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: induced emf again



Bob Sciamanda wrote:

Ludwik asked: . . .
But Faynman argues that two ways of
changing the flux result in two different phenomena.
Right or wrong? I wish I could refer to an experimental
verification of this theoretical claim.

It may help to compare the cyclotron vs. the betatron:

The cyclotron employs only the qVxB effect to force an injected charged
particle into a circular "current". The B field is static in time. The
orbit is governed by |qVxB| = mV^2/R . There are no conductors to
constrain the motion, so that no static charges accumulate. The magnetic
field does no work - the energy of the "current" is still what it had at
injection.

Yes, the magnetic field does no work but the energy of each particle
(and thus the energy of the current) increases according to the a.c.
voltage amplitude between the Ds. I am sure Bob knows this. Another
detail is that the entire acceleration process in the betatron occurs
during a fraction of one a.c. cycle while in a cyclotron the process
takes many cycles, for example, 1000 or so.
Ludwik Kowalski