What is a watt?

Watt (named in honor of James Watt) is the practical electrical unit of activity or rate of doing work. It is measured by the product of the voltage or electromotive forcé 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 3,000 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, equal to 1,000 watts.