Electric Potential & Voltage

Map equipotential surfaces and understand work done by electric fields

Electric potential V at a point is the work done per unit positive charge to bring a test charge from infinity to that point. For a point charge, V = kq/r, and the field points in the direction of decreasing potential: E = −ΔV/Δx. Equipotential lines connect points of equal potential; they are always perpendicular to electric field lines. No work is done moving a charge along an equipotential surface.