Question

Consider a sphere of radius r having charge q uniformly distributed inside it

Answer 1

We are knowing that for non conducting sphere of Radius = R:Einside= kqr/R3 where k = 9*109q = charge of spherer= distance measured from centre to the distance "r" that is smaller than RE surface = kq/R2equating Einside=E surface  kqr/R3=1/2(kq/R2)r= R/2From the surface = R - R/2 = R/2