### 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.