Re: [OT] VA=W?

["Paul Robinson" <ukcueman@xxxxxxx>]

> Watt are the unit for power, and is defined as U*I for DC and AC with
a
> resistive load.  However if the load are non resistive, inductive (as
in a
> electric motor) or capacitive (I can't really think of a capacitive
load..)
> the current will be out of phase with the voltage.  There are two ways
of
> dealing with this when it comes to calculating power, one is to use
the
> formula P=U*I * Cosine (of the difference in phase) you will have a
really
> correct answer and you will pass your EE exams.  In practice (and for
low
> power applications) you just say P=U*I and forget the phase question
all
> together, but use the unit VA to indicate that this is a simplified
result.
>                                         Anders

That explains the cosine things I've also seen.

Thanks!
Paul