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JATC Year 3: Motor Control Final > Motor Control Final Review Questions > Flashcards

Motor Control Final Review Questions Flashcards

1
Q

A ______ relay is a relay that not only maintains its contacts in the last position without a continuously energized coil, but also with a mechanical mechanism or remnant magnetism until it resets electrically.

a. frequency
b. latching
c. sequencing

A

b. latching

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2
Q

______ latching relays have a latch coil and an unlatch coil.

a. Impulse
b. Magnetic
c. Mechanical

A

c. Mechanical

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3
Q

The coils of mechanically latching relays are rated for continuous operation.

True or False

A

False

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4
Q

______ have contacts that prevent continuous power from being applied to the coil after it has been energized.

a. Coil clearing contacts
b. Holding contacts
c. Overload contacts

A

a. Coil clearing contacts

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5
Q

Wound rotor motor speed control is accomplished by inserting resistors in series with the ______ winding of the motor.

a. rotor
b. run
c. stator

A

a. rotor

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6
Q

To operate a wound rotor motor at full speed, the rotor windings must be ______.

a. connected
b. open
c. shorted together

A

c. shorted together

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7
Q

Single-phase motor speed control circuits use SCR or ______ to control power to the motor for speed control.

a. diacs
b. diodes
c. triacs

A

c. triacs

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8
Q

In a single-phase motor speed control, the thyristor controls power in the circuit by changing the ______ angle of the AC sine wave that drives the motor.

a. displacement
b. firing
c. phase

A

b. firing

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9
Q

A variable frequency drive provides a 48 hertz AC voltage to a 3-phase AC motor that has four poles per phase. What would be the synchronous speed of the motor with this voltage applied?

a. 1280 RPM
b. 1440 RPM
c. 1800 RPM

A

b. 1440 RPM

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10
Q

In a VFD, the ______ section of the VFD converts the incoming AC voltage into rectified DC voltage.

a. converter
b. DC bus
c. inverter

A

a. converter

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11
Q

Most new or upgraded DC systems use what type of starting method?

a. contactor
b. electronic DC drive
c. rheostat

A

b. electronic DC drive

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12
Q

When starting a DC motor with a rheostat, the current at the field winding is ______ and the current at the armature is ______.

a. high / high
b. high / low
c. low / high

A

b. high / low

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13
Q

During the operation of a DC rheostat motor starter, the resistance is ______ in the field winding and ______ in the armature until the motor is brought up to full speed.

a. increased / increased
b. increased / reduced
c. reduced / increased

A

b. increased / reduced

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14
Q

Most DC motor contactors consist of ______ set(s) of contacts.

a. one
b. two
c. three

A

a. one

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15
Q

The magnetic ______ coil produces a magnetic field between the breaking contacts that forces the arc up, increasing the length of the arc and causing it to dissipate faster.

a. blowout
b. contactor
c. overload

A

a. blowout

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16
Q

A 1-5 VDC analog device can be used in a 4-20 mA DC loop circuit if a 250 ohm resistor is connected across the input to the device and the 4-20 mA DC current is routed through the resistor. The current signal produces the proper voltage to operate the 1-5 VDC device.

True or False

A

True

17
Q

When analog control devices are located large distances from each other, which type of signal is preferable for installing the control wiring?

a. Current
b. Voltage

A

a. Current

18
Q

______ are analog output devices that document industrial and commercial process data .

a. Control valves
b. Recorders
c. Ultrasonic flow meter

A

b. Recorders

19
Q

Drag the green check mark to indicate the proper test equipment to use in troubleshooting analog pilot devices, selecting the most appropriate equipment for each device. (Note: Some devices may require two or more types of equipment.) Drag the red “x” to show items that are not appropriate for troubleshooting the device. Each box must contain a selection to receive full credit.

A
20
Q

AC, DC, and transistor-to-transistor logic (TTL) are the three most common types of output circuits used in controller ______ modules.

a. input
b. output

A

output

21
Q

Controller input and output modules have opto-isolation between the field device power and the controller or motor drive system power to eliminate noise and operational problems.

True or False

A

true

22
Q

Speed and ______ are two physical quantities that must be controlled in a motor drive.

a. direction
b. temperature
c. torque

A

c. torque

23
Q

Motor control systems that control motor speed without feedback data for torque or speed are called ______ control systems.

a. closed-loop
b. open-loop

A

b. open-loop

24
Q

The architecture of the PC and PLC systems are similar with both featuring a motherboard, memory, expansion slots, and a(n) ______.

a. HMI
b. monitor
c. processor

A

c. processor

25
Q

Which IEC standard programming language most closely replicates the control diagrams used in traditional magnetic motor control?

a. Function block diagrams
b. Instruction list
c. Ladder logic
d. Sequential function charts
e. Structured text

A

c.
Ladder logic

26
Q

Three-phase motors typically have slip, which is the difference between the rotational speed of the rotor of the motor and the rotational speed of the magnetic field in the stator of the motor. What is the slip of a synchronous motor?

a. 0 (zero)
b. 3%
c. 5%

A

a. 0

27
Q

______ in synchronous motors have two winding types, salient pole windings and amortisseur windings.

a. Rotors
b. Stators

A

a. rotors

28
Q

For a stepper motor with an angular resolution of 0.72° per step, indicate the number of discrete steps required to achieve complete 360° rotation of the shaft.

a. 4
b. 200
c. 500

A

c. 500

29
Q

Match the motor functions to the term that best describes that function.

  • The maximum amount of torque provided by a load that a stepper motor can withstand without moving from its position, with the stator energized.
  • The maximum amount of torque provided by a load that a stepper motor can withstand without moving from its position, with the stator de-energized.
  • The maximum number of steps the motor makes in one second.
  • The number of degrees that the motor moves per step.

Choices:
- Detent Torque
- Holding Torque
- Stepping Rate
- Step Angle

A

Holding Torque - - The maximum amount of torque provided by a load that a stepper motor can withstand without moving from its position, with the stator energized.

Detent Torque - - The maximum amount of torque provided by a load that a stepper motor can withstand without moving from its position, with the stator de-energized.

Stepping Rate - - The maximum number of steps the motor makes in one second.

Step Angle - - The number of degrees that the motor moves per step.

30
Q

What is the highest level of factory floor network architecture and provides an information layer for enterprise-wide data collection and program maintenance network?

a. ControlNet
b. DeviceNet
c. Ethernet

A

c. ethernet

31
Q

A specification for an Ethernet® network calls for a 100BaseT system. What type of cable would be used for this network?

a. Coaxial cable
b. Fiber-optic cable
c. STP (shielded twisted pair)
d. UTP (unshielded twisted pair)

A

d. UTP (unshielded twisted pair)

32
Q

Which troubleshooting technique is generally divided into two groups called power and information?

a. Block diagrams
b. Bracketing
c. Information funneling
d. Signal flow

A

d. Signal flow

33
Q

Which basic troubleshooting technique includes four levels of testing?

a. Block diagrams
b. Bracketing
c. Information funneling
d. Signal flow

A

c. Information funneling

34
Q

What kind of signal flow topology path is represented by Connections 1 and 2 and shows power feeds to the main switchgear block?

a. Convergent
b. Divergent
c. Feedback
d. Linear
e. Switched path

A

a. Convergent

35
Q

What kind of signal flow topology are paths 3 and 8?

a. Convergent
b. Divergent
c. Feedback
d. Linear
e. Switched path

A

c. Feedback

JATC Year 3: Motor Control Final (12 decks)

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