a unit of electrical energy equal to the work done when a current of one ampere passes through a resistance of one ohm for one second
A unit of work which is equal to 10^7 ergs (the unit of work in the C. G. S. system of units), and is equivalent to one watt-second, the energy expended in one second by an electric current of one ampere in a resistance of one ohm; also called the absolute joule. It is abbreviated J or j. The international joule is slightly larger, being 1.000167 times the absolute joule. The absolute joule is approximately equal to 0.737562 foot pounds, 0.239006 gram-calories (small calories), and 3.72506 x 10^-7 horsepower-hours, and 0.000948451 B.t.u.
James Prescott Joule. English physicist who established the mechanical theory of heat and discovered the first law of thermodynamics (1818-1889)