The electric field at the surface of a conductor is A parall

The electric field at the surface of a conductor is A) parallel to the surface. C) never zero. B) always zero. D) perpendicular to the surface

Solution

The electric field at the surface of a conductor is always perpendicular to the surface. Hence the option is D.

If it exists a component of electric field parallel to the surface, then the excess charge on the surface accelerates by this component. If a charge accelerattes, then the surface on which charge exists will not be in a state of electrostatic equilibrium. Therefore, the electric field must be entirely perpendicular to the conducting surface for objects that are at electrostatic equilibrium.