Educator

Electric Potential

• To move a particle with charge q in an electric field, from point A to point B, an external agent needs to do work; the amount of work done is equal to Ub –Ua, where Ub is the electric potential energy at A, and Ub is the electric potential energy at B.
• In a uniform electric field, the potential difference between 2 points separated by a vector d is the dot product E.d; if you move along the field lines, the potential drops.
• The electric potential of a point charge Q at a distance r is V = kQ/r.
• A surface perpendicular to the electric field lines is an equipotential surface.
• The potential energy of a system of 2 point charges Q and Q’ separated by a distance r, is U = kQQ’/r.