Impedance
Impedance is the complex-valued generalization of resistance. 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 of a transmission line Impedance (accelerator physics), a characterization of the self interaction of a charged particle beam Nominal impedance, 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, a universal constant and the simplest case of a wave impedance See also