Consider a conducting spherical shell with an inner radius a and outer radius c. Let the Space between two surfaces be filled with two different dielectric materials so that the dielectric constant is k1 between a and b, and k2 between b and c, as shown in the figure. Assume the dielectric constants k1 = k2 = 2. The capacitance of the system is
1
\(\frac{{4\pi {\varepsilon _o}abc}}{{\left( {c - a} \right)}}\)
2
\(\frac{{4\pi {\varepsilon _o}ac}}{{\left( {c - a} \right)}}\)
3
\(\frac{{8\pi {\varepsilon _o}abc}}{{\left( {c - a} \right)}}\)
4
\(\frac{{8\pi {\varepsilon _o}ac}}{{\left( {c - a} \right)}}\)