Basic Units

Energy

As has been said, voltage is related to energy and the voltage that must be applied across the conductor to make the electrons move. This energy (W), measured in Joules , is equal to the voltage difference across which the charge moves. So, W=QV. In practical terms, when a voltage is applied across a conductor, this energy QV is equal to the heat energy that is released in the conductor: if we were to measure the total amount of charge moving through (or in or out - they should all be the same) of the conductor then this would be Q.