EES 612 Midterm: EES 612-Midterm-F2013-Solution
31 Jan 2019
School
Department
Course
Professor
So\w*ron & U"rkiy^g;
Ryerson University
Department of Electrical and Computer Engineering
EE5612 (Electric Machines and Actuators)
i Midterm Examination (F2013) ,
i October 20X3 '
Duration: 120 minutes
Examiners: Profs. A. Yazdani and S. Karim
Name:
Student No:.......
[Print Last Name] [Print First Name]
Section No:........
NOTES
1. This is a closed-book examination. Only basic scientific calculators are permitted as the
aid.
2. The examination paper is comprised of FOUR QUESTIONS, each qtestion worth as
indicated by the table below. The entire examination is worth 200 marks.
Question #Maximum Mark Mark Earned
150
250
35U
450
Total 200
J. Answer all questions in the booklet, within the blank spaces provided underneath each
question. Use the reverse side ifneeded.
4, No questions to be asked durinq the examination. If in doubt about any question,
clearly state your assumptions in answering the question.
5. Part marks for an answer will only be granted if the correct methodology is clearly
shown.
d, The last page ofthis booklet has some useful formulas and equations.
7. You mav detach the formula sheet onlv, but you must return it with your name printed
on it, along with your written exam booklet.
Ql: Consider the magnetic system ofFig. 1 whose left-hand side leg has a N turn winding and
whose right-hand side leg has an air gap of g. The magnetic material of the core has of a
constant relative permeability of ,u". The flux path has a mean length of /", which is
considerably larger than g. The cross-sectional area of the flux path is .4 throughout the
structure (including the air gap). Fringing and leakage of the flux may be ignored. provide
an expression for the inductance ofthe winding.
Fig. 1: magnetic system of Q1
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Page 2 of 12
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Page 4 of 12
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