What is low and high impedance and how does it relate to current and voltage? My friend keeps saying things like, it is a low impedance input, what does all this mean?
2007-02-21 05:55:10 · 6 answers · asked by a a 1 in Science & Mathematics ➔ Engineering
Impedance is the generalized resistance, used in alternating currents.
A higher impedance gives a weaker current than a lower one.
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2007-02-21 08:48:41 · answer #1 · answered by Thermo 6 · 0⤊ 0⤋
Technically, the others are more or less right. "Impedance" is a form of resistance. Impedance is the inductive, or capacitive reactance of a circuit to a frequency of some kind. For an audio circuit the frequency used to establish the 'impedance" of a device is 1000 Hz. A low impedance circuit would have a low dynamic resistance to the flow of electrical energy, volts or amps, in a circuit. Generally, a speaker output is going to be a low impedance circuit. The input to an audio device is generally a high impedance. Energy transfer, and reducing stray, unwanted signals are the reasons that these characteristics were chosen.
2007-02-21 17:17:05 · answer #2 · answered by Anonymous · 0⤊ 0⤋
In terms of input and output, impedance is the amount of resistance to current flowing in or out.
An ideal amplifier has a very high input impedance, and a very low output impedance. Very high and very low are just relative terms. A high impedance might be in the 10's or 100's of Kilo-ohms, while a low impedance might be 10 ohms or less.
A high impedance at the input of the amplifier means that the amplifier will see the majority of the signal voltage present at the input of the amplifier, with very little of the signal being lost to components in series with the input. With a low output impedance, the amplifier can deliver maximum power at the output without effecting the gain.
2007-02-21 06:28:01 · answer #3 · answered by joshnya68 4 · 0⤊ 0⤋
An impedance the the alternating current equivalent of ohm's law. If we use the symbol Z for impedance,
I (current) = V (voltage) / Z where both I can C are alternating current and voltage. For a given voltage, the higher the Z, the lower the current. They usually use the term impedance when dealing with audio or radio frequencies.
2007-02-21 06:01:19 · answer #4 · answered by Gene 7 · 0⤊ 0⤋
Impedence is Ohms - Measuments of resistance in a electrical circuit- Ohms law - I = V/R where I is the current, V is the potential difference, and R is a constant called the resistance. The potential difference is also known as the voltage drop, and is sometimes denoted by E or U instead of V. Electrical impedance, or simply impedance, is a measure of opposition to a sinusoidal alternating electric current.
2007-02-21 06:01:44 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Resistance.
The more resistance there is in an electric circuit, the less current and power you have.
"Resistance" is the word for direct current, "impedance" is for alternating current.
2007-02-21 06:00:59 · answer #6 · answered by morningfoxnorth 6 · 0⤊ 0⤋