What is measured by the power factor in electrical systems?

Power factor is a crucial aspect of electrical systems, representing the relationship between active power, measured in watts, and apparent power, measured in volt-amperes. Active power is the power that actually does work in an electrical system, while apparent power is the product of the total voltage and current supplied in the circuit, regardless of whether the power is used effectively.

The power factor is calculated as the ratio of these two quantities and indicates how effectively the electrical power is being converted into useful work. A power factor of 1 (or 100%) means that all the power supplied is being used for productive work, whereas values below 1 indicate that some of the power is wasted, often due to reactive power components in the system. Understanding power factor is vital for optimizing energy efficiency and reducing costs in electrical installations.

This relationship is essential for engineers and technicians when designing and operating electrical systems because a low power factor can lead to higher energy losses and increased demand charges on utility bills.