On Jun 25, 8:24*am, Cecil Moore wrote:
On Jun 24, 8:58*pm, Keith Dysart wrote:

Still does not explain why you choose only the positive root.

Of course it does. In the power density equation, choosing the
negative root would lead to a violation of the conservation of energy
principle. When one of the roots is obviously impossible in reality, a
rational person chooses the other root.

You might study why the real power folk prefer three phase to single.
It all has to do with instantaneous power.

I am a "real power folk", Keith. My first EE degree was in power
generation and transmission. Three-phase puts less stress on the
system by eliminating the hills and valleys in the energy flow common
with traveling waves.

That's the time domain. Variation in the instantaneous energy flow.

Not quite
'as useless as tits on a boar hog, or as Hecht said, putting it
mildly: "of limited utility"'.

....Keith