IMPEDANCE

Etymology

Noun

impedance (countable and uncountable, plural impedances)

The act of impeding; that which impedes; a hindrance.

(physics) A measure of the opposition to the flow of an alternating current in a circuit; the aggregation of its resistance, and inductive and capacitive reactances; the ratio of voltage to current treated as complex quantities.

(physics) A quantity analogous to electrical impedance in some other energy domain

(physics, usually with “mechanical”) a measure of opposition to motion of something subjected to a force; the ratio of force to velocity treated as complex quantities.

(physics, usually with “acoustic” or “sound”) the ratio of sound pressure to volume flow rate treated as complex quantities.

(by analogy, software engineering, usually with “mismatch”) a measure of the opposition caused by differences between two paradigms, especially between object-oriented development and relational databases

Usage notes

Impedance is universally given the symbol Z in technical works which is often used as a synonym for the word even in running text.

Source: Wiktionary


Im*ped"ance, n. [Impede + -ance.] (Elec.)

Definition: 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 = 2pfL, where f = frequency and L = self-inductance; for a circuit with capacity X = 1 Ă· 2pfC, where C = capacity.

Source: Webster’s Unabridged Dictionary 1913 Edition



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Word of the Day

30 April 2024

NURSE

(verb) treat carefully; “He nursed his injured back by lying in bed several hours every afternoon”; “He nursed the flowers in his garden and fertilized them regularly”


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Coffee Trivia

Plain brewed coffee contains almost no calories, while coffee with dairy products, sugar, and other flavorings is much higher in calories. An espresso has 20 calories. A nonfat latte has 72, while a flavored one has 134.

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