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Unformatted text preview: on Chromium Lead Cobalt Aluminium Copper Nickel Platinum Silver Table 11.1.2: Paramagnetic, diamagnetic and ferromagnetic materials Skin effect With a linear conductor carrying a direct current, current density has the same value
at all points of the conductor cross section. With alternating currents, however, the
current is forced towards the surface. In the case of very high frequencies, the
current is practically restricted to a thin layer on the surface of the conductor, hence
the name skin effect. Skin effect means that a wire for a high-frequency alternating
current has a higher resistance than that for direct current.
If one assumes that the wire is made up of several conductors of lesser crosssection, then the mutual induction of such a conductor in the centre is greater than
that of one at the outer edge. The passing alternating current is thus forced to the
surface, i.e. the area with least alternating current resistance. 162 © Festo Didactic GmbH & Co. KG • FP 1110 11. Physical fundamentals Penetration depth The skin thickness, within which the current amplitude has decreased by the amount
1/e (= 1/2.718), is described as the penetration depth d. The...
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This note was uploaded on 11/01/2012 for the course CHEMICAL 102 taught by Professor Jamesrodriguez during the Spring '12 term at Universidad Politécnica de Cartagena.
- Spring '12