Ohms Law Pie Chart

Impedance in general is a complex number that can be calculated by using formulas for series and parallel connections. With known complex impedance, current phasor is Ĩ=V/Z. This pie chart ("wheel") illustrates relationships between voltage, current, impedance and power in linear networks with a sinusoidal input. These formulas are adaptations of Ohm's law and Joule's law for AC signals. In this "power wheel":
V - rms voltage (volts);
I - rms current (amps);
Z - magnitude of impedance (ohms);
S - apparent power (volt-amps).
By knowing any two values of V, I, Z or S, you can find the values of the remaining quantities.
For a pure resistor Z=R, I=V/R, and S=P, where R - resistance, P - active power.