EEE-360 Energy Systems and Power Electronics Midterm Exam 1|Questions
and Answers Latest Updated 2026/2027 (Graded A+)- ASU
Closed book. You only can use one sheet (both side) of hand written notes and your calculator. No book, no
computer use is permitted. All questions are compulsory. There is only one Correct Answer.
Once you have submitted the quiz, follow directions and scan your work and upload to Canvas using the
link that says 'upload your midterm_1_ work'. You will have 10 minutes beyond the 90 minutes to scan and
upload your work. In order that you are able to insure your file is correctly uploaded, start your exam no
later than around 10:30pm Tuesday night.
(Q1 Canvas) Problem 1: If the load impedance is 60+𝑗60 Ω, the power factor of the load is: 75pts
A. ∠−45°
Z=60.sqrt(2) invtan(60/60)= 60.sqrt(2) at 45 deg
B 1.0
Pf = cos 45 deg = 0.707
C. 0.7071
D. None of the above
Correct Answer: C
(Q2 Canvas) Problem 10: For a well-designed power system, which of the following is most desirable? 75pts
A. Large voltage regulation, and High Power Factor
B. Small voltage regulation, and High Power Factor
C. Large voltage regulation, and Low Power Factor
D. Small voltage regulation, and Low Power Factor
Correct Answer: B
(Q3 Canvas) Problem 11: With regards to the open circuit test on real power transformers, which of the following
sentence is most appropriate? 75pts
A. In an open circuit test, the low voltage side is open circuited and we use the test results to
calculate the parameters of the magnetizing branch
B. In an open circuit test, the high voltage side is open circuited and we use the test results to
calculate the parameters of the equivalent series branch
C. In an open circuit test, the low voltage side is short circuited and we use the test results to
calculate the parameters of the equivalent series branch
1
, D. In an open circuit test, the high voltage side is open circuited and we use the test results to
calculate the parameters of the magnetizing branch
Correct Answer: D
(Q4 Canvas) Problem 12: For a three-phase system, in which the generator is wye and the load is delta, which
of the following statement is true? 100pts
A. For the delta connected load, the magnitude of the line current is √3 the magnitude of the
delta load (phase) current
B. For the delta connected load, the line current leads the delta load (phase) current by 30°
C. For the wye connected generator, the magnitude of the line-to-neutral (phase) voltage is √3
the magnitude of the line-to-line voltage
D. For the wye connected generator, the line-to-neutral (phase) voltage leads the line-to-line
voltage by 30°
Correct Answer: A
(Q5 Canvas) Problem 13: With regards to impedance transfer in a transformer, if 𝑇=𝑁𝑝/𝑁𝑠 denotes the turns
ratio, then which of the following statement is correct? 100pts
A. When the secondary impedance is moved to the primary side, the secondary impedance is
multiplied by 𝑇
B. When the secondary impedance is moved to the primary side, the secondary impedance is
multiplied by 𝑇^2
C. When the secondary impedance is moved to the primary side, the secondary impedance is
divided by 𝑇
D. When the secondary impedance is moved to the primary side, the secondary impedance is
divided by 𝑇^2
Correct Answer: B
(Q6 Canvas) Problem 14: For a wye-delta three phase transformer, which of the following is true? 100pts
Note: Letters in upper-case denote the primary side, while the letters in lower case denote the
secondary side.
A. 𝑽𝐴B is in phase with 𝑽𝑎𝑛 and 𝑽𝐴B leads 𝑽𝑎b by 30°
B. 𝑽𝐴B is in phase with 𝑽𝑎𝑛 and 𝑽𝐴B lags 𝑽𝑎b by 30°
C. 𝑽𝐴N is in phase with 𝑽𝑎b and 𝑽𝐴B leads 𝑽𝑎b by 30°
D. 𝑽𝐴N is in phase with 𝑽𝑎b and 𝑽𝐴B lags 𝑽𝑎b by 30°
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and Answers Latest Updated 2026/2027 (Graded A+)- ASU
Closed book. You only can use one sheet (both side) of hand written notes and your calculator. No book, no
computer use is permitted. All questions are compulsory. There is only one Correct Answer.
Once you have submitted the quiz, follow directions and scan your work and upload to Canvas using the
link that says 'upload your midterm_1_ work'. You will have 10 minutes beyond the 90 minutes to scan and
upload your work. In order that you are able to insure your file is correctly uploaded, start your exam no
later than around 10:30pm Tuesday night.
(Q1 Canvas) Problem 1: If the load impedance is 60+𝑗60 Ω, the power factor of the load is: 75pts
A. ∠−45°
Z=60.sqrt(2) invtan(60/60)= 60.sqrt(2) at 45 deg
B 1.0
Pf = cos 45 deg = 0.707
C. 0.7071
D. None of the above
Correct Answer: C
(Q2 Canvas) Problem 10: For a well-designed power system, which of the following is most desirable? 75pts
A. Large voltage regulation, and High Power Factor
B. Small voltage regulation, and High Power Factor
C. Large voltage regulation, and Low Power Factor
D. Small voltage regulation, and Low Power Factor
Correct Answer: B
(Q3 Canvas) Problem 11: With regards to the open circuit test on real power transformers, which of the following
sentence is most appropriate? 75pts
A. In an open circuit test, the low voltage side is open circuited and we use the test results to
calculate the parameters of the magnetizing branch
B. In an open circuit test, the high voltage side is open circuited and we use the test results to
calculate the parameters of the equivalent series branch
C. In an open circuit test, the low voltage side is short circuited and we use the test results to
calculate the parameters of the equivalent series branch
1
, D. In an open circuit test, the high voltage side is open circuited and we use the test results to
calculate the parameters of the magnetizing branch
Correct Answer: D
(Q4 Canvas) Problem 12: For a three-phase system, in which the generator is wye and the load is delta, which
of the following statement is true? 100pts
A. For the delta connected load, the magnitude of the line current is √3 the magnitude of the
delta load (phase) current
B. For the delta connected load, the line current leads the delta load (phase) current by 30°
C. For the wye connected generator, the magnitude of the line-to-neutral (phase) voltage is √3
the magnitude of the line-to-line voltage
D. For the wye connected generator, the line-to-neutral (phase) voltage leads the line-to-line
voltage by 30°
Correct Answer: A
(Q5 Canvas) Problem 13: With regards to impedance transfer in a transformer, if 𝑇=𝑁𝑝/𝑁𝑠 denotes the turns
ratio, then which of the following statement is correct? 100pts
A. When the secondary impedance is moved to the primary side, the secondary impedance is
multiplied by 𝑇
B. When the secondary impedance is moved to the primary side, the secondary impedance is
multiplied by 𝑇^2
C. When the secondary impedance is moved to the primary side, the secondary impedance is
divided by 𝑇
D. When the secondary impedance is moved to the primary side, the secondary impedance is
divided by 𝑇^2
Correct Answer: B
(Q6 Canvas) Problem 14: For a wye-delta three phase transformer, which of the following is true? 100pts
Note: Letters in upper-case denote the primary side, while the letters in lower case denote the
secondary side.
A. 𝑽𝐴B is in phase with 𝑽𝑎𝑛 and 𝑽𝐴B leads 𝑽𝑎b by 30°
B. 𝑽𝐴B is in phase with 𝑽𝑎𝑛 and 𝑽𝐴B lags 𝑽𝑎b by 30°
C. 𝑽𝐴N is in phase with 𝑽𝑎b and 𝑽𝐴B leads 𝑽𝑎b by 30°
D. 𝑽𝐴N is in phase with 𝑽𝑎b and 𝑽𝐴B lags 𝑽𝑎b by 30°
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