Ohm's Law relates the three fundamental electrical quantities: voltage, current and resistance. Power
relationships are also given.
Click here for a much more extensive treatment of
Ohm's Law.

V = I · R 
I = V R 
R = V I 
P = I · V 
P = I^{2} R 
P = V^{2} R

I = Current (A) P = Power (W) R = Resistance (Ω) V = Voltage (V)
