Why is a magnetic field of a permanent magnet not considered energy? The first law says you can’t create energy. OK, but you can give energy to a ferromagnet and magnetize it. Then you can magnetize as many other ferromagnetic materials as you want, and not diminish the magnetic field of the first one you had. I don’t understand how there can be no loss and how that is not considered breaking the first law.
 A: A magnetic field is a form of energy.  Energy is required to form a permanent magnet by, e.g., aligning the spins of electrons in a material.  That energy is stored in the resulting macroscopic magnetic field. The same is true of an electric field: energy is stored in the macroscopic electric field when positive and negative electric charges are separated, e.g., in a capacitor.
When a permanent magnet is used to magnetize another object, field energy is indeed added to the object, but the energy comes from the mechanical force applied to accomplish the magnetization. Field energy is not typically transferred from the permanent magnet to the object.
A: You cannot magnetize something without bringing it into the magnetic field but that takes work and the amount of work you have done while keeping the magnetic field unchanged is the energy acquired by the newly magnetized body. If the source of the magnetic field is a permanent magnet whose magnetization does not change while moving another magnetizable body near it, then the motional work is purely mechanical and the energy is partly potential (i.e., depends on the location in the field) and also partly magnetic because you induce a magnetic field in the body and polarize the body. This magnetic energy can be directly expressed as the mutual energy of the induced magnetic volume and surface charges.   If the source is current then you also have to work maintaining the current so it is not changing despite the other body interacting with it (Lenz law). That work is by the battery but the result is the same as in the case of the permanent magnet source: the work done is the energy acquired by the body as it is moved in the field.
