Chapter 23 Electric Potential Electric potential energy(sec. 23.1) Electric potential (sec. 23.2) Calculating elec. potential(sec. 23.3) Equipotential surfaces(sec. 23.4) Potential gradient(sec. 23.5) C 2009 J. F. Becker

POSITIVE charge moving in an E field. (a) When a positive charge moves in the direction of an electric field, the field does positive work and the potential energy decreases. Work = q o E d

The charge q o moves along a straight line extending radially from charge q.

The work done on charge q o by the electric field produced by charge q depends only on the distances r a and r b.

Graphs of the potential energy U of two point charges q and q 0 versus their separation r.

The potential energy associated with a charge q o at point “a” depends on charges q 1, q 2, and q 3 and on their distances r 1, r 2, and r 3 from point “a.”

Calculating the electric potential by integrating E. dl for a single point charge. In both cases (positive or negative point charges), if you move in the direction of E, electric potential V decreases; if you move in the direction opposite E, V increases.

Electric field E and potential V at points inside and outside a positively charged spherical conductor.

All charges in the ring (Q) are the same distance a from point P on the ring axis. Find the potential V at point P on the axis of the ring.

Find the potential V at point P. Find the electric potential on the perpendicular bisector of a charged rod.

See Review C 2009 J. F. Becker