Potential (f or V ).

The potential (f) any point is measured by the work required to bring unit positive charge from an infinite distance. Potential difference (V) between two points is measured by the work required to carry unit positive charge from one to the other. If the work is expressed in Joules and charge in Coulombs the potential difference is expressed in Volts. In practice, potentials are expressed relative to the earth which by convention is assigned a potential of zero volts. The potential difference between two points is commonly expressed as the difference in their potentials (volts) relative to that of the earth. GLOSSARY 269