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Homework Help: Electric Charge

  1. Jun 12, 2008 #1
    Hi all. I need some help.
    Without using Gauss's Law, I have to derive the formula for the electric charge for different cases.
    -I already did few cases such as:
    1. Infinite line of charge
    2. Semi - infinite line of charge
    3. Ring of charge
    4. Semi - Ring of charge or any arc of charge
    5. Disk of charge
    6. Infinite Sheet of Charge

    -I need to derive:
    7. Cylinder of charge
    8. Cone of charge
    9. Sphere of charge
    10. Shell of Charge

    I know that the basic "building block" for cases 7-10 is the ring of charge which I already have. Basically what I need is the setup of the integral for cases 7-10.

    Thank you

    Chris W
  2. jcsd
  3. Jun 12, 2008 #2
    It's just an exercise in different coordinates. A cylinder has constant r, varying z and phi/theta in cylindrical coordinate, a cone has varying z, r and phi/theta in cylindricalm a sphere has varying, r, phi, theta in spherical and a shell has constant r, varying phi, theta in spherical
  4. Jun 12, 2008 #3

    Yeah. Looks like I have all I need now I just have to set up the integrals.

    Thanks! wow that was quick ... lol

    please see what I have so far ... I hope all is good!

    Thank you one more time

    see attachment

    Attached Files:

  5. Jun 12, 2008 #4
  6. Jun 12, 2008 #5
    this is the rest of what I have so far

    sheet of charge can be viewed as the disk of charge and letting the R go to the infinify

    Attached Files:

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