BCIT ELECTRICAL - DC LATEST
MACHINES LEVEL 3
EXAM QUESTIONS AND
ANSWERS 2026 - 2027
Excitation of a shunt motor is provided by field coils connected in
series with the armature.
False
When using NEMA subscripts, the convention of A1 positive in a
motor indicates
c.CCW rotation
When a DC generator and a DC motor are operated with the same
line voltage, polarity and direction of rotation, the respective
armature currents will be in opposite
True
What are two ways to reverse the direction of the force acting on the
armature conductors of a shunt motor?
d. both b and c
What is the MOST PRACTICAL method of reversing the direction
of rotation of a shunt motor?
b. Reverse the armature leads.
What happens to the direction of rotation in a shunt motor if the
polarity of the line terminals is reversed?
END OF
PAGE
1
, BCIT ELECTRICAL - DC LATEST
MACHINES LEVEL 3
EXAM QUESTIONS AND
ANSWERS 2026 - 2027
a. Rotation remains the same
Why must the field circuit of a shunt motor never be allowed to
become open while the motor is in operation?
B. The motor may accelerate to a dangerous runaway speed
To prevent runaway in a shunt motor, a(n) __________ is used.
B. Overspeed sensor
3. Which of the following is a typical use for a shunt motor?
D. All of the above
Shunt motors are commonly used for lathes, blowers, and drill
presses because they:
B. Operate at relatively constant speed under varying loads
Which application is LEAST likely to use a shunt motor?
D. Mine hoist
Series field windings consist of:
B. Small number of turns of large-gauge wire
What is the main difference between series and shunt excitation?
END OF
PAGE
2
, BCIT ELECTRICAL - DC LATEST
MACHINES LEVEL 3
EXAM QUESTIONS AND
ANSWERS 2026 - 2027
A. Series field strength depends on armature/load current; shunt field
strength is mostly independent of armature current
How can the direction of rotation of a series motor be reversed?
B. Reverse either the armature leads or the series field leads
Will changing the polarity of the line leads change the direction of
rotation of a series motor?
c. No, because both armature and field current reverse together
Why is a series motor unsuitable for constant-speed applications?
A. Its speed changes greatly with load
In practice, speed control of series motors is accomplished using:
B. Solid-state drives
The main advantage of a series motor is its very high starting
torque.
A. True
Why should a series motor always be mechanically coupled to the
driven load?
B. To prevent the motor from running away to dangerous speeds at no
load
END OF
PAGE
3
MACHINES LEVEL 3
EXAM QUESTIONS AND
ANSWERS 2026 - 2027
Excitation of a shunt motor is provided by field coils connected in
series with the armature.
False
When using NEMA subscripts, the convention of A1 positive in a
motor indicates
c.CCW rotation
When a DC generator and a DC motor are operated with the same
line voltage, polarity and direction of rotation, the respective
armature currents will be in opposite
True
What are two ways to reverse the direction of the force acting on the
armature conductors of a shunt motor?
d. both b and c
What is the MOST PRACTICAL method of reversing the direction
of rotation of a shunt motor?
b. Reverse the armature leads.
What happens to the direction of rotation in a shunt motor if the
polarity of the line terminals is reversed?
END OF
PAGE
1
, BCIT ELECTRICAL - DC LATEST
MACHINES LEVEL 3
EXAM QUESTIONS AND
ANSWERS 2026 - 2027
a. Rotation remains the same
Why must the field circuit of a shunt motor never be allowed to
become open while the motor is in operation?
B. The motor may accelerate to a dangerous runaway speed
To prevent runaway in a shunt motor, a(n) __________ is used.
B. Overspeed sensor
3. Which of the following is a typical use for a shunt motor?
D. All of the above
Shunt motors are commonly used for lathes, blowers, and drill
presses because they:
B. Operate at relatively constant speed under varying loads
Which application is LEAST likely to use a shunt motor?
D. Mine hoist
Series field windings consist of:
B. Small number of turns of large-gauge wire
What is the main difference between series and shunt excitation?
END OF
PAGE
2
, BCIT ELECTRICAL - DC LATEST
MACHINES LEVEL 3
EXAM QUESTIONS AND
ANSWERS 2026 - 2027
A. Series field strength depends on armature/load current; shunt field
strength is mostly independent of armature current
How can the direction of rotation of a series motor be reversed?
B. Reverse either the armature leads or the series field leads
Will changing the polarity of the line leads change the direction of
rotation of a series motor?
c. No, because both armature and field current reverse together
Why is a series motor unsuitable for constant-speed applications?
A. Its speed changes greatly with load
In practice, speed control of series motors is accomplished using:
B. Solid-state drives
The main advantage of a series motor is its very high starting
torque.
A. True
Why should a series motor always be mechanically coupled to the
driven load?
B. To prevent the motor from running away to dangerous speeds at no
load
END OF
PAGE
3
