What is potential difference measured in?

Potential difference is the work done per unit charge. A potential difference of 1 Vmeans that 1 joule of work is done per coulomb of charge. ( 1 V = 1 J C-1) Potential difference in a circuit is measured using a voltmeter which is placed in parallel with the component of interest in the circuit.

The potential difference is the work done per unit charge. A potential difference of 1 V means that 1 joule of work is done per coulomb of charge. ( 1 V = 1 J C-1) The potential difference in a circuit is measured using a voltmeter which is placed in parallel with the component of interest in the circuit.

Source: physicsnet.co.uk