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Physical meaning of parts of electromagnetic wave

  1. Sep 24, 2010 #1

    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)
  2. jcsd
  3. Sep 24, 2010 #2
    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.
  4. Sep 24, 2010 #3


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    Staff: Mentor


    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.

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