Electrical Impedance - Ohm's Law

Ohm's Law

The meaning of electrical impedance can be understood by substituting it into Ohm's law.

The magnitude of the impedance acts just like resistance, giving the drop in voltage amplitude across an impedance for a given current . The phase factor tells us that the current lags the voltage by a phase of (i.e., in the time domain, the current signal is shifted later with respect to the voltage signal).

Just as impedance extends Ohm's law to cover AC circuits, other results from DC circuit analysis such as voltage division, current division, Thevenin's theorem, and Norton's theorem can also be extended to AC circuits by replacing resistance with impedance.

Read more about this topic:  Electrical Impedance

Famous quotes containing the word law:

    The image cannot be dispossessed of a primordial freshness, which idea can never claim. An idea is derivative and tamed. The image is in the natural or wild state, and it has to be discovered there, not put there, obeying its own law and none of ours. We think we can lay hold of image and take it captive, but the docile captive is not the real image but only the idea, which is the image with its character beaten out of it.
    John Crowe Ransom (1888–1974)