Re: [Phys-L] charge in an increasing magnetic field

[brian whatcott <betwys1@sbcglobal.net>]

Remembering that your mileage may vary, I start by supposing that your 
posited scenario - the uniform increasing magnetic field with a 
stationary charged particle in it, is a whole 'nother animal from a 
primary and secondary coil wound on a ferrite core, where the coil is 
NOT in a uniform increasing field.    Although the mind retreats from 
Faraday's ideation of it,  the transformer has coils of wire with "lines 
of magnetic field CUTTING them" in his phrase.

Brian W

On 4/15/2015 8:14 PM, Philip Keller wrote:
> On 4/15/2015 5:05 PM, brian whatcott wrote:
> > My immediate intuition is that a charged particle which is stationary 
> > in an increasing uniform field feels no force. If it is initially 
> > moving, its locus is a spiral.
>
>
> But it you put a wire loop in the field, there is an induced current.  
> What force pushed the charge carriers along if not the force exerted 
> by the induced electric field?  Won't that induced field exert forces 
> on individual charges as well?  The field does not know whether the 
> charge is in a wire or not.
>
> > A uniform magnetic field has no center.
> I thought I learned otherwise from this list!  If the increasing 
> magnetic field has no "center" then the direction of the induced 
> electric field depends on where you put your conducting loop.  But 
> that can't be right!
>
> On the other hand, it is possible that I am misremembering an old 
> thread or that I misunderstood it the first time around.