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Physics -- Units and Concepts: Electricity |
In electricity we have something like force: electric potential difference, or "voltage". The unit of this electric force is the Volt, V, in honour of Alessandro Volta who invented the battery.
Volts make electric currents flow, they push the electric charge down the wire. Charge is measured in Coulomb, C. The intensity of an electric current is measured in electric charge per second. Current is then in C/s or Ampères, A, in honour of Ampère. One Ampère is a flow of 1 Coulomb electric charge per second.
The trick is to choose these units of V and C in such a way that the units of work and power are the same as for mechanical work.
To do work with an electric device, you need to push some electric charge through the device, for which you may need more or less voltage. A device can do the work by letting a large amount of charge through with little voltage applied to it, or a small amount under large voltage. The work unit is 1 Vx1 C = 1 Joule. If we do this per second we get electric power: 1 V x 1 C/s = 1 V x 1 A = 1 W. Electric power is volts times amps and of course the unit of power is the Watt.
Confusion...