sci.physics.electromag

On Nov 24, 1:53 pm, "Green Xenon [Radium]"
> "Magnetic effective resistance is the parameter of a passive magnetic
> circuit or its element, which is equal to the relation of the effective
> power, which is absorbing in this element, to the square of the
> effective value of a magnetic current in it."
>
> Magnetic current???? You mean to tell me such a paradisical and magical
> entity exists????
No, the term "magnetic current" is not being applied to magnetic
monopoles in those references. It is referring to electric charges
moving in a circular pattern or some approximation of it. The term
"electric current" is being applied to electric charges moving in a
straight line pattern or some approximation of it.
Note that even in this definition, a "magnetic field" is not a
"magnetic current." The analogy of some objects with nonzero rest mass
moving from the south pole to the north pole is still not valid.
I know that I said earlier that magnetic current refers to the
motion of monopoles and I am sorry. I apologize. However, the way your
question was asked logically implies the existence of isolated
magnetic monopoles. The magnetic field is not a magnetic current.
Nor at present has anyone isolated a magnetic monopole. The
mathematics implies that a small loop of circulating electric current
can be replaced by an equivalent magnetic dipole, which can be
pictured in approximation as two magnetic monopoles of opposite
polarity very close together. However, this is an APPROXIMATION. The
two monopoles do not really exist. If one were to try and separate
these make believe magnetic monopoles, one could get a shock from
electric charge. The flow of these make believe "magnetic monopoles"
would be a magnetic current. Somehow, these engineers have decided to
place this APPROXIMATION in the definition.
Sheesh, engineers. Placing an approximation in a definition. I am
so glad I am a physicist. I would never refer to a circulating
electric current as a magnetic current. I promise you that in my
physics classes I will warn the students the coming approximations
before I use the words "magnetic current."


I didn't know this before you asked the question, so thanks. I
did look further at the same Wikepedia references.
I got this by searching for the term "magnetic current" in the
"Magnetic Field" entry on Wikepedia
(1) Magnetic induction current causes a magnetic current density

\mathbf{B} =3D \mu \mathbf{H}

was essentially a rotational analogy to the linear electric current
relationship,

(2) Electric convection current

\mathbf{J} =3D \rho \mathbf{v}

where =CF=81 is electric charge density. \mathbf{B} was seen as a kind of
magnetic current of vortices aligned in their axial planes, with
\mathbf{H} being the circumferential velocity of the vortices. With =C2=B5
representing vortex density, we can now see how the product of =C2=B5 with
vorticity \mathbf{H} leads to the term magnetic flux density which we
denote as \mathbf{B}.

The electric current equation can be viewed as a convective current of
electric charge that involves linear motion. By analogy, the magnetic
equation is an inductive current involving spin. There is no linear
motion in the inductive current along the direction of the \mathbf{B}
vector. The magnetic inductive current represents lines of force. In
particular, it represents lines of inverse square law force.