Reactance, resistance and impedance

[Dean820]

Could someone please help me out with this question, I can't find it everywhere in my book. Its a question I need to know for my exams as well.

Q. Distinguish between reactance, resistance and impedance and illustrate their relationship on an impedance phasor diagram.

 

[chroot]

Well, you're aware that a phasor diagram represents periodic signals by a vector on a two-dimensional plane.

One of the dimensions (usually the horizontal dimension) is taken to be pure resistance, with a phase angle between voltage and current of zero degrees. A resistor is a purely resistive device.

The other dimension (usually the vertical dimension) is then reactance. A reactive load has an I-V relationship such that they are either 90 degrees or 270 degrees out of phase. Capacitors and inductors are purely reactive devices.

An impedance is any combination of pure resistance and pure reactance summed together.

- Warren

 

[Dean820]

Thanks for the help.