On Mon, 31 Aug 2009 02:45:56 GMT, (Doug Miller)
wrote:

In article , Metspitzer wrote:
On Sun, 30 Aug 2009 20:58:38 GMT, (Doug Miller)
wrote:

In article
, JIMMIE
wrote:

It does not affect the current that the wire COULD carry or the
AMPacity. A long cable, compared to a short cable, will the current
in the total circuit because it adds resistance to the total circuit.

Adding resistance to a circuit changes voltage, not current.

I can't believe what I am hearing.

Oh? What's the problem?

If you add resistance in series to the destination load (which is what
higher wire resistance does), the *total* R seen by the source is
higher. Assuming a constant V at the source, this means I (current)
through the wire will be lower.

At the *load*, V will be lower also (often called the "IR drop" of the
wire) -- the load is now part of a "voltage divider".

So yes, adding resistance changes both voltage (away from the source)
and current.

Another way to think of it -- if the V across the final load (constant
R) is lower, the current (I) must also be lower. Circuit analysis can
be kind of fun -- you can often approach it from multiple perspectives
and get the same answer.

This assumes a constant resistance load, which a light bulb isn't
completely, but is sufficient for this purpose.

Josh