Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is effective conductivity?

  1. Apr 21, 2012 #1
    What is "effective" conductivity?

    In one of my homework problems (This ISNT a homework help question! It is conceptual) It says to find the "effective" conductivity.

    What is the difference between conductivity and effective conductivity? Is there any difference?
     
  2. jcsd
  3. Apr 21, 2012 #2
    Re: What is "effective" conductivity?

    At higher frequencies, the depth of penetration of a signal into the center conductor of a coaxial cable is limited to the skin depth δ. See http://en.wikipedia.org/wiki/Skin_effect. So if the radius of the center conductor is r, then the effective conducting area is 2 πrδ, which is less than the total conductor area πr2.
     
  4. Apr 21, 2012 #3
    Re: What is "effective" conductivity?

    Thanks a lot!!
     
  5. Apr 21, 2012 #4

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Re: What is "effective" conductivity?

    Is this AC or DC? Is this in simple or composite materials? What is the context.
     
  6. Apr 21, 2012 #5
    I was given a wave traveling though a lossy dielectric medium in a transmission line. So this is AC.
     
  7. Apr 21, 2012 #6

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Re: What is "effective" conductivity?

    Then Bob's answer is right. If it were DC, it would have been something else.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook