Home Work Set # 9, Physics 217, Due: November 14,
2001
Problem 1
An electric dipole
,
pointing in the
y direction, is placed midway between two large
conducting plates, as shown in Figure 1. Each plate makes a small angle
θ with respect to the
x axis, and they are maintained at
potentials ±
V. What is the direction of the net force on
?
Explain!
Figure
1. Problem 1.
Problem 2
A point charge q is embedded at the center of a sphere of linear
dielectric material (with susceptibility χe and radius
R).
a) Find the electric field, the polarization and the bound
charge.
b) What is the total bound charge on the surface?
c) Where is the
compensating negative bound charge located?
Problem 3
At the interface between one linear dielectric and another linear
dielectric the electric field lines bend (see Figure 2). Show that
tanθ2/tanθ1 =
ε2/ε1, assuming that there is no
free charge at the boundary.
Figure
2. Problem 3.
Problem 4
a) Find the force on a square loop placed as shown in Figure 3a, near an
infinite straight wire. Both the loop and the wire carry a steady current
I.
b) Find the force on a triangular loop placed as shown in Figure
3b, near an infinite straight wire. Both the loop and the wire carry a steady
current I.
Figure
3. Problem 4.
Problem 5
Suppose the magnetic field in some region has the form
where k is some constant. Find the force on a square loop of side
s, lying in the yz plane, centered at the origin, which carries a
current I.
