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Homework Help: Finding electric potential of a sphere with a given volume charge density

  1. Sep 29, 2009 #1
    1. The problem statement, all variables and given/known data
    the volume charge density Pe= Po (1- (r^2/r0^2))
    the sphere has a radius of r0
    and r is measured from the center
    for a point P inside the sphere (r<r0), determine the electric potential V if V=0 at infinity

    2. Relevant equations
    E= Qencl/ eps0*A= kQ/r^2
    Qencl= int(Pe*4pir^2) dr
    -int(E)= V

    3. The attempt at a solution
    first i found Qencl and evaluated it from 0 to r.
    Qencl= 4pi*p0 (r^3/ 3 - r^5/5r0^2)
    Then E= Po/eps0 ((r/3)- r^3/ 5r0^2)
    then the -integral of E= V= p0/eps0 ( (r^2/ 6) - (r^4/20r0^2) - (7r02/60))
    but this is the worng answer..any help?
  2. jcsd
  3. Sep 30, 2009 #2


    User Avatar
    Homework Helper

    Hi citra, welcome to PF.
    You have given volume charge density. But it does not appear correct. Can you check it.
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