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

[Philip Keller <pkeller@holmdelschools.org>]

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.