Which SI unit measures the difference in electric potential?

The SI unit that measures the difference in electric potential is the volt. Electric potential, often referred to as voltage, represents the work done per unit charge in moving a charge between two points in an electric field. Essentially, it quantifies the potential energy available to push electric charges through a circuit.

When a difference in electric potential exists, it indicates how much energy is needed to move a charge from one point to another, making it a fundamental metric in understanding electrical circuits and systems. The volt is defined as one joule per coulomb, emphasizing the relationship between energy and charge.

In contrast, amperes measure the flow of electric current, watts measure power (the rate at which work is done or energy is transferred), and ohms indicate electrical resistance. These units play vital roles in electrical calculations but do not measure electric potential itself. Thus, volts is the correct choice for the unit that reflects the difference in electric potential.