What unit is used to measure the efficiency of transformers?

The efficiency of transformers is commonly expressed in terms of kVA, or kilovolt-amperes. This unit represents the apparent power in an electrical circuit, combining both voltage and current without considering the phase angle, as it relates to real power. Transformers are designed to operate at high efficiency in converting electrical energy from one voltage to another, and the kVA rating indicates their capacity to handle loads without respect to power factor. Therefore, using kVA provides a clear representation of the transformer's ability to transfer power efficiently under varying load conditions.

Watt measures real power, while Volt measures electrical potential, and Ohm indicates resistance. These units can relate to different aspects of electrical systems but do not specifically encapsulate transformer efficiency in the same comprehensive manner that kVA does.