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Re: non-potential voltage



At 20:38 4/14/00 -0400, Ludwik Kowalski wrote:
I hope I am not alone who appreciates Michael's effort to bring
John's formulation closer to those who do not manipulate "divs
and rots" routinely.

I found it greatly helpful too.

A changing current induced in the circuit of the secondary
windings of a transformer can not be distinguished from the
ac part of a current produced by a battery (for example by
modulating the value of R). Amperes seem to be more real
(less dependent on interpretations) than volts.

Ludwik Kowalski

Although this mind experiment does not lend itself to an illustration
of my proposition, I assert that an electric field due to electromagnetic
induction subsists if there is conduction current or not.

Michael Edmiston wrote:
...
(3) In electrodynamics, electric field lines created by changing magnetic
fields form loops... no beginning, no ending.

I assert that a horizontal wire of 10 cm length moved horizontally,
normal to its long axis in a vertical uniform magnetic filed experiences
a lengthwise electric field which does not curl.

(5) Therefore, the work-energy situation involved in moving or allowing
charge to move in a loop of magnetically induced electric field involves
work and/or energy changes even though the charge began and ended at the
same position. This is inconsistent with our position-based definition of
electric potential difference.

It's amazing to me that even though I basically have known and taught
points
(1) through (4) for a considerable number of years, this current list
discussion has only now brought point (5) to my attention....

Michael D. Edmiston, Ph.D.


I do not find it particularly surprising that if I lift a vase of flowers
down to the floor, then set it back on the table, I have expended energy,
despite the fact the vase retains its value of potential energy, plus or
minus a petal. Am I being obtuse?
brian whatcott <inet@intellisys.net>
Altus OK