Electrostatics: Field due to chargespherical shells

I need help with this problem:

A small conducting spherical shell with inner radius a and outer radius b is concentric with a larger conducting spherical shell with inner radius c and outer radius d. The inner shell has a total charge of +2q, and the outer shell has a total charge of +4q.

a) Calculate the electric field (magnitude and direction) in terms of q and the distance r
from the common centre of the two shells for i) r < a; ii) a < r < b; iii) b < r < c; iv) c < r < d, and v) r > d. Show your results as a graph.

b) What is the charge on the inner and outer surfaces of both the small and large shells?

Thanks

Solution Summary

Two charge spherical conducting shells of radii a, b, c, d are concentric and charged with 2q and 4q. Field at every point of space is calculated. The field-position graph is also plotted.