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Homework Help: Electromagnetic Fields and Effects of Oscillation

  1. Sep 29, 2011 #1
    The electrical circuits in a house run on alternating current. This is a current of electrical charges that oscillates back and forth at a frequency of 60 Hz. Do these currents produce magnetic fields? Explain. Do these circuits radiate electromagnetic waves? Why or why not?

    I don't have any relevant equations, we are talking about qualitative answers--not quantitative.

    My reasoning is this. If electrical charges move back and forth at a frequency of 60Hz then they are in fact 'moving' and would form a magnetic field. Since the magnetic field isn't chanigng however, it therefor wouldn't create an electric field (because they are caused by changing magnetic fields). So, I think I've got the first part of the question down: it does create magnetic fields. But, I'm not sure if the circuits radiate electromagnetic waves. Help me out, please!

    EDIT: Grammar
    Last edited: Sep 29, 2011
  2. jcsd
  3. Sep 29, 2011 #2


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    Welcome to PF,

    Any time charges accelerate, they radiate. This is common knowledge. But if you want to think about why, then consider that a charge moving back and forth is not a steady current (the velocity of the charge is not constant). Therefore, it doesn't give rise to a static magnetic field, but rather a time-varying one. And a time-varying magnetic field induces an electric field. A time-varying electric field induces a magnetic field. And so on and so forth. This is how EM radiation maintains itself and propagates.
  4. Sep 29, 2011 #3
    Thank you very much, this makes sense :)
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