See Also: Impedance(medicine)
impedance(dictionary)
impedance(dictionary)
cardiography, impedance(medicine)
electric impedance(medicine)
impedance angle(medicine)
acoustic impedance(medicine)
plethysmography, impedance(medicine)
Impedance plethysmography(health)
electrical impedance(encyclopedia)

impedance (iou)



impedance noun. L19.
[from IMPEDE verb + -ANCE.]
Electricity. The combined opposition to the passage of an (alternating) electric current exerted by the resistance (R) and the reactance (X), measured as the ratio of the electromotive force to the resulting current, and representable as Z=(R2+X2) or as a complex number R+jX. L19.
Mechanics & Acoustics. Any of several analogous properties of oscillatory mechanical systems that represent the force, pressure, etc., necessary to produce a given speed, rate of flow, etc. E20.
acoustic impedance the ratio of the pressure over an imaginary surface in a sound wave to the rate of flow across it. mechanical impedance the ratio of the force in the direction of motion to the velocity of the vibration. specific acoustic impedance the ratio of the pressure at any point in a sound wave to the resulting particle velocity.