Lectures on Physics has been derived from Benjamin Crowell's Light and Matter series of free introductory textbooks on physics. See the editorial for more information....

Units of volt-amps

Question: Doorbells are often rated in volt-amps. What does this scombination of units mean?

Solution: Current times voltage gives units of power, P=I ΔV, so volt-amps are really just a nonstandard way of writing watts. They are telling you how much power the doorbell requires.

Last Update: 2010-11-11