Impedance is the complex-valued generalization of
resistance
Resistance may refer to:
Arts, entertainment, and media Comics
* Either of two similarly named but otherwise unrelated comic book series, both published by Wildstorm:
** ''Resistance'' (comics), based on the video game of the same title
** ''T ...
. It may refer to:
*
Acoustic impedance, a constant related to the propagation of sound waves in an acoustic medium
*
Electrical impedance, the ratio of the voltage phasor to the electric current phasor, a measure of the opposition to time-varying electric current in an electric circuit
**
High impedance, when only a small amount of current is allowed through
**
Characteristic impedance
The characteristic impedance or surge impedance (usually written Z0) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction in ...
of a transmission line
**
Impedance (accelerator physics) Impedance in Accelerator Physics is a quantity that characterizes the self interaction of a charged particle beam, mediated by the beam environment, such as the vacuum chamber, RF cavities, and other elements encountered along the accelerator or st ...
, a characterization of the self interaction of a charged particle beam
**
Nominal impedance
Nominal impedance in electrical engineering and audio engineering refers to the approximate designed impedance of an electrical circuit or device. The term is applied in a number of different fields, most often being encountered in respect of:
...
, approximate designed impedance
**
Impedance matching, the adjustment of input impedance and output impedance
*
Mechanical impedance, a measure of opposition to motion of a structure subjected to a force
*
Wave impedance, a constant related to electromagnetic wave propagation in a medium
**
Impedance of free space The impedance of free space, , is a physical constant relating the magnitudes of the electric and magnetic fields of electromagnetic radiation travelling through free space. That is, , where is the electric field strength and is the magnetic fiel ...
, a universal constant and the simplest case of a wave impedance
See also
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