A spherical conductor of radius 12 cm has a charge of `1.6xx10^(-7)C` distributed uniformly on its surface. What is the electric field (a) inside the sphere (b) just outside the sphere (c ) at a point 18 cm from the center of the sphere ?

Explanation

Here, `r = 12 cm = 12xx10^(-2) m, q = 1.6xx10^(-7) C`.
(a) Inside the sphere, `E = 0`
(b) Just outside the sphere, (say on the surface of the surface)
`E = (q)/(4pi in_(0) r^(2)) = 9xx10^(9)xx (1.6xx10^(-7))/((12xx10^(-2))^(2)) = 10^(5) N//C`
(c ) At `r' = 18 cm = 18xx10^(-2) m, E = (q)/(4pi in_(0) r'^(2)) = (9xx10^(9)xx1.6xx10^(-7))/((18xx10^(-2))^(2)) = 4.4xx10^(4) N//C`