1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
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: Gauss' Law for a plane

  1. Jun 7, 2012 #1
    The electric field 0.475m from a very long uniform line of charge is 830 N/C.

    How much charge is contained in a section of the line of length 3.00cm?

    My solution:
    the Electric field from an infinite plane is

    E=σ/(2*ε0), so σ=E*ε0*2=1.47*10^-8



    This answer is showing to be wrong
  2. jcsd
  3. Jun 7, 2012 #2
    Just realized my problem was that my work was for a plane, not a line of charge. I'm not sure how to solve this for a line of charge though
  4. Jun 7, 2012 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Education Advisor

    A line charge has a cylindrical symmetry, so apply Gauss's Law using a cylinder as your Gaussian surface.
  5. Jun 12, 2012 #4
    Thanks for the help, forgot to reply at the time due to my astonishment that I had not thought of that.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook