Motors & Controls MCQs
Motors & Controls MCQs
These Motors & Controls multiple-choice questions and their answers will help you strengthen your grip on the subject of Motors and Controls. You can prepare for an upcoming exam or job interview with these Motors & Controls MCQs.
So scroll down and start answering.
1: How many times does AC current change its direction of flow in a day?
A. It changes direction 72 times in a day.
B. It cycles
C. It changes direction 48 times in a day
D. It changes direction 24 times in a day
2: How many times does AC current change its direction per second?
A. 24
B. 12
C. 48
D. 60
3: What is an AC Motor?
A. A motor operating on AC current that only flows in one direction
B. A motor operating on AC current that flows in either direction
C. A motor operating on DC current that flows in either direction
D. A motor operating on DC current that only flows in one direction
4: What does ARMATURE INDUCTANCE, MH stand for?
A. Angular momentum in henries per meter
B. Armature inductance in milli-henries (saturated).
C. Area of magnetic field in henries per meter
D. Amplitude modulation in henries per meter
5: What does ARMATURE INDUCTANCE, MH refer to?
A. Speed of armature
B. Armature inductance in milli-henries (saturated)
C. Current armature
D. Width of armature
6: What is the name of the current that flows in the armature winding of a DC motor?
A. Field current
B. Armature current
C. Motor current
D. Commutation current
7: What is the unit of measurement for armature resistance?
A. Henry
B. Ohms
C. Volt
D. Ampere
8: What is armature resistance?
A. The measure of armature resistance in ohms at 0 degrees C (cold)
B. The measure of armature resistance in ohms at 25 degrees C (cold)
C. The measure of armature resistance in amperes at 25 degrees C (cold)
D. The measure of armature resistance in volts at 25 degrees C (cold)
9: What is the name of the effect that reduces the torque capacity of a DC motor?
A. Armature Reaction
B. Electromagnetic induction
C. Eddy current
D. Faraday's law of induction
10: What is armature resistance measured in?
A. Volts
B. Amps
C. Watts
D. Ohms
11: What does ARMATURE RESISTANCE mean?
A. The flux in the armature winding of a DC machine.
B. AC against DC
C. The resistance of the armature winding of a DC machine.
D. The current in the armature winding of a DC machine
12: What is the force or load that is applied to the motor shaft in a direction parallel to the axis of the shaft called?
A. Horsepower
B. Angular momentum
C. Axial thrust
D. Torque
13: How is the amount of active iron in a motor usually increased or decreased?
A. By lengthening or shortening the stator.
B. By increasing or decreasing the width of the rotor and stator.
C. By increasing or decreasing the length of the rotor and stator.
D. By lengthening or shortening the rotor and stator.
14: How is the amount of steel in a motor's stator and rotor increased or decreased?
A. By increasing or decreasing the magnetic field around the rotor and stator
B. By adding or removing iron from the rotor and stator
C. By lengthening or shortening the rotor and stator
D. By changing the direction of the current through the rotor and stator
15: What does an air pressure switch do?
A. Detects a clogged filter
B. Used on motors with blowers to measure the difference in pressure across the filter
C. To detect a change in pressure
D. To measure the pressure of the air
16: What does an air temperature switch do?
A. It turns the motor on and off
B. It detects the temperature of the surrounding air
C. It detects the temperature of the exhausted air
D. It cools the motor
17: What is the maximum altitude at which a NEMA standard motor can operate?
A. 3,000 meters (9,850 feet)
B. 1,000 meters (3,300 feet)
C. 2,000 meters (6,600 feet)
D. 500 meters (1,650 feet)
18: What is the standard NEMA rating for ambient temperature?
A. Not to exceed 30 degrees C
B. Not to exceed 40 degrees C
C. Should be between 10-15 degrees C
D. Not to exceed 60 degrees C
19: What is an anti-friction bearing?
A. A bearing that uses liquid lubrication
B. A type of roller bearing
C. A bearing utilizing rolling elements between the stationary and rotating assemblies
D. A device that reduces friction between two surfaces
20: What does the term "Armature" refer to in the context of a DC or universal motor?
A. The power supply of the motor.
B. The speed controller of the motor.
C. The portion of the magnetic structure which does not rotate.
D. The portion of the magnetic structure which rotates.
21: What is the purpose of an armature in a DC or universal motor?
A. The armature is stationary and allows electrons to flow through the motor
B. The armature increases the speed of the motor
C. The armature rotates and creates magnetic flux
D. The armature is made of rare earth metals and improves the motor's efficiency
22: What does ARMATURE CURRENT mean?
A. Full load armature circuit current.
B. Voltage produced by an armature coil.
C. Current that flows through the armature.
D. A device used to create armature current.
23: What is the back end of a motor?
A. The back end of a motor is the end that contains the brakes.
B. The back end of a motor is the end that houses the transmission.
C. The back end of a motor is the end that contains the engine.
D. The back end of a motor is the end that carries the coupling or driving pulley.
24: What is the back end of a motor also called?
A. The end that carries the alternator
B. The end that carries the gearbox
C. The end that carries the engine
D. The end that carries the coupling or driving pulley
25: What does BASE SPEED, RPM stand for?
A. Base Speed, Religious People per Minute
B. Base Speed, Roman Catholics per Minute
C. Base Speed, Revolutions per Minute
D. Base Speed, Republicans per Minute
26: What are bearings used for?
A. To provide a rigid support for the output shaft
B. To act as the connection point between the rotating and stationary elements of a motor
C. To reduce friction and wear while supporting rotating elements
D. To increase friction and wear while supporting rotating elements
27: What is the main purpose of Bearings?
A. Reduce friction and wear while supporting rotating elements
B. Provide a relatively rigid support for the output shaft
C. Support the output shaft
D. Connect the rotating and stationary elements of a motor
28: BEARING LIFE rating is the life in hours or revolutions in which:
A. 10% of the bearings selected will obtain or exceed.
B. 100% of the bearings selected will obtain or exceed.
C. 50% of the bearings selected will obtain or exceed.
D. 90% of the bearings selected will obtain or exceed.
29: What is the purpose of brakes?
A. To bring a running motor to a standstill and/or hold a load.
B. To start a motor
C. To increase the speed of a motor
D. To make a motor run more smoothly
30: What is the braking torque?
A. The torque required to Accelerate a motor
B. The torque required to bring a motor down to a standstill.
C. The torque required to start a motor.
D. The torque required to keep a motor running.
31: What is the definition of BREAKDOWN TORQUE?
A. The maximum torque a motor will develop at rated voltage without a relatively abrupt drop or loss in speed.
B. The minimum torque a motor will develop at rated voltage without a relatively abrupt drop or loss in speed.
32: What is the maximum torque a motor will develop at rated voltage without a relatively abrupt drop or loss in speed?
A. Torque
B. Maximum torque
C. Loss in speed
D. Breakdown torque
33: What is the purpose of a brush in a commutated motor?
A. Provide lubrication for the armature
B. Regulate the speed of the motor
C. Increase the torque of the motor
D. Conduct current from the power supply to the armature windings
34: What is the torque required to bring a motor down to a standstill called?
A. Brake torque
B. Running torque
C. Holding torque
D. Breaking torque
35: What does the capacitor do in a capacitor start motor?
A. Provide better phase relation
B. Give the motor a split-phase start
C. Reverse the motor at rest
D. Provide more power input
36: What is the main difference between the capacitor start single-phase motor and the split phase start motor?
A. The capacitor start single-phase motor has a capacitor in series with the running winding.
B. The capacitor start single-phase motor has a capacitor in parallel with the starting winding.
C. The capacitor start single-phase motor has a capacitor in series with the starting winding.
D. The capacitor start single-phase motor does not have a capacitor in series with the starting winding.
37: What does the CE designation show for a product?
A. That it is a limited edition product.
B. That it was made in the CE () century.
C. That it meets European Standards for safety and environmental protection.
D. That it is only available in Europe
38: What does CE stand for?
A. Economic Cooperation
B. Environmentally Conscious
C. Equal Chance
D. European Standards
39: What is the minimum voltage amount that begins the process of ionization of motor windings?
A. CIV
B. Process of Ionization
C. Corona Inception Voltage
D. Minimum Voltage Amount
40: What is CIV?
A. Continuous Inverter Voltage
B. Corona Inception Voltage
C. Corona Injection Voltage
D. Converter Inverter Voltage
41: What is a centrifugal cutout switch?
A. A device that regulates the flow of electricity in a circuit.
B. A centrifugally operated automatic mechanism used in conjunction with split phase and other types of single-phase induction motors.
C. A device used to connect or disconnect the starting winding of an induction motor.
D. A device that increases the voltage in an electrical circuit.
42: What is a clutch?
A. A mechanical device for engaging and disengaging a motor.
B. A type of fastener
C. A device for starting a car
D. A device for stopping a car
43: What does the Canadian Standards Association do?
A. Sets specific standards for products used in Canada
B. Produces standards for products used in the United States
C. Produces standards for products used in Canada
D. Produces standards for products used in Europe
44: Which of the following is true about "C" Flange?
A. The "C" flange is a NEMA standard design.
B. The "C" flange is used with close-coupled pumps only.
C. The "C" flange is available only with feet.
D. The "C" flange is used to connect the pump on the motor.
45: What is the "C" flange used for?
A. Assault weapons
B. Electrical sockets
C. To mount close-coupled pumps and speed reducers
D. Doors
46: What is the definition of cogging?
A. A measure of how much torque is required to rotate a motor armature.
B. The interaction between the field coils and armature coils in a DC motor.
C. The tendency of a motor to slow down when overloaded.
D. Rotation occurring in jerks or increments rather than smooth motion.
47: What is the function of a canopy on a motor?
A. To reduce the noise emitted by the motor
B. To increase the aerodynamic efficiency of the motor
C. To protect it from liquids or solids that might drop onto the motor
D. To improve the cooling of the motor
48: What is the canopy?
A. The umbrella for the motor
B. A protective cover that protects the motor from liquids or solids
C. The motor being mounted vertically
D. A liquid or solid
49: What is cogging?
A. Rotation of a person on a swing
B. Rotation occurring in jerks or increments rather than smooth motion.
C. Rotation occurring in smooth motion
D. Rotation of planets around the sun
50: What is the peak of the current wave reached ahead of the voltage wave in an alternating-current circuit?
A. Resistor
B. Inductor
C. Capacitor
D. Transistor
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