Eight point charge of charge `q` each are placed on the eight corners of a cube of side a. A solid neutral metallic sphere of radius ` a//3` is placed with its centre at the centre of the cube . As a result charges are induced on the sphere , which form certain pattern on its surface . What is the potential at the center of the sphere .

Options

A. `(-12)/sqrt3(Kq)/a`
B. `(18)/sqrt4(Kq)/a`
C. `-(8)/sqrt2(Kq)/a`
D. `(16)/sqrt3(Kq)/a`

Answer

D