1. The problem statement, all variables and given/known data An infinitely long solid conducting cylindrical shell of radius a = 3.1 cm and negligible thickness is positioned with its symmetry axis along the z-axis as shown. The shell is charged, having a linear charge density λinner = -0.49 μC/m. Concentric with the shell is another cylindrical conducting shell of inner radius b = 15.6 cm, and outer radius c = 18.6 cm. This conducting shell has a linear charge density λ outer = 0.49μC/m. 1.What is V(c) – V(a), the potential difference between the the two cylindrical shells? 2. What is C, the capacitance of a one meter length of this system of conductors? 2. Relevant equations E = Q/(2πr^2εo) Q = λSa where Sa = 2πr^2 3. The attempt at a solution For the first question, I did the integral ∫E.dA = q/εo E(2πr^2) = q/εo E = Q/(2πr^2εo) Then I integrated that between upper bound a and lower bound b to get: ΔV = -Q/(2πεo) ∫dr/(r^2) = Q/(2πεo)*(1/r) or Q/(2πεo)*((1/a)-(1/b)) However, my answer was incorrect. I am just learning integrals, so I'm not sure if I set up the integral incorrectly. The Q I used is the inner charge, calculated with Q = λ*(2πr^2), which, with values, is Q = (-0.49 μC/m)*(2π*0.031^2). I've done a couple of problems with concentric insulators and conductors inside, but the whole idea is very confusing for me and I don't really understand concepts. I find myself just plugging numbers into random equations to find answers. For the second question, would I just take the total Q and divide that by the potential difference? Any help is appreciated. Thanks!