Why must electrostatic field at the surface of a charged conductor be normal to the surface at every point? Give reason.
Answers
Explanation:
If the electrostatic field lines are not perpendicular to the surface of the conductor, there will be a tangential component of the electric field. If that is the case, it would create a potential difference and would accelerate the free electrons resulting in current. The only way a conductor can stay at a constant potential throughout or be an equipotential surface, is if the electric field lines are perpendicular to all elemental surfaces of the conductor.
When an additional charge is deposited on the conductor or placed in its vicinity, the free electrons re-arrange themselves in a finite but very short time, until the potential is the same throughout.
As, electric field inside the conductor is always zero .the electric lines of force exert lateral pressure on each other which leads to repulsion between like charge this in order to stabilize spacing, the electric field lines are normal to the surface