Talking about magnetic field, we have three relevant physical quantities - magnetic field \(\vec{H}\), magnetic induction field \(\vec{B}\) and magnetization field \(\vec{M}\). It is straightforward to understand \(\vec{M}\) - when applying magnetic field (here, by 'magnetic field', we mean something in general, but not specifically refer to \(\vec{H}\)), we use \(\vec{M}\) to characterize how much the matter in question is magnetized. However, concerning \(\vec{H}\) and \(\vec{B}\), it seems that both are describing some sort of 'strength' of magnetic field (again, we mean 'magnetic field' in general. The same applies below until we become specific about what we mean by 'magnetic field'). But why do we have two quantities here to describe the 'same' thing? The answer is - they are not the same thing, as described by \(\vec{H}\) and \(\vec{B}\), respectively. Fundamentally, this goes back to the foundation of the electromagnetic theory - specific
Personal blog recording my learning notes for various topics.