Question

What is the Formula of power factor?


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Answer 1

This therefore gives us: Power Factor = Real Power/Apparent Power, or p.f. = W/VA. Then the cosine of the resulting angle between the current and voltage is the power factor. Generally power factor is expressed as a percentage, for example 95%, but can also be expressed as a decimal value, for example 0.95.

Answer 2

Power factor is only and only related to AC circuits i.e. there is no power factor (P.f)  in DC circuits due to zero frequency and phase angle difference (Φ) between current and voltage.                      

The Cosine of angle between Current and Voltage is called Power Factor.

$P = VI Cos\theta$ OR

$Cos\theta = P \div V I$ OR

$Cos\theta = kW \div kVA$ OR

$Cos\theta =$True Power $\div$ Apparent Power

Where:

P = Power in Watts

V = Voltages in Volts

I = Current in Amperes

W = Real Power in Watts

VA = Apparent Power in Volt-Amperes or kVA

$Cos\theta =$Power factor

2). The ratio between Resistance and Impedance in AC Circuit is known as Power Factor.                    $Cos\theta = R \div Z$

Where:

R = Resistance in Ohms (Ω)

Z = Impedance (Resistance in AC circuits i.e. XL, XC and R known as Inductive reactance, capacitive reactance and resistance respectively) in Ohms (Ω)

$Cos\theta=$ Power factor

#SPJ2