Ohms Law
 Why its important to you - by Eddie Runner

If your going to be doing anything with electronics, Ohms law is one of the most important things you can learn.  In school, Ohms law is gone over and it is always boring as hell. For that reason I think is why most installers don't pay much attention to Ohms Law. I print the Ohms Law chart below and post it in the installation bay and whenever I can I will point out to the installer trainees why whatever task they are doing while installing relates to the chart. Forinstance, to figure out how much power an amplifier is delivering to a speaker you can simply measure the voltage at the speaker terminals and follow the equation. voltage times voltage divided by the impedance of the speaker, so if you measured 10 volts and had it paying a 4 ohm speaker the wattage would be 25watts. Simple!!!  You can also use the chart to help you with current draw, wire sizes, and about anything else electrical while installing.

PRINT IT, HANG IT, USE IT! you will be surprised how much sense it makes!