EEE 360 Midterm Exam Questions and 100% Correct Answers 2026/27
Latest - Arizona State University
Highlight=100; Red = -50; Blue = 50; Black = 25
1. For a given synchronous machine, corresponding to a stator current value of 𝐼𝑠𝑡𝑎, the value
of the armature reaction is 𝑋𝑎𝑟𝑚. For everything else remaining the same, if the stator
current now becomes 2 × 𝐼𝑠𝑡𝑎, what will be the new value of armature reaction?
a. 𝑋𝑎𝑟𝑚
b.
c. 2 × 𝑋𝑎𝑟𝑚
d. Cannot be determined
2. As the speed of an alternator increases:
a. the frequency increases
b. the frequency decreases
c. the frequency remains constant, but power factor decreases
d. none of the above
3. The driving power from the prime mover driving the alternator is lost but the alternator
remains connected to the supply network and the field supply also remains on. The
alternator will
a. get burnt
b. behave as an induction motor but will rotate in the opposite direction
c. behave as a synchronous motor and will rotate in the same direction
d. behave as a synchronous motor but will rotate in a reverse direction to that
corresponding to generator action
4. Maximum electric power output of a synchronous generator is:
𝑋𝑠𝑦𝑛
a. 𝐸𝑔𝑒𝑛𝑉𝑡
𝑉2
𝑡
b. 𝑋𝑠𝑦𝑛
2
𝐸𝑔𝑒𝑛
c. 𝑋𝑠𝑦𝑛
d.
EEE 360 Midterm Exam
, 5. Consider the following statements about a three-phase synchronous generator:
1. Typically, the power angle of the synchronous generator is about 30 degrees
2. In order to synchronize and interconnect to the network, the synchronous
generator has just to be started by a mechanical device and connected to the
network
3. Reactive power is regulated by the regulation of the induced voltage by the rotor
DC excitation current
4. The brushless excitation systems use an AC alternator and rectifiers mounted on
the generator shaft to produce DC needed for the field windings on the rotor.
Regarding the above statements:
a. 1 alone is correct
b. 2 alone is incorrect
c. 2 and 4 are incorrect
d. All four are correct
6. Transmission efficiency increases as:
a. Voltage and power factor both increase
b. Voltage and power factor both decrease
c. Voltage increases but power factor decreases
d. Voltage decreases but power factor increases
7. When the power is to be transmitted over a distance of 300 km, the transmission voltage
should be in the range:
a. 34.5 kV - 69 kV
b. 69 kV - 115 kV
c. 115 kV - 138 kV
d. 161 kV – 230 kV
8. Step-up substations are associated with:
a. Distributors
b. Consumer location
c. Concentrated load
d. Generating stations
EEE 360 Midterm Exam
Latest - Arizona State University
Highlight=100; Red = -50; Blue = 50; Black = 25
1. For a given synchronous machine, corresponding to a stator current value of 𝐼𝑠𝑡𝑎, the value
of the armature reaction is 𝑋𝑎𝑟𝑚. For everything else remaining the same, if the stator
current now becomes 2 × 𝐼𝑠𝑡𝑎, what will be the new value of armature reaction?
a. 𝑋𝑎𝑟𝑚
b.
c. 2 × 𝑋𝑎𝑟𝑚
d. Cannot be determined
2. As the speed of an alternator increases:
a. the frequency increases
b. the frequency decreases
c. the frequency remains constant, but power factor decreases
d. none of the above
3. The driving power from the prime mover driving the alternator is lost but the alternator
remains connected to the supply network and the field supply also remains on. The
alternator will
a. get burnt
b. behave as an induction motor but will rotate in the opposite direction
c. behave as a synchronous motor and will rotate in the same direction
d. behave as a synchronous motor but will rotate in a reverse direction to that
corresponding to generator action
4. Maximum electric power output of a synchronous generator is:
𝑋𝑠𝑦𝑛
a. 𝐸𝑔𝑒𝑛𝑉𝑡
𝑉2
𝑡
b. 𝑋𝑠𝑦𝑛
2
𝐸𝑔𝑒𝑛
c. 𝑋𝑠𝑦𝑛
d.
EEE 360 Midterm Exam
, 5. Consider the following statements about a three-phase synchronous generator:
1. Typically, the power angle of the synchronous generator is about 30 degrees
2. In order to synchronize and interconnect to the network, the synchronous
generator has just to be started by a mechanical device and connected to the
network
3. Reactive power is regulated by the regulation of the induced voltage by the rotor
DC excitation current
4. The brushless excitation systems use an AC alternator and rectifiers mounted on
the generator shaft to produce DC needed for the field windings on the rotor.
Regarding the above statements:
a. 1 alone is correct
b. 2 alone is incorrect
c. 2 and 4 are incorrect
d. All four are correct
6. Transmission efficiency increases as:
a. Voltage and power factor both increase
b. Voltage and power factor both decrease
c. Voltage increases but power factor decreases
d. Voltage decreases but power factor increases
7. When the power is to be transmitted over a distance of 300 km, the transmission voltage
should be in the range:
a. 34.5 kV - 69 kV
b. 69 kV - 115 kV
c. 115 kV - 138 kV
d. 161 kV – 230 kV
8. Step-up substations are associated with:
a. Distributors
b. Consumer location
c. Concentrated load
d. Generating stations
EEE 360 Midterm Exam
