power factor definition

Question

Power factor of AC circuit equals?

RankGuru · Accepted Answer

1. **Definition**: The **Power Factor** is the ratio of true power (consumed in resistance) to apparent power (delivered by source).
2. **Geometric View**: In the impedance triangle, it is the cosine of the phase angle $\phi$ between voltage and current:
   $\cos \phi = \frac{R}{Z} = \frac{	ext{Resistance}}{	ext{Impedance}}$
3. **Ranges**: 
   - Purely resistive: $\phi = 0^\circ, \cos \phi = 1$.
   - Purely inductive/capacitive: $\phi = 90^\circ, \cos \phi = 0$ (Wattless current).

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power factor definition

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