1. The problem statement, all variables and given/known data Why are both these problems identical? In both cases, c>b>a. Q1 Three concentric conducting shells A, B and C of radii a, b and c are arranged as shown. A dielectric of dielectric constant K is filled between A and B. Find the capacitance between A and C. Q2 A spherical capacitor is made of two conducting spherical shells of radii a and c. The space between the shells is filled with a dielectric of dielectric constant K unto a radius b as shown. Find the capacitance of the system. 2. Relevant equations 3. The attempt at a solution Both have answers (4πεo.Kabc)/(Ka(c-b)+c(b-a)) I know how to do the first one, but I don't understand why both have the same answer, ie. why the capacitance of the system is equal to the capacitance between A and C.