Chapter 24 Electric Potential

1. Chapter 24 Electric Potential In this chapter we will define the electric potential( symbol V ) associated with the electric force and accomplish the following tasks: Calculate V if we know the corresponding electric field. Calculate the electric field if we know the corresponding potential V. Determine the potential V generated by a point charge. Determine the potential V generated by a discrete charge distribution. Determine the potential V generated by a continuous charge distribution. Determine the electric potential energy U of a system of charges. Define the notion of an equipotential surface. Explore the geometric relationship between equipotential surfaces and electric field lines. Explore the potential of a charged isolated conductor. (24-1)

2. Checkpoint 1: • In the figure, a proton moves from point i to point f in a uniform electric field directed as shown. • Does the electric field do positive or negative work on the proton? • Does the electric potential energy of the proton increase or decrease? c) Does the force do positive or negative work? d) Does the proton move to a point of higher or lower potential?

7. Electric potential is a scalar property associated with an electric field, regardless of whether a charged object has been placed in that field; it is measured in joules per coulomb or volts. V Electric potential energy is an energy of a charged object in an external electric filed ( or more precisely, an energy of the system consisting of the object and the external electric field); it is measured in joules. U

8. (24-10)

9. V  B A S q S V (24-11)

10. Checkpoint 3: • The figure here shows a family or parallel equi potential surfaces ( in cross section) and five paths along which we shall move an electron from one surface to another. • What is the direction of the electric field associated with the surfaces? • For each path, is the work we do positive, negative, or zero? • Rank the paths according to the work we do, Greatest first.

11. q1 r1 q2 r2 P r3 q3 (24-5)

14. Checkpoint 4: The figure here shows three arrangements of two protons, Rank the arrangements according to the net electric potential produced at point P by the protons, Greatest First

15. A B V+dV V (24-14)

17. q2 y r12 r23 q1 r13 q3 x O (24-15)

22. (24-19)

23. R (24-20)

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