(a) Find the capacitance of spherical capacitor having concentric shells of radii a `a` and `b (bgta)`. The space between the shells is completely filled by a dielectric of constant `k`.
(b) Find the capacitance if dielectric is filled upto an intermediate radius `c(a lt c lt b)` between the shells.

Answer

`C=4piepsilon_(0)k((ab)/(b-a))`; (b) ` (k abc)/(ka(b-c)+b(c-a))`