plz clear this concept , i am little confused , brief me about the topic Conductors in Electric Field;

Conductors in Electric Fields

• A large number of electrons in a conductor are free to move. 
• If the electric field inside the conductor would not be exactly zero the free electrons would continue to move and the charge distribution would not be in static equilibrium.
• The electric field on the surface of the conductor is perpendicular to its surface.

The strength of the electric field on the surface of a conductor can be found by applying Gauss' law. The electric flux through the surface shown in Figure is given by

where A is the area of the top of the surface shown in Figure The flux through the bottom of the surface shown in Figure is zero since the electric field inside a conductor is equal to zero. Note that eq. is only valid close to the conductor where the electric field is perpendicular to the surface. The charge enclosed by the surface shown in Figure is equal to

 
                 Electric Field Of Conductor
                                 

where [sigma] is the surface charge density of the conductor. is correct if the charge density [sigma] does not vary significantly over the area A (this condition can always be met by reducing the size of the surface being considered). Applying Gauss' law we obtain

Thus, the electric filed at the surface of the conductor is given by