What is electromotive force (emf) also known as?

Electromotive force, commonly referred to as emf, is a measure of the energy provided per charge by an energy source such as a battery or generator. It quantifies the ability of that source to produce an electric potential difference, which drives electric current through a circuit. This potential difference is what we commonly call voltage, and it is measured in volts (V).

The term emf emphasizes the source’s ability to create voltage, regardless of whether a current is flowing within the circuit or not. While resistance, current, and power are all important concepts in electrical systems, they each refer to different properties. Resistance relates to how much a material opposes the flow of current, current is the flow of electric charge, and power is the rate at which energy is consumed or produced in a circuit. Therefore, emf is best recognized as synonymous with voltage, highlighting its role in establishing the electric potential that is necessary for current flow.