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Definition of Impedance
1. Noun. A material's opposition to the flow of electric current; measured in ohms.
Generic synonyms: Electrical Phenomenon
Specialized synonyms: Ohmage
Derivative terms: Resistive
Definition of Impedance
1. n. The apparent resistance in an electric circuit to the flow of an alternating current, analogous to the actual electrical resistance to a direct current, being the ratio of electromotive force to the current. It is equal to R2 + X2, where R = ohmic resistance, X = reactance. For an inductive circuit, X = 2πfL, where f = frequency and L = self-inductance; for a circuit with capacity X = 1 ÷ 2πfC, where C = capacity.
Definition of Impedance
1. [n -S]
Medical Definition of Impedance
1. 1. Total opposition to flow. When flow is steady, impedance is simply the resistance, e.g., the driving pressure per unit flow; when flow is changing, impedance also includes the factors that oppose changes in flow. Thus, deviations of impedance, from simple ohmic resistance because of the effects of capacitance and inductance, become more important in alternating current as the frequency of oscillations increases. In fluid analogies (e.g., pulsatile flow of blood, to-and-fro flow of respiratory gas), impedance depends not only on viscous resistance but also upon compressibility, compliance, inertance, and the frequency of imposed oscillations. 2. Resistance of an acoustic system to being set in motion. (05 Mar 2000)
Lexicographical Neighbors of Impedance
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