The radii of the two concentric conductive spheres are r1 and r2>r1. The resistivity of the material between the spheres is p. If the total current I from the inner sphere to the outer sphere is I,...

The radii of the two concentric conductive spheres are r1 and r2>r1. The resistivity of the material between the spheres is p.

If the total current I from the inner sphere to the outer sphere is I, find the electric field E at the point r (vectoral position) in the material between them.

Give your answer in terms of (r1, r2, r, p, I).