Find the capacitance of a system of two identical metal balls of radius a if the distance between their centres is equal to `b`, with `b gt gt a`. The system is located in a uniform dielectric with permittivity `K`.

Options

A. `pi in_(0) Ka`
B. `pi in_(0) Ka`
C. `2 pi in_(0) Ka`
D. `2//3 pi in_(0) Ka`

Answer

C

Explanation

`V_(1)-V_(2)=2V =2 underset(a) overset(b-a) int E dr ,C=(q)/(V_(1)-V_(2))`.