What is the unit of electromotive force known as?

The unit of electromotive force is known as the volt. Electromotive force (emf) refers to the energy provided by a source of electric energy per unit charge. It is fundamental to understanding electrical circuits, as it represents the potential difference that drives current through a conductor. One volt is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power. This unit is crucial in the field of power engineering, as it helps engineers calculate and manage electrical systems, ensuring they operate efficiently and safely.

The other units mentioned, though essential in their respective contexts, do not measure electromotive force. Watt measures electrical power, ohm measures electrical resistance, and ampere measures electrical current. Each of these units plays its own role in the broader understanding of electrical theory and practice, but the volt specifically quantifies the driving force behind the electrical current in a circuit.