1 April 2014
1, (30 pts) A 50 D lossless transmission line is to be matched to an antenna load with
ZLOAD = 60 - j50 Q using a shorted stub inserted in parallel with the transmission line as
shown below. To receive any credit, a Smith chart must be used to solve this problem.
Notate the Smith chart with all stop and start points and label all line lengths on the Smith
chart and on the diagram below for full credit.
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1 April 2014
2. (30 pts) Use Coulomb's Law to find the electric field intensity, E at point (0,0,2m)
given charges located in free space at (lm,0,0), (05lm,0), (-lm,0,0) and (0,-lm,0). The
charge at each location is 5nC.
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1 April 2014
3. (30 pts) A sphere of radius 3m centered at the origin has a charge density of
pv = 2R fjC I m3. Using Gauss's law find the electric flux density, D, at a position 6m
away from the origin.
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1 April 2014
Short Problems and Questions
(1) (15pts) Given a ring in the x-y plane centered at the origin with charge pt = 4
and radius a, find the electric potential at point (0, 0, z).
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(2) (5pts) What is the current density , / , for a perfect dielectric? Why?
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(3) (5 pts) What does electron mobility, jue, describe?
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1 April 2014
(5) (5 pts) Why are the electric field and the magnetic field as described by Maxwell's
equations decoupled under static conditions?
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(6) (5 pts) Write the equation that is the basis for using KVL in EE221.
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