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Homework Help: Electric power

  1. Aug 9, 2006 #1
    R= pl/A
    what does p and l stands for?
  2. jcsd
  3. Aug 9, 2006 #2
    p is the resistivity of a material(ohms.cm). Every material normally has a set value for it. l is the length of the material.
  4. Aug 9, 2006 #3
    thank you
    But if i had a distance of 100 km ,do i replace "l" with d and convert it to metres?
  5. Aug 9, 2006 #4
    from my experience with this equation(electronic subject) we had "l" in cm, but that was because we had "p" in ohm.cm for example

    R = pl/A ----> ohms = [(ohms.cm)(cm)]/cm(^2)
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