Charts for the equations of Ohm’s Law usually consist of the fourfold relation between Voltage (Volts), Current (Amps), Resistance (Ohms), and Power (Watts). For each electrical quantity, there are three equations that represent it in terms of two others, making twelve equations total.
Ohm’s Law is really only between voltage, current, and resistance. Apparently, power is more correctly introduced by the formula for “Joule heating”.
Both voltage and current have been in two fourfolds previously (Four Basic Electrical Components and System Dynamics) but not power and resistance. Well, resistance did make an appearance as a relation between current and voltage.
The twelve equations can be generated by the following identities (where E = voltage, I = current, R = resistance, and P = power):
I*R/E = P/(I*E) = P*R/E^2 = R*I^2/P = 1
Google search for images for Ohm’s Law.
[*8.4, *8.5, *8.8, *8.9, *8.10]