Potential of a spherical shell (non-uniform charge density)

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SUMMARY

The discussion focuses on calculating the electric potential and electric field of a spherical shell with a non-uniform surface charge density, represented by the angle θ from the top of the sphere. Participants emphasize the importance of incorporating charge density into the equations to derive meaningful results. The challenge lies in determining the potential and field both inside and outside the sphere while ensuring continuity across the boundary. The conversation highlights the need for a deeper understanding of charge distributions and their effects on electric fields.

PREREQUISITES
  • Understanding of electric potential and electric field concepts
  • Familiarity with spherical coordinates and charge density
  • Knowledge of Gauss's Law and its applications
  • Basic proficiency in calculus for solving integrals related to charge distributions
NEXT STEPS
  • Study the derivation of electric potential from surface charge distributions
  • Learn about Gauss's Law and its application to spherical symmetry
  • Explore the concept of continuity in electric fields and potentials
  • Investigate the effects of non-uniform charge densities on electric fields
USEFUL FOR

Students and educators in physics, particularly those focusing on electromagnetism, as well as anyone involved in solving problems related to electric fields and potentials in non-uniform charge distributions.

SquidgyGuff
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Homework Statement


Given a spherical shell of radius R and the surface charge density
gif.gif
(
gif.gif
being the angle from the top of the sphere
gif.gif
and
gif.gif
being a constant) find the electric potential
gif.gif
and the electric field
gif.gif
inside and outside the sphere. Check that both the potential is continuous inside and outside the sphere and that
gif.gif
inside and out. I made this little diagram to illustrate.
sphere_by_k4l3b-d98wxw3.png


2. Homework Equations

gif.gif

gif.gif


The Attempt at a Solution


I can't even understand this problem. I feel like the point of interest shown in the diagram should be on the shell so that
gif.gif
can return a meaningful value, but I need to find the potential and electric field everywhere, so it can't be on the sphere.
 
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Hello Guff,

I notice that your problem statement mentions a charge distribution on the surface of the sphere, but that there is no equation where charge or charge density plays a role. Is there something you can add to your 'toolbox' ?
 
BvU said:
Hello Guff,

I notice that your problem statement mentions a charge distribution on the surface of the sphere, but that there is no equation where charge or charge density plays a role. Is there something you can add to your 'toolbox' ?
If I looked at the charge distribution a point charge the field would look like this
%5Cfrac%7B%28%5Csigma_%7B0%7Dcos%5Ctheta%29%284%5Cpi%20R%5E%7B2%7D%29%7D%7Br%5E2%7D%5Chat%7Br%7D.gif
, but I know that isn't correct because I believe the total charge is zero. because half of the values of
gif.gif
are negative and the other half are positive.
 
I still don't see how you want to find the field or the potential at a point in space.
Where exactly on the sphere is ##\cos\theta## negative ?
 

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