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 ?

(a) radius of the of the spherical conductor, r=12 cm =0.12 m <br> charge is uniformly distributed over the conductor, `q=1.6xx10^(-7) C` <br> electric field inside a spherical conductor is zero. This is because if there is field inside the conductors , then charges will move to neutralize it. <br> (b) electric field E just outside the conductor is given by the relation, <br> `E=q/(4piin_(0)r^(2))` <br> where, `in_(0)` =permitivity of free space <br> `1/(4piin_(0))=9xx10^(9) Nm^(2)C^(-2)` <br> `:. E=(1.6xx10^(-7)xx9xx10^(-9))/((0.12)^(2))` <br> `=10^(5)NC^(-1)` <br> Therefore, the electric field just outside the sphere is `10^(5) NC^(-1)` <br> (C) electric field at a point 18 m from the centre of the sphere `=E_(1)` <br> distance of the point from the centre, d=18 cm =0.18 m <br> `E_(1)=q/(4pi in_(0)d^(2))` <br> `=(9xx10^(9)xx1.6xx10^(-7))/((18xx10^(-2))^(2))` <br> `=4.4 xx10^(4) N//C` <br> Therefore, the electric field at a point 18 cm from the centre of the sphere is <br> `4.4xx10^(4) N//C`