Spherical Charge Distribution

[raab32]

I'm looking over some physics material right now and had a conceptual question about spherical charge distribution just to clarify my understanding. So the basic idea is that a uniform sphere will have uniform distribution of its charge throughout its surface. In this way, Couloumb's law can be applied to finding electrostatic interactions between the sphere and point charges on its surface.

Now my question is, how can the material of the sphere get factored in? If one were to compare two spheres with the same area, but one was a much better insulator than the other, would you expect different forces of attraction for a point charge located the same distance away?

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[loveoforganic]

I don't think so

 

[raab32]

Oh hmm... charge doesn't distribute uniformly in an insulator right? So I guess that plays a role...

 

[loveoforganic]

Part of your premise was that you had uniform spherical charge distribution...

 

[raab32]

Right yeah, I forgot to consider that distribution doesn't occur uniformly in an insulator. But even so, the situation in my q can be changed to comparing two conductors, one of them stronger than the other... does force of attraction differ? You say it doesn't... why is that? Sorry, just trying to get a grasp of the bigger conceptual picture.

 

[loveoforganic]

In what way would the conductivity of the material affect anything? The only thing I could maybe see mattering is dielectric constant.

 

[wanderer]

I'm looking over some physics material right now and had a conceptual question about spherical charge distribution just to clarify my understanding. So the basic idea is that a uniform sphere will have uniform distribution of its charge throughout its surface. In this way, Couloumb's law can be applied to finding electrostatic interactions between the sphere and point charges on its surface.

Now my question is, how can the material of the sphere get factored in? If one were to compare two spheres with the same area, but one was a much better insulator than the other, would you expect different forces of attraction for a point charge located the same distance away?

Although there is different charge distribution when comparing a conductor and an insulator the electrostatic forces exerted by these two on a charged particle at some distance past the shell is the same. The only difference is for the force on some particle within the physical spheres.
This is what Gauss's Law tells us.