Power factor :
It is the cosine of the angle between the applied voltage and the resultant current flowing in circuit. Power factor is normally called lagging when current lair the applied voltage and leading when current leads the voltage. The maximum value of power factor is 1.
Power factor =active power / apparant power =watt/VA=VI cos@ =cos@
Importance of P.F :
The P.F of an current, and applied voltage are brought as near in power is possible . Low power factor possesses the following drawbacks:

  1. The current needed to obtained a given power is very high. This in turn results in the increased resistive losses, thereby resulting in decreased efficiency.
  2. It cause a poor voltage regulation.
  3. It limits the output of generators and transformer since higher current spawn out from there results in the increase in temperature.
  4. It causes fall in terminals
  5. It cause fall in terminals voltage.
  6. It causes more power loss in the line and theirby seething line efficiency.
  7. It reduces fall in terminals voaltage