Thank Tou very much for your answer ! That was i was thinking about.vanhees71 said:I think you talk about electrostatics. Then indeed the electric field has a potential and the tangent component of it must vanish, because by definition a conductor consists of a material containing charges (usually electrons, at least for metals) that can move quasi freely within the material. This means that if there where a component of the electric field tangential to the surface of a conductor these conduction electrons would be set into motion due to the electric force in that direction, and you'd have an electric current flowing, but then you are out of the realm of electrostatics. The normal component of the electric field can be non-zero, because the conduction electrons are bound to the conductor. Of course, if you make the external electric field too strong you can free those electrons overcoming the binding energy, but then you also leave the realm of electrostatics, because again an electric current would flow.
The tangential part of the potential electric field is the component of the electric field that is parallel to the surface of an object. It is also known as the parallel component.
The tangential part of the potential electric field can be calculated using the formula: E_t = E * cos(theta), where E is the total electric field and theta is the angle between the electric field and the surface of the object.
The tangential part of the potential electric field is important in understanding the behavior of electric fields near surfaces. It helps determine the direction and strength of the electric field at a specific point on the surface.
The tangential part of the potential electric field influences the movement of charged particles by exerting a force on them parallel to the surface of the object. This force can either attract or repel the particles depending on their charge.
Yes, the tangential part of the potential electric field can be negative. This indicates that the electric field is pointing in the opposite direction of the surface at that point. It can also be positive, indicating that the electric field is pointing in the same direction as the surface.