Re: [Phys-L] standard dc circuits

[brian whatcott <betwys1@sbcglobal.net>]

On 11/22/2013 6:43 PM, John Denker wrote in part:
> /snip/
> I still say that for 99% of electrical engineering and 99.99%
> of life in general, the macroscopic lumped-circuit approach
> works just fine, and worrying about the microscopic charges
> and fields is not a good use of time and effort.  It is fine
> to discuss it amongst ourselves, but I'm not at all convinced
> we should inflict it on students in the introductory course.
As usual, there is a "But..."
There is a conspicuous use for the electric field concept which appears 
to have been   relatively neglected in introductory physics. The lack of 
this concept produced many marginal signal connections in early 
computers. A simple dynamic model of potential change operating at a 
local speed of light is helpful, along with the idea of a reflected 
field at a mismatched impedance junction. When signal paths began to 
issue from sources matching a line impedance which matched the terminal 
impedance, numerous hard to understand glitches just went away....

Brian Whatcott    Altus OK