Problems from HRW Problem Supplement #1 (6th edition)
Chapter 24

55.  The figure for this problem is Fig. 24-5.  An
     electric field given by E = 4i - 3(y^2 + 2)j
     pierces the Gaussian cube shown in the figure.
     (E is in N/C and y is in m.)  What is the 
     electric flux through (a) the top face, (b) the
     bottom face, (c) the left face, and (d) the back
     face.  (e) What is the net electric flux through
     the cube?  (f) What net charge is enclosed by 
     the Gaussian cube?

66.  A thin, metallic, spherical shell of radius a
     has a charge Qa.  Concentric with it is another
     thin, metallic, spherical shell of radius b
     (where b > a) and charge Qb.  Find the electric
     field at points a distance r from the common
     center, where (a) r < a, (b) a < r < b, and
     (c) r > b.  (d) Determine how the charges are
     distributed on the inner and outer surfaces of
     the shells (give the surface charge densities).

Problems from Fishbane, Gasiorowicz, and Thornton 
(2nd edition) Chapter 24

38.  Two large, thin, metallic plates are placed
     parallel to each other, separated by 15 cm.  The
     top plate carries a uniform charge density of
     24 microC/m^2, while the bottom plate carries a
     uniform charge density of -38 microC/m^2.  What 
     is the electric field (magnitude and direction) 
     (a) halfway between the plates? (b) above the 
     two plates?  (c) below the two plates?  
     (d)  What are the surface charge densities on 
     the top and bottom surfaces of both plates?

45.  A metal sphere of radius a is surrounded by a
     metal shell of inner radius b and outer radius R.
     The flux through a spherical Gaussian surface
     located between a and b is Q/epsilon0, and the
     flux through a spherical Gaussian surface just
     outside radius R is 2Q/epsilon0.  (a) What are 
     the total charges on the inner sphere and on the 
     shell?  (b) Where are the charges located, and 
     (c) what are the charge densities?