A friend and I had a discussion about the potential energy of a permanent magnet, and we want to find out which of our views is right, but we can't seem to find information to confirm/disprove either view. So here are our different ideas:
-Both magnetising and demagnetising a magnet costs energy, realigning the magnetic moments takes energy which is lost in a sort of 'realigning friction'. Some of the magnetic field used to magnetise is converted to heat (even when the usual losses such as eddy currents and coil resistance are ignored).
-The magnetised and unmagnetised state of a permanent magnet have different energies, it would be theoretically possible to extract some energy by realigning the magnetic moments, though the magnitude of the magnetic field necessary for this realignment obscures this small potential energy in practical situations.
Any thoughts/sources are appreciated!
