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Physics 503
Final Exam 2012
Problem 1 A long thin wire carrying a current I lies parallel to and at distance d from semi-innite slab of iron with
permeability
0 . Determine the magnitude and direction of the force per unit length of the wire.
Solution
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3.3) We would like to nd the potential created by a thin, at conducting circular disc of radius R located in the
p
x y plane, mantained at xed potential V . The charge density on a disc is proportional to 1/ R2 r2 , where r is
the dis
1
Physics 503
Midterm Exam 2012
Problem 1 Two equal charges +Q are separated by a distance 2d. A grounded conducting sphere is placed midway between
them.
a) What is the electrostatic potential of the system. Express it in terms of r and , where the z axi
1
Physics 503
Midterm Exam 2012
Problem 1 Two equal charges +Q are separated by a distance 2d. A grounded conducting sphere is placed midway between
them.
a) What is the electrostatic potential of the system. Express it in terms of r and , where the z axi
1
Physics 503
Final Exam 2012
Problem 1 A long thin wire carrying a current I lies parallel to and at distance d from semi-innite slab of iron with
permeability
0 . Determine the magnitude and direction of the force per unit length of the wire.
Problem 2
1
Physics 503
Midterm Exam 2011
Problem 1 Within a sphere of radius R there is a non-zero charge density,
R
sin2 .
r
(1)
(r )
4 0 |r r |
(2)
(r, , ) = 0
The sphere is surrounded by an innite vacuum.
a) Determine the total charge.
b) Determine the potentia