A spherical capacitor is made of two conducting spherical shells of radii a and b. The space between the shells is filled with a dielectric of dielectric constant K up to a radius c as shown in figure. Calculate the capacitance.

Question

Philoid · Accepted Answer

Lets re-draw the diagram-

We know, capacitance for a spherical capacitance c is given by-

C =

Where,

C: Capacitance

r_i: inner radius

r_o: outer radius

k: relative permittivity

∈: permittivity of space

Capacitance between c and a-

Similarly, between b and c

From fig, we can see that the two capacitors are connected in series, hence the net capacitance is given by-