How is power factor defined in electrical terms?

Power factor is defined as the ratio of real power to apparent power in an electrical circuit. This concept is crucial in AC (alternating current) systems, where power can be categorized into real power (the actual power that performs work) and apparent power (the product of the current and voltage in a circuit).

Real power, measured in watts (W), represents the active power consumed by resistive elements to perform useful work. Apparent power, measured in volt-amperes (VA), is a combined measure of both real power and reactive power (which does not perform any useful work but is necessary for creating magnetic fields in inductive components).

The power factor, which ranges from 0 to 1, indicates how effectively electrical power is being converted into useful work output. A power factor of 1 (or 100%) signifies that all the power is being efficiently used for productive work, while a lower power factor indicates that some of the power is wasted, often due to reactive components in the circuit.

Understanding the power factor is vital for energy management and efficiency in electrical systems, as improving the power factor can lead to reduced energy costs and improved system performance.