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Conducting Shell

  1. Aug 20, 2005 #1
    In a conducting shell,with inner radius R1 and outer radius R2,and with charge Q at the centre,the Potential at surface is (kQ/R2),Why it is not (KQ/R1)?? :confused:
     
  2. jcsd
  3. Aug 20, 2005 #2

    Meir Achuz

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    All the charge on a conducting shell is on the outer surface.
     
  4. Aug 20, 2005 #3
    Meir,
    the charge Q present at the centre will induce -Q at the inner surface of shell and +Q at the outer surface of shell.
    So obviously there is charge on inner surface too.!
     
  5. Aug 20, 2005 #4
    There are charge on inner surface but is canceled by the center charge, and there are charge Q distribute on the surface. So we can see the shell as a charged shell that charge Q is on the surface.
     
  6. Aug 21, 2005 #5

    Meir Achuz

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    brasil is right. I misread the original question, and didn't realize there was a charge at r=0.
     
  7. Aug 21, 2005 #6
    That's okay Brasil but howcome,the same potential for outer surface becomes equal to that of inner surface.!
     
  8. Aug 22, 2005 #7
    We can see potential as work done by electric field (albeit this "work" isn't the same as Force do) There's no field inside the shell, hence the potential is all the same from the outer surface to the center.
     
  9. Aug 22, 2005 #8
    correctamundo

    ps : do you guys know the charge distribution in the shell if the inner charge is not at the center of the sphere (let us say it is 1 cm away from the center to the left side)...what is the charge distribution in the shell ? is it uniform ? this is a classic... :tongue2:

    marlon
     
  10. Aug 22, 2005 #9
    Of course it isn't uniform
     
  11. Aug 22, 2005 #10
    WRONG

    marlon
     
  12. Aug 22, 2005 #11

    SpaceTiger

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    Uh, if I'm visualizing this correctly, it's the same from the outer surface to the inner surface (since you're inside a conductor), but inside the inner surface, the potential goes as 1/r.
     
  13. Aug 22, 2005 #12

    SpaceTiger

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    The charge distribution on the inner surface would have to be non-uniform in order for there to be an electric field of zero inside the conducting shell. However, the distribution on the outer surface would be uniform. Conductors essentially "hide" the information about the charge inside them and that's why the Faraday Cage works to block electromagnetic waves.
     
  14. Aug 22, 2005 #13

    college application approved :approve:

    marlon

    ps : it has been a while, man, how have you been ?
     
  15. Aug 22, 2005 #14

    SpaceTiger

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    Pretty good, just chilling in Seattle for a few weeks. :biggrin:
     
  16. Aug 22, 2005 #15
    what exactly does chilling mean ? :wink:

    is it a grunge thing ?

    marlon
     
  17. Aug 22, 2005 #16

    SpaceTiger

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    Heh, I was a grunge freak in high school, but no, it just means I'm relaxing. But I guess that's not entirely true, since I'm here to work with an old advisor. :tongue2:
     
  18. Aug 22, 2005 #17
    ops! I type to quick that I didn't notice I write the wrong thing. You are right.
     
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