In sci.physics.electromag, jimp@[EMAIL PROTECTED]
wrote:
> EskWIRED@[EMAIL PROTECTED]
wrote:
>
> > Ummm....using any wire of any thickness and a given resistance per
unit of
> > length, why is it that more voltage will yield more current? Is it a
> > matter of velocity of electron flow?
> Because E=IR which is basic Ohm's Law.
That I know. The question is why.
> > Why, for example, does one needs to use thicker wires on the low side
of a
> > transformer, while on the high side, one can use thinner wires?
> Because P=I^2 R and P=EI.
That I already know.
> The power in and power out of a transformer (ignoring losses) are equal,
> but the voltages aren't, which is normally why one is using a
transformer
> in the first place.
> So, for a fixed amount of power, the current is higher on the low side,
> hence thicker wire to carry that current and less loss in the winding
> due to I^2 R losses.
> On the high side, keeping in mind the power is fixed, the current is
> lower hence you don't need wire as thick as the low side.
> > I'm not asking to be told that the resistance of the thick wire is
lower,
> > so by applyng Ohm's law, we see that....
> >
> > Instead, I'm asking what is going on at a particle level. And
> Ohm's law works at the macro level and answers the questions.
> Analysis at the particle level doesn't really address the questions
> you asked.
> > additionally, as a corollary question, I'm asking whether the
associated
> > magnetic field propogates down the length of the wire at a greater
> > velocity at higher voltage.
> No.
> The magnitude of the magnetic field is a function of current.
> The magnetic field propogates at c.
I thought that electromagnetic fields propogated at C only in free space.
Doesn't a wire provide significant resistance?
Are you saying that low voltage electricity travels at the same velocity
as high voltage electicity?
--
The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts.
-- Bertrand Russel
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