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Old 04-05-2019, 11:23 AM
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Mr Cox
 
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Originally Posted by Pond Skipper View Post
Skin Effect:
As Voltage pushes the current density is largest near the surface of the conductor and decreases within the core of the conductor.
Silver is the best conductor of electricity because it contains a higher number of movable atoms.
Silver it also has the highest thermal conductivity of any element.
Gold has a much higher corrosion resistance.
I'm sorry, I happen to teach physics at University level, and that's just wrong on so many levels....

Yes, there is a "skin" effect i electrical wires subjected to AC currents, but it only becomes important at high frequencies (MHz range). The electrical current carried by electrons is then located near the surface of the wire and not the whole cross-sectional area is being active. In DC applications, like when we use a battery do heat the glow plug, there is no skin effect and the whole cross sectional area of the wire is being used.

The electrical conductivity of silver is only marginally higher than for copper (at room temp.), and it is high for all of the noble metals and other free-electron like metals. It is the electrons in the free-electron gas that carries the current and this is fairly similar for the all the noble metals (mono-valent and free-electron like). The transition metals on the other hand (like nickel and palladium etc.) have a lower electrical conductivity due the partially filled d-bands. These electron have a large effective band-mass and therefore do not contribute much to the electrical conductivity. In addition the unfilled d-states will provide an additional scattering channel for the free-electron gas, thus lowering the mobility of these as well.

Last edited by Mr Cox; 04-05-2019 at 11:36 AM.
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