Watt

Watt, the name of the electrical unit of activity or rate of doing work. It is measured by the product of the voltage or electromotive force of the source into the current supplied. Thus a dynamo which is yielding 30 amperes at a voltage of 100 is working with an activity of 3000 watts. The watt is equal to 0.735 foot-pound per second; so that one horse-power per second is equal to 746 watts. It is customary to use the kilowatt as the practical unit. It is equal to a thousand watts or 1.2 horse-power per second. See ELECTRICITY, OHM, VOLT.