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

Homework Help: Physics 2 coaxial potential help

  1. Jul 5, 2010 #1
    Physics 2 coaxial potential help!!!

    https://wug-s.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?cc/DuPage/phys2112/summer/homework/Ch-22-E-Potential/IE_cylindersV/coax.gif [Broken]

    The diagram above shows a coaxial cable. The inner conductor has radius a = 0.0025 m. The outer conductor is a cylindrical shell with inner radius b = 0.0075 m, and outer radius c = 0.008 m from the center. Both conductors are coaxial. For every length L = 10 m of cable, there is a total charge q = 2.8e-008 C on the inner conductor and a total charge of Q = -5.6e-006 C on the outer conductor.

    Determine the electric potential difference between the labeled points A and B.

    PLEASE 've been working on this problem for about THREE hours, and I still can't get it!!! I'm so confused. Please please please!

    I tried using the voltage equations from c to b and then adding it w/the voltage from b to a. and it's wrong!!
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jul 5, 2010 #2
    Re: Physics 2 coaxial potential help!!!

    I think you may find first E for r>=c.
    Please use Gauss law.
    Integral of E from r=c to infinity will give potential at r=c.
    Use the condition that potential at infinity = 0.
    Go the same way to the center.
    Last edited: Jul 5, 2010
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook