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Name: Marco
Status: other
Grade: other
Location: Outside U.S.
Country: USA
Date: Summer 2012


Question:
Can an electromagnetic wave travel through a copper conductor? Does the propagation of an electromagnetic wave through a copper conductor require and electric current?

Replies:
Hi Marco,

Good questions, a bit broad in nature. Without having any specifics: No, if speaking about radio waves, the copper(Cu) will tend to pick up the magnetic component and generate electromotive force. A Cu mesh is an excellent EM wave sink. Yes, if speaking about inductive effects. Collapsing magnetic fields in an unprotected relay or toroid transformer are well known to induce an EMF so that semiconductor circuitry may be "fried".

An electromagnetic wave may generate a current in a Cu conductor. Cu(a low Resistance) may conduct electrons in an electromotive force vector having both electronic(Voltage) and magnetic(Amperage) field components. The E = IR equation must occur all at once. Induction occurs as the result.

Strictly, the fields may be outside of the Cu. But if the electrons are moving deep(only under high I conditions) in the Cu or if the Cu is wrapped as strands, then presumably there would be cutting of the fields through the very Cu they are traveling through.

Hope this helps. Peter E. Hughes, Ph.D. Milford, NH


You have to keep in mind that “an electromagnetic wave” should be “electromagnetic waves”. That is, electromagnetic waves come with different wavelengths – from x-rays, through the visible range (light), all the way to radio waves. The propagation properties vary with wavelength. See the web sites:

http://en.wikipedia.org/wiki/Electromagnetic_radiation ; http://pfaphysics.com/Site/Physics_Notes_files/TypesofHeatXfer.pdf ;

You can find a wealth of information on the transport of electromagnetic waves in metals by searching: electromagnetic waves in metals.

The short answer to your inquiry is “yes”, but the details of the conditions is more complicated.

Vince Calder


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