I would like to ask some questions on magnetic field.
1) Why there is no magnetic potential and magnetic potential energy associated
with magnetic field? Or is there?
2) It is clear that magnetic field cannot do work on a moving charged particle.
But in case of a bar magnet magnetic field seems to do work: it can attract a
piece of iron and displace it. What energy transformation is associated with
this? What changes, if any, take place in the bar magnet and its magnetic
field? To put it shortly: who pays the bill?
These were the questions asked by my International Baccalaureate high school
students. I could not answer them. Perhaps you can help me.
Regards,
Antti Savinainen
Physics teacher
Kuopio Lyseo High School/IB
Finland