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Interference from two radio antennae - simplistic and workings include

  1. Apr 23, 2013 #1
    ImageUploadedByPhysics Forums1366732033.684444.jpg

    ImageUploadedByPhysics Forums1366732191.354568.jpg

    Is this correct ?

    I have an issue for the minima formula when n=1 I get theta = 90 degrees.

    This doesn't make any sense.

    Is my method correct ?

    Attached Files:

  2. jcsd
  3. Apr 23, 2013 #2


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    Your general method is correct, but your formula for the minima is incorrect. Check your notes or text.
  4. Apr 23, 2013 #3
    The formulas listed were in my notes.

    Okay, for minima : 2λsinθ = mλ m=0.5,1.5,2.5,3.5...

    This would give me the required non-integr half wavelengths for a minima, correct ?

    EDIT : Hence m =0.5 would mean the first minima is at 30 degrees.

    maxima : 2λsinθ = nλ n = 0,1,2,3,4,5....

    For n =1 I still get theta to be 90 degrees.... I dont see what I'm doing wrong.
  5. Apr 23, 2013 #4

    rude man

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    Your minima formula is wrong.
  6. Apr 23, 2013 #5
    Can you check the post above yours, please ?
  7. Apr 23, 2013 #6

    rude man

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    No. 2sin(theta) = 0.5 does not yield theta = 30 deg.

    No. 2sin(theta) = 1 does not yield theta = 90 deg.
  8. Apr 23, 2013 #7
    Ah, God, silly mistakes.... Forgive my lapse in concentration. Its pretty late where I am right now.

    I've understood this question now. Thank you.
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