Which unit measures real power in electrical systems?

The unit that measures real power in electrical systems is the Watt (W). Real power, also known as active power, represents the actual power consumed by electrical devices to perform work, such as illuminating a lightbulb or powering a motor. This unit quantifies the rate at which energy is used or converted into work over time.

When dealing with electric circuits, real power is calculated in terms of voltage (volts) and current (amperes), taking into account the phase difference between them. This distinction is significant because it allows us to distinguish real power from reactive power, which is measured in VARs (volt-amperes reactive) and relates to energy storage in inductors and capacitors without performing any useful work.

Volt measures electric potential, while Ohm is a measure of resistance in a circuit. Var is used for reactive power, which is essential in understanding the overall power factor but does not quantify the actual energy consumed in performing work. Thus, Watt is the correct unit for real power, correctly aligning with its definition and role in electrical systems.