], I want to calculated the energy that is being spent as a the work on magnetizing the material, so I need to subtract the energy of the magnetic field itself [itex] \frac{B^2}{2} [/itex] and the dipolar interaction [itex] -\vec{M} \cdot \vec{B} [/itex], however here is the problem $$ \frac{\mu H^2}{2} - \frac{B^2}{2} = \frac{\mu H^2}{2} - \frac{(\mu H)^2}{2} < 0 $$ for [itex] \mu > > 1 [/itex].
Why the energy of magnetic field itself is given by [itex] \frac{ H^2}{2} [/itex] and not by [itex] \frac{ B^2}{2} [/itex]?
Why the energy of magnetic field itself is given by [itex] \frac{ H^2}{2} [/itex] and not by [itex] \frac{ B^2}{2} [/itex]?