farad

SI unit of electrical capacitance (how much electric charge a capacitor can store for a given voltage). One farad is a capacitance of one coulomb per volt. For practical purposes the microfarad (one millionth of a farad, symbol μF) is more commonly used.

The farad is named after English scientist Michael Faraday, and replaced the now obsolete unit the jar (so called because it represented the charge stored in a Leiden jar, the earliest electrical circuit). One farad equals 9 × 108 jars.