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Why is no work done when a charge moves along an equipotential surface?
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electricity
Explanation of static electricity and its manifestations in everyday life.
No work is done when a charge moves along an equipotential surface because the electric potential is constant at every point on that surface.1
By definition, the work required to move a charge between two points is equal to the difference in potential energy between those points. Since an equipotential surface consists of points that all share the same potential value, the potential difference between any two locations on the surface is zero.21
Furthermore, in a static electric field, the field lines are always perpendicular to equipotential surfaces. Because the motion of a charge along the surface is always perpendicular to the direction of the electric force, no work is performed by the field during this movement.31