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Homework Help: I get confused with the question

  1. Oct 22, 2004 #1
    Here's the question,

    A half wave dipole aerial is used to receive FM waves of frequency 120MHz.What is the most effective length of the aerial?

    (Speed of electromagnetic waves =3.0 x 10^8)

    I can't understand with the word 'half wave dipole aerial' ,is that means vibrations in air column,in an open end tube or both end-opened tube ?

    wavelength = 3 x 10^8 / (120 x 10^6)
    = 0.025m

    then I get stuck here,cannot find the lenght.

    Can anybody help me ?
    Last edited: Oct 22, 2004
  2. jcsd
  3. Oct 22, 2004 #2


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    Staff Emeritus
    Science Advisor
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    A half-wave dipole antenna or aerial means that the whole length of the aerial equals to half of the wavelength. This is similar to having a fundamental wavelength in a standing wave air tube with both ends being open.

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