on 3/26/2002 7:17 PM, M R at [EMAIL PROTECTED] wrote: > the entire world is using kWh, MWh, GWh & > TWh making watt-hour the only unit of electricity.
Madan's statement above is simply not true. First, there are many aspect of electricity not all of which can be measured in energy units. Second, even limiting the discussion to electrical energy, the kilowatt-hour is certainly not the only unit. Electricity is a phenomenon. You don't "measure electricity", at all. You measure various aspects of it. You can measure electric field strength (in volts per metre), electric current (in amperes), the charge on a capacitor (in coulombs), the electric potential between two points in a circuit (in volts), the frequency of electric current (in hertz) and probably several others. NONE of these is energy and therefore NONE of them can be measured in kilowat-hours (or joules, either, for that matter). The amount of energy involved is only one aspect of electricity that can be measured. That is the aspect that is measured in kilowatt-hours. But the kilowatt-hour is far from the only unit used to measure electrical energy. The watt-second is also used. And certainly the joule is used by anyone who is using SI. (And aren't we all???) The fact that "all the world is using it" is irrelevant here, in addition to being not entirely true. Regards, Bill Hooper physics professor (retired), Florida, USA ======================== Keep It Simple - Make It Metric! ========================
