Impedance

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What Does Impedance Mean?

Impedance (Z), in electrical devices, refers to the amount of opposition faced by direct or alternating current when it passes through a conductor component, circuit or system. Impedance is null when current and voltage are constant and thus its value is never zero or null in the case of alternating current.

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Techopedia Explains Impedance

Impedance is often mistakenly said to be the same as resistance, which is not correct. Impedance is a two-dimensional quantity comprising resistance (real component vector) and reactance (imaginary component vector). Impedance is also known as the frequency domain ratio of voltage and current. Frequency is involved because of alternating current (AC) whose sinusoidal wave is generated upon a certain frequency which directly or indirectly affects electrical components such as capacitors and inductors, whose resistance varies with frequency of the power source provided.

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Margaret Rouse
Technology expert
Margaret Rouse
Technology expert

Margaret is an award-winning writer and educator known for her ability to explain complex technical topics to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles in the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret’s idea of ​​a fun day is to help IT and business professionals to learn to speak each other’s highly specialized languages.