Hi! I'd like to know if there is some way of computing or deriving the energy stored in a metallic object subject to a magnetic field from external sources? Say, an iron cylinder or a sphere in a magnetic field (that is uniform or non-uniform). What is the energy in the cylinder because of this external magnetic field? Is there some formula that I can use or some concept or site that I can look at to understand this? Been stuck with this for a while and my results don't look right. Appreciate any help in advance.