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!

Disk and Electric Field's Direction

  1. Jan 26, 2007 #1
    1. The problem statement, all variables and given/known data

    A thin disk with a circular hole at its center, called an annulus, has inner radius R1 and outer radius R2. The disk has a uniform positive surface charge density omega on its surface.

    Figure's link: http://i131.photobucket.com/albums/p289/SoaringCrane/yf_Figure_21_421.jpg

    Find the direction of the electric field E. Consider points above the annulus in the figure.

    2. Relevant equations

    This part of the question is really conceptual.

    3. The attempt at a solution
    Since the disk's overall charge is positive, the force of a positive test charge above the annulus would be directed away from the hole. Therefore, the electric field's direction would be in the positive x-direction??

  2. jcsd
  3. Jan 26, 2007 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    You are correct but can you show it using a vector diagram?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Disk and Electric Field's Direction