Electrodynamics - finding potential of a non conducting shell

In summary, the conversation discusses finding the potential at any distance from a spherical, charged, non-conducting shell with a given surface potential. The speaker is unsure how to relate the surface potential to the radius and whether solving the Laplace equation is necessary. They also mention using Legendre polynomials and the general solution of Laplace's equation in spherical coordinates.
  • #1
jerry222
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1
Homework Statement
Consider a spherical, charged, non-conducting shell of radius R. Given "surface potential", find potential at any distance.

I do realise there might be such a thing as a surface potential but how can i relate it to R, the distance? Am i supposed to solve the laplace equation with the given surface potential as a solution? I'm a bit stuck, appreciate any hint
Relevant Equations
$\Del V = 0$
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  • #2
jerry222 said:
Homework Statement:: Consider a spherical, charged, non-conducting shell of radius R. Given "surface potential", find potential at any distance.

I do realise there might be such a thing as a surface potential but how can i relate it to R, the distance? Am i supposed to solve the laplace equation with the given surface potential as a solution? I'm a bit stuck, appreciate any hint
Relevant Equations:: $\Del V = 0$

View attachment 323688
Have you tried part (b) first?
From the answer to that you should be able to get the answer to (a) if the integral is not too nasty.
 
  • #3
jerry222 said:
Am i supposed to solve the laplace equation with the given surface potential as a solution?
Yes. My hint would be to notice that the potential on the surface of the sphere, that you are given, can be expressed as the sum of just a few Legendre polynomials with certain coefficients. Then compare to the general solution of Laplace's equation in spherical coordinates for problems with azimuthal symmetry. Hopefully, you're familiar with equation (14) here.
 
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FAQ: Electrodynamics - finding potential of a non conducting shell

What is the electric potential inside a non-conducting spherical shell?

Inside a non-conducting spherical shell, the electric potential is constant and equal to the potential on the surface of the shell. This is because the electric field inside a non-conducting shell is zero, leading to no change in potential within the shell.

How do you calculate the potential outside a non-conducting spherical shell?

Outside a non-conducting spherical shell, the potential can be calculated using the formula for the potential of a point charge. If the shell has a total charge \(Q\) and radius \(R\), the potential at a distance \(r\) from the center (where \(r > R\)) is given by \(V = \frac{1}{4\pi\epsilon_0} \frac{Q}{r}\).

Does the charge distribution on a non-conducting shell affect the potential inside the shell?

No, the charge distribution on a non-conducting shell does not affect the potential inside the shell. The potential inside a non-conducting shell remains constant regardless of how the charge is distributed on the surface of the shell.

What boundary conditions are used to find the potential of a non-conducting shell?

The boundary conditions used are: (1) The potential must be continuous across the boundary of the shell, and (2) The electric field just outside the shell is determined by the surface charge density. These conditions ensure that the potential is correctly matched at the shell's surface.

How does the thickness of a non-conducting shell affect the electric potential?

The thickness of a non-conducting shell does not affect the electric potential inside or outside the shell. The potential inside the shell remains constant, and outside the shell, the potential depends only on the total charge and the distance from the center, not on the shell's thickness.

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