Question

Three concentric spherical conductors are shown in figure. Determine the equivalent capacitance of the system between $B$ and $C$.

Answer 1

Equivalent circuit is shown in diagram

Also

$C_1=\frac{4\pi {\in }_{0}ab}{b-a}$

$C_2=4\pi {\in }_{0}c$

$C_3=\frac{4\pi {\in }_{0}bc}{c-b}$

$C_{eq}=C_3+\frac{C_1{C}_2}{C_1+C_2}$

$C_{eq}=\frac{4\pi {\in }_{0}bc}{c-b}+\frac{4\pi {\in }_{0}abc}{ab+c(b-a)}$