electric field, concentric shells

[Chronos000]

1. The problem statement, all variables and given/known data

The question I'm struggling with is to find the electric field at radius r from the centre of two conducting spherical shells of radius a and b (b>a), and with charge +Q and -Q.

Specifically I am not sure if there is no electric field at r>b as if you use gauss' law, the total charge within the gaussian surface is 0.

[G01]

Specifically I am not sure if there is no electric field at r>b as if you use gauss' law, the total charge within the gaussian surface is 0.

This is correct. The total enclosed charge is 0, so the flux through any Gaussian surface with r>b will be 0.

[Chronos000]

thanks for confirming