I have had this question since I was in college physics, but never could figure out how to express it. Well, now I think I have it.
Let's imagine two scenarios A and B. Both scenarios start with two non-magnetized iron bars. In scenario A, the iron bars are 0.1 m apart. In scenario B, they are 0.5 m apart. In both scenarios, one bar is magnetized over time to the same strength.
The question is in two parts:
- do the potential energies due to magnetism differ in the two scenarios?
- does the energy required to magnetize the iron bar differ in the two scenarios?
The question relates to how to account for the difference in potential energy. My reasoning is that the only place it can be drawn from is the energy required to magnetize the bar. Is this reasoning correct?