im·ped·ance

(ĭm-pēd′ns)

1. Symbol Z A measure of the total opposition to current flow in an alternating current circuit, made up of two components, ohmic resistance and reactance, and usually represented in complex notation as Z = R + iX, where R is the ohmic resistance and X is the reactance.

2. An analogous measure of resistance to an alternating effect, as the resistance to vibration of the medium in sound transmission.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

impedance

(ɪmˈpiːdəns)

1. (Electronics) a measure of the opposition to the flow of an alternating current equal to the square root of the sum of the squares of the resistance and the reactance, expressed in ohms. Symbol: Z

2. (Electronics) a component that offers impedance

3. (General Physics) Also called: acoustic impedance the ratio of the sound pressure in a medium to the rate of alternating flow of the medium through a specified surface due to the sound wave. Symbol: Za

4. (General Physics) Also called: mechanical impedance the ratio of the mechanical force, acting in the direction of motion, to the velocity of the resulting vibration. Symbol: Zm

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

im•ped•ance

(ɪmˈpid ns)

n.

1. the total opposition to alternating current by an electric circuit, equal to the square root of the sum of the squares of the resistance and reactance of the circuit and usu. expressed in ohms.

2. the ratio of the force on a system undergoing harmonic motion to the velocity of the particles in the system.

[1886]

im·ped·ance

(ĭm-pēd′ns)

A measure of the opposition to the flow of an electric current through a circuit of alternating current. Impedance is measured in ohms.

The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

ThesaurusAntonymsRelated WordsSynonymsLegend:

Noun

impedance - a material's opposition to the flow of electric current; measured in ohms

electric resistance, electrical resistance, ohmic resistance, resistivity, resistance

electrical phenomenon - a physical phenomenon involving electricity

ohmage - the ohmic resistance of a conductor

Translations

Impedanz

impedanssi

impedancija

impedancia

impedenza

impedance

[ɪmˈpiːdəns] N (Elec) → impedancia f

Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005

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References in periodicals archive

Applying a transmission line model based on the telegrapher's equations (as typically common in signal integrity considerations, except for when considering extremely high data rates, e.g., Serdes channels), one often-used general expression for the characteristic impedance of a lossy transmission line is:

Inside Signal Integrity: Impedance Control--Part 2

Additionally, pre-stack inversion is useful for redeveloping brownfield 'as it gives more details about reservoir properties' through providing 'multiple impedance attributes and more resolution about lithology, porosity, and the fluid filling the pores,' as Shady Negm, CEO of Earthtec, told Egypt Oil and Gas.

Pre-Stack, Post-Stack Inversion in Brownfields

The control performance and stability of the system are analysed by improving traditional voltage source impedance criterion to current source impedance ratio criterion.

Stability Analysis of Multi-Inverters Grid-Connected System Using Improved Current Source Impedance Ratio Criterion

Figure 2 shows the impedance response of the humidity sensors produced with varying PVDF nanofiber and ZnO mixtures.

High Performance and Moisture Stable Humidity Sensors Based on Polyvinylidene Fluoride Nanofibers by Improving Electric Conductivity

Contributors from metrology and other scientific and engineering areas describe impedance spectroscopy and its advanced applications in battery research, bioimpedance, measurement systems, and sensors.

Impedance Spectroscopy: Advanced Applications: Battery Research, Bioimpedance, System Design

Conventional acoustic impedance (AI) inversion, which is the product of P-wave velocity and density, assumes that the P-wave strikes the subsurface interfaces at normal incidence (Lindseth, 1979).

A modified approach for Elastic Impedance Inversion due to the variation in the value of K/Enfoque modificado de la Inversion de Impedancia Elastica con variacion del valor K

"Impedance matching is basically trying to match the headphone to the music source or the player that you use.

Sennheiser Hosts Inaugural Sound Forum in PH

There are two distinct MPP applications: (1), room acoustic applications, where high absorption coefficient is the target, and (2), duct and silencer applications, where surface impedance maximizing transmission loss (TL) is the target.

Additive Manufacturing of Silencers with Microperforates

The next section introduces the theory of bioimpedance and electrical impedance spectroscopy.

Assessment of Ripening Degree of Avocado by Electrical Impedance Spectroscopy and Support Vector Machine

In [4], a folded step impedance resonator (SIR) was used for the NBPF, but the insertion loss was high.

Design of a Suspended Stripline Narrow Bandpass Filter with Ultrawideband Harmonic Suppression

To investigate the effects of elastic and plastic strains on eddy current response in metals by experimental tools, uniaxial tensile loading is commonly applied in the tensioned samples and the impedance variation of the eddy current sensor (ECS), which is placed near the sample surface, is recorded during the entire tension process [14].

Characterization of Elastic and Plastic Behaviors in Steel Plate Based on Eddy Current Technique Using a Portable Impedance Analyzer