Physical meaning of parts of electromagnetic wave


by littlepapa87
Tags: electromagnetic wave
littlepapa87
littlepapa87 is offline
#1
Sep24-10, 02:13 PM
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in

E = E_0exp i(k dot r - wt) or E = cos(k dot r - wt)

what does k dot r physically represent? Can r be any position in space or must it lie on the wave?

(I physically understand what a dot product is)
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Dr Lots-o'watts
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#2
Sep24-10, 03:06 PM
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That's a plane wave, it occupies all of space.

If you want a beam that is localized along a line, E_0 has to be a function of distance from the line.
jtbell
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#3
Sep24-10, 05:19 PM
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Quote Quote by littlepapa87 View Post
Can r be any position in space
Yes.

or must it lie on the wave?
A 3-dimensional plane wave fills space. It doesn't lie "along" a line or other single path. See the diagram and associated instructions in the following post for a more realistic picture of a plane electromagnetic wave than you see in many textbooks.

http://www.physicsforums.com/showpos...90&postcount=6


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