Re: ---My wiring questions (was progress on Travelette - premature sending)

[John Hofstetter <hofs@xxxxxxxxxxxx>]

On Sunday, June 29, 2003, at 01:46  PM, Allan Ericson wrote:

> Likewise, on the rheostat, there are two leads in series with the light
> bulb. You put your meter across them. The two voltages (across the
> bulb and
> across the rheostat) add up to the total voltage in the circuit, less
> any
> losses for wire lengths or anything else you may have added into the
> circuit. The impedance of the meter is so high that it will not
> significantly affect the readings.
Hmm, interesting.

Until my son taught me to use a voltmeter in series to measure things
like the voltage between a battery terminal and the battery post, I had
never used a voltmeter in series. Im still not sure why that works,
but it works well for him in much of his vehicle testing.

He claims that his puzzling me with how this works is payback for when
I beat him around and about his head and body after he used my ammeter
in parallel.

So, is there an understandable-to-me reason for squaring the voltage
before dividing by the resistance in order to get the wattage? Never
mind, I just figured it out.  Watts = E/R *E  = E squared/R    Thanks
again.

John Hofstetter