1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

EM Waves

  1. Feb 27, 2005 #1
    Hi, I have the following question on my problem sheet, and I just want to check that my answer to it is correct as I need to use the result in a later problem. If someone could confirm it is correct, or point out mistakes/erros that would be great.

    =======
    Q. Derive the wave equation for E in empty space (Form the curl of Maxwell II and use a vector identity.). Find the condition that the plane wave E = eyEycos(wt - kx) is a solution (k=2pi/lamda). Use Maxwell II to find the B field associated with this electric field.
    =======

    A. I've done the derivation fine to get:

    Laplacian E = epsilon-0.mu-0. d^2E/dt^2 [these are partial derivatives]

    this is the same as d^2E/dx^2 = (1/c^2).(d^2E/dt^2) which can be solved using separation of variables to get E = eyEycos(wt - kx).

    To find the associated B field, we used Maxwell II, ie. curlE = -dB/dt.

    CurlE = -keyEysin(wt - kx)

    B = integral - [curl E] dt

    B = k/w. eyEycos(wt - kx)

    =======

    Thanks
     
  2. jcsd
  3. Feb 27, 2005 #2

    dextercioby

    User Avatar
    Science Advisor
    Homework Helper

    [tex] \vec{B}=-\int dt \nabla\times\vec{E} [/tex]

    What is the curl of [itex] \vec{E} [/itex]...?And then evaluate the integral correctly.

    Daniel.
     
  4. Feb 27, 2005 #3
    Isn't the curl of E in this case, just the value of E calculated earlier, integrated wrt x?
     
  5. Feb 27, 2005 #4

    dextercioby

    User Avatar
    Science Advisor
    Homework Helper

    That curl is a vector and should have 2 components,namely on [itex] Ox_{1}[/itex] and [itex] Ox_{3} [/itex] axis of coordinates...

    So it's incorrect what you have written.Please do the calculations again.

    Daniel.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: EM Waves
  1. EM waves (Replies: 3)

  2. EM Waves and EM Pulses (Replies: 4)

  3. Em waves (Replies: 6)

  4. EM waves (Replies: 4)

Loading...