how can I find the potential created by spherical capacitor with dielectric material

Question

If we have a spherical capacitor with inner radius or r1 and outer radius of r2, with charges (+/-)q on them and there is a dielectric material (with constant e) in between them with.

What kind of a potential would this create outside the entire capacitor? in the region with the dielectric? and inside the entire thing?

Answer 1

This is quite simple as this is a standard equation for the capacitance. You will have

$$C=\epsilon C_0$$

being $C_0$ the capacitance in vacuum. For a full set of formulas in different geometrical configurations see here.

Answer 2

You can write down these fields directly without calculating anything because the field of a charged sphere is the same as that of a point charge outside the sphere and zero inside the sphere.

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/potsph.html