Physics 110a Fall 2004 Prof. Orenstein
Quiz #1: Two questions, each has three parts. Each part is worth 20 points, making
a total possible score of 120 points.
Problem 1
Consider a point charge +q that is suspended above the apex of a wedge-shaped
conductor, as shown below. (The star in the drawing is not a charge. It denotes a point in
space referred to in last part of this problem).
a) Make a sketch of the electric field lines, with enough detail to illustrate the main
features of the field.
b) Is the point charge (i) attracted to apex of the wedge, (ii) repelled, or (iii) neither.
c) Consider the work required to bring another charge q from infinity to the point in
space indicated by the star, with the other charge and the conductor held fixed. Is
this amount of work (i) greater, (ii) lesser, or (iii) the same as the work required if
the conductor were not there [you need not calculate the work, just argue on
prinicple].
q
