David Combs wrote:

With DC, the pf is 1.0?

Yes.

With AC, I'm not sure what it is.

With AC, it's the sum of instantaneous products of current and voltage
over a cycle, divided by the product of their average values.
It's 1.0 if current is proportional to voltage.

It's also the number you see when you push the PF button on a Kill-a-Watt
meter. I did that with a "0.1A 120V" Little Giant fountain pump the size
of a golfball and saw 0.42. The meter said the pump used 5 watts.

Nick