Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: indiced emf ....



On Thu, 19 Jun 1997, LUDWIK KOWALSKI wrote:

I agree with Nick that the situation can be turned into a paradox. One
person, "she", observes no emf accross the rod while the other, "he", does
observe it. He (the observer for whom v is not zero) strongly believes
that + and - charges are separated. He concludes that the VOLUME DENSITY
of free electrons is excessive at one end and deficient at the other. But
she (the observer sitting on the rod) does not detect any emf. Thus she
concludes that the volume densities of free electrons are identical at
two ends. ...

Both observers agree that there are surface charge accumulations. The
"moving" observer understands this to be a simple result of the action of
the background electric field while the "stationary" observer may prefer
to invoke "motional emf's" both to explain the charge separation and the
resulting (uniform) electric field inside the conductor. If there are
corona discharges both will see them and understand them in terms of the
large observed electric fields emanating from the ends of the rod. Neither
observer will see volume charge accumulations since they would produce
divergences in the internal field.

John
-----------------------------------------------------------------
A. John Mallinckrodt http://www.intranet.csupomona.edu/~ajm
Professor of Physics mailto:ajmallinckro@csupomona.edu
Physics Department voice:909-869-4054
Cal Poly Pomona fax:909-869-5090
Pomona, CA 91768-4031 office:Building 8, Room 223