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Name: Ray
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Question:
What is the direction of electron flow on different metals and where can I find a chart of them? For example - It is my understanding that electrons flow in a straight line on silver and steel but spiral around a copper conductor. What is the direction of flow around tin or other metals?



Replies:
Ray

For direct currents:
Currents in a metal induced by an electric field flow
From the positive pole to the negative pole for positive current
From the negative pole to the positive pole for electron current.
It just depends on how you consider if current is negative or positive charges.
The results are the same in the end.

For direct current in metals, the path is direct from one pole of the electric field to the other, The electric field being induced by a voltage potential.

Please refer to the following URL for more detailed information:

http://en.wikipedia.org/wiki/Metal

A different effect occurs for alternating currents: It is called the skin effect. In short,
Skin effect is the tendency of an alternating electric current (AC) to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core. That is, the electric current tends to flow at the "skin" of the conductor, at an average depth called the skin depth. The skin effect causes the effective resistance of the conductor to increase with the frequency of the current because much of the conductor does little. Skin effect is due to eddy currents set up by the AC current. At 60 Hz in copper, skin depth is about 8.5 mm. At high frequencies skin depth is much smaller.

Methods to minimize skin effect include using specially woven wire and using hollow pipe-shaped conductors.

Please see the following URL for more details.

http://en.wikipedia.org/wiki/Skin_effect

You should also read about eddy currents at:

http://en.wikipedia.org/wiki/Eddy_current

But in general, current passes through metals in a uniform manner.

Sincere regards,

Mike Stewart



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