Power factor

Definition

Power factor is the ratio of real power used by a circuit to the apparent power flowing into the circuit. It indicates how effectively electrical power is being converted into useful work output.

5 Must Know Facts For Your Next Test

1. Power factor ranges from 0 to 1, where 1 indicates all the power is being effectively converted into useful work.
2. A low power factor implies poor efficiency and results in higher energy losses.
3. It can be improved using capacitors or inductors to counteract the effects of inductive or capacitive loads.
4. In AC circuits, power factor is often calculated as $\cos(\phi)$, where $\phi$ is the phase difference between voltage and current.
5. Industrial applications often strive for a high power factor to reduce energy costs and improve system stability.

Review Questions

• What does a power factor of 1 indicate about an electrical circuit?
• How can you improve the power factor in an AC circuit with an inductive load?
• Why is maintaining a high power factor important in industrial applications?

Related terms

Real Power: The actual amount of power consumed by a circuit to perform useful work, measured in watts (W).

Apparent Power:

The product of the RMS values of voltage and current in a circuit, measured in volt-amperes (VA).

Reactive Power:

The portion of electricity that establishes and sustains electric and magnetic fields in an AC circuit, measured in reactive volt-amperes (VAR).