Re: [Phys-l] induced electric field

[Brian Whatcott <betwys1@sbcglobal.net>]

I wonder if Bob and Phillip are now reconciled to the beautifully drawn 
plots from Bob for the field conditions specified by David?

Brian W

LaMontagne, Bob wrote:
> /snip/
> I have not assumed that the E field is tangential to the loop. I am only assuming that because no boundaries are stated that no matter where I put the loop the integral (EMF) must be the same because nothing distinguishes one postion of the loop from another./snip/
>
> If a boundary is specified then the symmetry is broken and I agree with you and JD that the field at any point can be easily argued to be unique and can probably be found by some clever argument.
>
> Bob at PC
>   

> ________________________________________
> From: Philip Keller [PKeller@holmdelschools.org
>   
> /snip/ suppose you cannot assume that the field has the same magnitude at all points on the loop -- say because it is that second loop you and I were both thinking of, near but not touching the first.  At the point where the second loop is nearest the first, the electric field is pointing "the wrong way" - not in the direction of the current. /snip/the problem shows up regularly on the EM section of the AP physics C test but I don't recall symmetry or boundary conditions ever being mentioned.
>