# Insulating spherical shell prob!

1. Oct 24, 2005

### hotmail590

A small, insulating, spherical shell with inner radius a and outer radius b is concentric with a larger insulating spherical shell with inner radius c and outer radius d. The inner shell has total charge +q distributed uniformly over its volume, and the outer shell has charge -q distributed uniformly over its volume.

How would i calculate the magnitude of the electric field for a < radius < b?

Would this forumla be correct?

q/(4*pi*Epsilon 0*(b-a)^2)

2. Oct 25, 2005

### Tide

Why would you expect the electric field to be constant in the intermediate region?