A spherical conductor of radius 0.12 m has a charge of `1.6xx10^(-7)`C distributed uniformly on its surface, what is the electric potential?
(a) inside the sphere?
(b) Just outisde the sphere?
(c) At a point 0.18 m from the centre of the sphere?

Explanation

Given r=0.12m, q=`1.6xx10^(-7)C`
(a) Electric field intensity at any point inside the sphere is zero
`(because Q_("inside")=0)`
but, electric potential at a point inside the charged sphere is the same as the potential on the surface.

(b) Electric potential on the surface or just outside the surface
`V=((1)/(4piepsi_(0)))((Q)/(R)),` 'R' is the radius of the sphere.
Thus, `V=(9xx10^(9)xx1.6xx10^(-7))/(0.12)=1.2xx10^(4)V`
(c) Electric potential at a distance 0.18 m from the centre of the sphere.
`V=(9xx10^(9)xx1.6xx10^(-7))/(0.18)=8.0xx10^(3)V`