What is the total charge on the surface?

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Homework Statement


A point charge q is embedded at the centre of a sphere of linear dielectric material (with susceptibility chi(subscript e) and radius R).

b)What is the total charge on the surface? [3 marks]
c) where is the compensating negative bound charge located? calculate it


The Attempt at a Solution



volume polarisation charge density=-div P
=1/r^2 d/dr((r^2)P) (partial derivative)
=1/r^2 d/dr [[(r^2 Q chi(e) epsilon0]/[4 pi epsilon(r) r^2]]
=1/R^2 d/dr [(q chi(e) epsilon0)/(4 pi epsilon (r))]
=1/R^2 *0
=0


surface charge polarisation density=[(q chi(e) epsilon0) r-hat.n]/(4 pi epsilon1 R^2)
=[(q chi(e) epsilon0)]/(4 pi epsilon1 R^2)

does that help to calculate the total bound charge on the surface at all?
because the surface polarisation charge density=0, the bound charge on the surface=0. three marks for saying just that?

please tell me if I'm wrong
 
Last edited by a moderator:
on Phys.org
, I'm not confident about this. c) The compensating charge is located in the interior of the sphere i.e. at the position of the point charge q.
 

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