The electric potential of 2 hollow concentric spherical shells

[Figigaly]

Homework Statement

Consider two concentric conductive hollow spherical shells. The inner shell has radius R1 and holds the charge +q. The outer shell has charge R2 and holds charge -q. Determine an expression for the potential difference between the shells.

Homework Equations

V = q / (4 pi ε₀ r) when r greater or equal to the radius of the shell

V = q / (4 pi ε₀ R) when r is less than the radius (R) of the shell

The Attempt at a Solution

I said due to fact that electric potential has superposition principle. The total electric potential between the shells:
therefore: V = q / (4 pi ε₀) (1/r - 1/R2)
I am unsure if this is true or not any help would be appreciated, Thanks

 

[ideasrule]

Yup, looks right to me.