PHYS 241
Notes for Test 2
Chapter 24 Electric Potential
Review and Summary is on p. 645.
Know the definitions of change in electric potential energy (U) and electric potential energy (U) as
given in Eqs. 24-1 and 24-2 in the first section of the Review and Summary.
Know the definitions of potential difference (V) and potential (V) as given in Eqs. 24-7 and 24-8 in the
second section of the Review and Summary.
Know the relationships between potential and electric potential energy as given in Eqs. 24-5 and 24-6 in
the second section of the Review and Summary.
You should know the definition of an Equipotential Surface.
You should know Eq. 24-26 for the potential due to a point charge and Eq. 24-27 for the potential due to
a collection of point charges.
You should know how to use Eqs. 24-41 to find the components of the electric field given the potential
V(x, y, z).
You should know how to find the electric potential energy of a system of point charges. (See Sample
Problem 24-6 on p. 642 and homework problem 41 on p. 650.)
You should be able to prove the following statement:
An excess charge placed on a conductor distributes itself so that the entire conductor, including interior
points, is at a uniform potential once electrostatic equilibrium is attained.
Chapter 25 Capacitance
Review and Summary is on p. 675.
You should know Equations 25-1, 25-19 and 25-20.
You should know how to find the equivalent capacitance of a capacitance network and find the charge
on and voltage across any of the capacitors in the network.
Know that when a dielectric fills the space between the plates of a capacitor the capacitance becomes
C, where C is the air capacitance and is the dielectric constant of the dielectric.
You should know the definition of the dielectric strength of a dielectric.
Continued on the other side
