What is Power Factor and what is its unit?

Power factor is a measure of how effectively electrical power is being converted into useful work output and is defined as the ratio of real power (measured in watts) to apparent power (measured in volt-amperes). This ratio quantifies the operational efficiency of an electrical system, particularly in AC circuits where both current and voltage can be out of phase.

The unit of power factor is dimensionless, often expressed as a ratio or a percentage, indicating the portion of total power that is effectively utilized to perform work. While the correct choice refers to kilowatts (kW) in the context of real power, the key aspect is recognizing that power factor is fundamentally about the relationship between real power and apparent power, rather than just the specific units involved, such as kW, VA, or other forms of power measurement.

Other options do not accurately define power factor and relate it to its unit correctly:

• While VA and watts are relevant to power measurements, they do not capture the concept of a ratio between real and apparent power.

• The mention of active power consumed again focuses on a single aspect of power but fails to convey the relationship that defines power factor.

• The term 'efficiency of power delivery' does not accurately describe power factor