How do watts, watt-hours, etc. relate to voltage, current, and resistance?
The Ampere (Amp A) is a measure of the rate at which current is flowing (charge per unit time). The Volt (V) is a measure of the energy potential across a circuit / device. The Watt (W) is the rate of energy conversion, which you get by multiplying V by A. (A KW is 1000 Watts) For a total energy quantity you multiply the rate in Watts by time in seconds, to get a value in Joules (J). The Kilowatt hour is a more practical term for domestic use, but 1KWh = 1000 x 3600 J i.e 3600 KJ or 3.6 MJ. Note that for AC current the voltage is measured as a root mean square average, because with alternating (+ve to -ve) current the mean average voltage is zero.
