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Doubts on Skin effect & Electricity

  1. Dec 27, 2009 #1
    Hi all! This is my first post :D

    I came across skin effect which blocks propagation of an em-wave within a conductor...
    But doesn't the energy generated at an electric plant reach our house through conductors flowing for over a 1000 miles sometimes?

    If I have to consider it just as an alternating voltage/electric field which makes the charge carriers to flow such long distance, then I have these 2 doubts:
    1. Can just 11000 volts be sufficient for pulling / pushing electrons in the conductor after thousands of miles from the source?
    2. Even though it is an alternating electric field at the source, while propogation, there will an alternating magnetic field around the conductor which makes it an em wave. And now the same skin effect should work here to to limit the propagation to just a few millimeters or cms...

    Thanks in Advance for whoever clears my doubts :P
     
  2. jcsd
  3. Dec 27, 2009 #2
    The interstate power line voltage in the U.S. is often over 700,000 volts. See
    http://en.wikipedia.org/wiki/Overhead_power_line
    Higher voltage reduces the current. The power line conductor diameter is small relative to the skin depth at 60 (or 50) Hz, so the skin loss is small. The actual power is carried in an em wave between the power line conductors (the Poynting vector), because the energy flow (magnitude and direction) is the vector cross product of the magnetic field and the electric field.. See
    http://en.wikipedia.org/wiki/Poynting_vector
    Bob S
     
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