Day 17: Equipotential Surfaces Lines of equal potential Equipotential Surfaces Justification for Perpendicularity to the Electric Field Mapping of Equipotential Surfaces

Equipotential Lines A line in which all points are at the same voltage, is called an equipotential line. Equipotential Lines are perpendicular to the electric field

Equipotential Surfaces A surface in which all points are at the same voltage is called an equipotential surface An equipotential surface must be perpendicular to the electric field

Justification of Perpendicularity to the Electric Field On a surface where V is constant, ΔV = 0, so either E = 0, or dl = 0, or cosθ = 0 (where cosθ is the angle between E & dl). For cosθ = 0, θ = 90°, On a surface of a conductor of uniform charge, the entire surface is an equipotential surface, otherwise free electrons on the surface would move through the potential difference