Question

Why must electrostatic field be normal to the surface at every point of a charged conductor ?

Please help:)

Answer 1

@experimentX @Callisto @Yahoo! Please help:)

Answer 2

Electric Fields are Perpendicular to Charged Surfaces

A second characteristic of conductors at electrostatic equilibrium is that the electric field upon the surface of the conductor is directed entirely perpendicular to the surface. There cannot be a component of electric field (or electric force) that is parallel to the surface. If the conducting object is spherical, then this means that the perpendicular electric field vectors are aligned with the center of the sphere. If the object is irregularly shaped, then the electric field vector at any location is perpendicular to a tangent line drawn to the surface at that location.

Understanding why this characteristic is true demands an understanding of vectors, force and motion. The motion of electrons, like any physical object, is governed by Newton's laws. One outcome of Newton's laws was that unbalanced forces cause objects to accelerate in the direction of the unbalanced force and a balance of forces causes objects to remain at equilibrium. This truth provides the foundation for the rationale behind why electric fields must be directed perpendicular to the surface of conducting objects. If there were a component of electric field directed parallel to the surface, then the excess charge on the surface would be forced into accelerated motion by this component. If a charge is set into motion, then the object upon which it is on is not 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. Certainly a conducting object that has recently acquired an excess charge has a component of electric field (and electric force) parallel to the surface; it is this component that acts upon the newly acquired excess charge to distribute the excess charge over the surface and establish electrostatic equilibrium. But once reached, there is no longer any parallel component of electric field and no longer any motion of excess charge.


http://www.physicsclassroom.com/class/estatics/u8l4d.cfm

Answer 3

Isn't there any easy way?
this blog has some hard language for me:(

Please help:)

Answer 4

will u make me understand this @Yahoo! @experimentX :)

Answer 5

electric lines of force never cross each other ... if you zoom ... not matter how curved the surface is .... it always looks straight. and you know how electric lines of force ... electric flux is for a .... plane sheet of conductor.

Answer 6

isn't there a good& easy answer becoz
this came in my exam:)
Please post that:)

Answer 7

here is a flat conductorwe want to know the field on a test charge q near the surface....
each portion of the conductor contributes some electric field element