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Re: B vs H/ Transformer analogies of Poynting Vector.
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- Subject: Re: B vs H/ Transformer analogies of Poynting Vector.
- From: "Tesla list" <tesla@xxxxxxxxxx>
- Date: Tue, 26 Apr 2005 09:33:13 -0600
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Original poster: "Gerald Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
All of the engineering books that I have has always used the terms of B
being the magnetic flux density (webers/m^2 and sometimes called the tesla
:o)) ) and H being the magnetic field intensity (amps/meter). These units
are in the MKS system. CGS use strange (I guess I think MKS) units like
maxwells, guass, oersteds, etc). B=uH. Phi(webers)=BA. Mu (u) has units
of henery/meter and inductance (henery) is webers/amp. Fun to play with
unit analysis. Hope I got all the pieces for you to prove this is a self
Original poster: Harvey Norris <harvich@xxxxxxxxx>
Thought the eggheads would like this one. Sorry my
physics is fuzzy, and I shouldnt care but do...
However the debate goes on, these authors state;
"leakage flux is a essential aspect of the ideal
They have to rationalize how a transformer can work
without flux lines crossing the cores...
When I went to school B and H were strictly defined
when talking about effects. B is defined as a cross
section of amp/turns per area of cross section: H was
the magnetic intensity per unit length of core...
Around the early 80's I also attended Akron State Univ
after dropping out, but the different text from that
same Elementary Classical Physics course does not seem
to deal with H at all, as the other text did. In the
early 90's I purchased another Physics text,(Physics
for Scientists and Engineers) in which the following
is noted on pg 654;
We have named B the magnetic field and H the magnetic
intensity. These names are not universal. Sometimes B
is called the magnetic flux density and H is called
the magnetic field. Admittedly, the terminology is
confusing, and universal adoption of a single set of
terminology is unlikely in the near future.
Fortunately, the usage of the symbols B and H as we
have defined them is nearly universal. Thus the
calculation of a magnetic force on a moving charge or
a current nearly always involves B; similarly H is the
appropriate field in Ampere's Law.
Of course the above authours deal with H, and never
mention B, so I see every explanation can be made
according to the authours viewpoint. according to how
they wish to explain effects...