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#### electronicsman

##### Full Member level 5
The power per phase is defined as where i don't understand the term Theta. I know the phase angle between the
voltage and current if there is reactance they are not in phase .
What does the below statement mean?

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##### Super Moderator
Staff member
Does this have to do with power factor error? Due to reactance effects, voltage waveform does not coincide with Ampere waveform.

Impedance waveform does not coincide with either of the two. Evidently the author sees the three waveforms are all out of phase. So he clarifies his expression.

Theta often designates angle. In this case it's the amount by which sine (or cosine) waveforms are out of phase.

#### electronicsman

##### Full Member level 5
So for example the voltage and current are out of phase by 30Degrees. and the voltage leads the current by 30. From calculations the impedance leads by 30 Degrees. The author is referring to the +30 Degrees of impedance wrt voltage phase?

#### FvM

##### Super Moderator
Staff member
I don't give a damn for unknown citations...
For a serious discussion, give the source and context.

For me, the quoted statement doesn't make sense. You know that Z=V/I, each being a complex quantity. Respectively the angle of Z is the angle between V and I. If V is leading I by 30 degree (inductive load), Z has an angle of +30 degree.

#### KlausST

##### Super Moderator
Staff member
Hi,

when I first read the post my idea was exactly like FvM´s.
Without context the statement makes no sense. .. and it makes any further discussion almost useless guessing.

Klaus