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Re: [Phys-L] uniform field?



Ack. Thanks for the correction Curtis. I believe I was thinking of solenoid and magnetic fields. I need to brush up on my E&M it appears.

Jacob Turner - (208) 885-2730
Director of Physics Laboratory Education
University of Idaho

On Jul 23, 2012, at 5:08 PM, "curtis osterhoudt" <flutzpah@yahoo.com> wrote:

Ouch. No. A standard Gaussian pillbox is perhaps the quickest way to see that an infinite-plate's field doesn't fall off, though the "field-of-view" argument is more viscerally pleasing (at least to me), and one can always do the direct integration over a uniform surface charge.


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________________________________
From: "Turner, Jacob" <turner@uidaho.edu>
To: Phys-L@Phys-L.org
Sent: Monday, July 23, 2012 3:30 PM
Subject: Re: [Phys-L] uniform field?

The field from a single plate falls off as you move from that plate. But this is directly compensated for by the field from the other plate growing by the same amount.

So net field is constant, field from a single plate is variable.

Jacob Turner - (208) 885-2730
Director of Physics Laboratory Education
University of Idaho

On Jul 23, 2012, at 4:27 PM, "Paul Lulai" <plulai@stanthony.k12.mn.us> wrote:

Hello.
I need help with a fundamental concept I thought I understood, but seem to have some trouble with.
I continually read about parallel plates with a uniform field btn the plates (assuming the distance btn plates is small in comparison to the length of the plates so one can neglect end effects). These parallel plates often have field lines drawn in which the field lines are all equally spaced. I've also seen some parallel plates with field vector arrows. The arrows are equally sized and spaced and vertical (assuming horizontal plates).
I have seen a couple of items recently that imply that the field strength varies as one moves from one plate to the other. That disagrees with my interpretation of the word 'uniform' and with my interpretation of the field line drawings and field vector arrow drawings. I thought the word uniform and the field lines (or arrows) all implied the field strength was constant as one moves from one plate to the next.
Am I missing something?

Thanks for any clarification.
Have a good one.
Paul.
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