How can the power factor of an electrical system be determined?

The power factor (PF) is a crucial measure of how effectively an electrical system is using the power supplied to it. The correct method to determine the power factor involves calculating the ratio of real power to apparent power. Real power, measured in kilowatts (kW), represents the actual power consumed by the circuit to perform work, whereas apparent power, measured in kilovolt-amperes (kVA), is a combination of both real power and reactive power, which does not perform any useful work but contributes to the total current flowing in the system.

Using the formula PF = Real Power (kW) / Apparent Power (kVA) provides a clear representation of the efficiency of the electrical system. If the power factor is close to 1, it indicates that most of the power is being used effectively; lower values signify inefficiencies often caused by inductive loads, such as motors. This formula appropriately quantifies the relationship between the energy actively consumed and the total energy available, hence being the method to accurately determine the power factor of an electrical system.

In contrast, measuring voltage and current alone does not account for the phase difference between them, which is essential in power factor determination. Averaging the current over time does not provide a