# joule (J)

Joule (J) is the unit of electrical, mechanical and thermal energy in the international system of units

.As electrical energy, one joule is equal to the work done

by acurrent

ofone ampere flowing through a resistance of one ohm for one second. Thus, one joule is equal to one watt-second (Ws), or 3,600 joules are equal to one watt-hour

, which inturn is equal to 860 calories (cal).

This irreversible generation of energy, based on thermoelectricity, is also known as the Joule effect. The joule is named after the British physicist James Prescott Joule (1818 - 1889).