Often a terminology is used in Electrodynamics

[saravanan13]

Often a terminology is used in Electrodynamics "in the absence of static and moving charges" of a magnetic medium. what does this corresponds to and how do Maxwell turns out to be in this situation?
Please explain the context in detail.

 

[cragar]

They might be referring to the relative permeability of the material.
$$B=\mu(H)$$
Not completely sure tho.

 

[chrisbaird]

In reality, you can't have magnetic effects without electric charges. What they mean is there are no excess charges or currents . Excess charges would lead to electrostatic effects and excess currents would lead to extra magnetic fields. It sounds like the textbook is trying to isolate magnetostatic material effects for comprehension purposes from electrostatic effects and current-magnetic effects. A permanent magnet with nothing additional done to it could be thought of as a magnetic material with no excess charges or currents. Sure, there are electrons zipping about inside the magnet. But on the macroscopic level, the electrons' charge is canceled by the charge of the nuclei, so there is no net charge. And for similar reasons, there is no net excess current flowing through a permanent magnet left to itself.