aldav53, it is called ohm's law, day 1 theory after algebra class. However the is a heck of difference between the terminals of a service transformer, and a branch circuit with 50-feet of #12 AWG wire after the main panel.

To learn this difference simply short out the terminal from L-N or L-L on a service transformer, then repeat at a receptacle (use an apprentice to make the connections). Measure the fire-ball produced from both and see if there is any measurable difference. If so, why? [Linked Image]