A long coaxial cable consists of an inner solid cylinder, radius a, and an outer thin coaxial cylindrical shell, radius b. The outer shell carries a uniform surface charge density σ.
Find the uniform volume charge density ρ that the inner cylinder must have in order that the whole cable (inner + outer) is neutral.
Acylinder = 2πbl
Vcylinder = πa2l
ρ = Q/V
∇∙E = ρ/ϵ0
Qenc = ∫Vρdτ
The Attempt at a Solution
I feel like I have all the relevant equations, yet, I still do not know how to start this. Any hints? Very much appreciated.