Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Motion Control > Chapter 1 TEST > Flashcards

Chapter 1 TEST Flashcards

1
Q

List two examples of controlled variables for motion control applications and two examples from process control applications.

A

speed Position

Temperature and pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

An open loop system does not have a

A

feedback loop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T or F

The basic concept of feedback control is that an error must exist before some corrective action can be made.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A pressurized tank must maintain a gas at 325 PSI. A pressure sensor is used to measure the condition of the controlled variable. As the gas cools, the pressure in the tank decreases. When it drops to 300 PSI, a valve is opened, which allows steam to flow to a heat exchanger inside the tank. The additional steam heats the gas and causes pressure to rise.

A 
What is the controlled variable in this process?
Gas pressure
What is the manipulated variable in this process?
Steam flow
What is the setpoint?
325 PSI
What is the measured variable
pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Altering the________ variable causes the condition of the ______variable to change

A

manipulated

controlled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The manipulated variable and controlled variable are synonymous terms in a closed-loop system

A

FALSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

List another name for each of the following terms.

Motion control

Process control

Batch proces

A

Servo

Instrumentation / temperature

Sequential Process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The output of the measurement device is called the

A

Feedback signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Feed-forward control is seldom used except in combination with feedback control.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The control method used in ?servo/process? control applications is to sustain a constant condition of the controlled variable.

A

process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A DC series motor has____

A

highest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A cumulative compound motor has__ than a differential compound

A

higher starting torque

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Torque is produced by a motor when the load it is driving

does not move
moves
both

A

both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In a DC motor, an increasing mechanical load

Increases Armature current

has no effect on armature current
Decreases Armature current
A

Increases Armature current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Work is performed by a motor when the load it is driving ___________ moved a distance.
is not
Is
either answer

A

fis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When connecting a compound motor for operation, which leads are wired in parallel with the power supply?

A1 - A2
C1 - C2
F1 - F2
S1 - S2

A

F1 - F2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which of the following are functions of the brushes and commutator? _________

(choose all that apply)

to provide a path for field current flow

to provide a path for armature current flow
to connect and disconnect armature coils in sequence
A

t provide a path for armature current flow

to connect and disconnect armature coils in sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Refer to figure 5-14. work = distance x force

How much work in ft-lb is accomplished when a motor exerts a torque to lift a 473 pound load a distance of 28 feet. Do not include the unit designation ft-lb: example 3250

A

fr13244.0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Motor efficiency. Percent:efficiency=\frac{power:out}{power:in:}x:100 and power out = hp x 0.746kW

The power consumed by a motor is 10.652 kW , the motor produces 12 hp of output power. Round your answer to 2 decimal places and do not include the symbol %: example 94.52

A

t84.04

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The RPM that the rotating field moves around the Stater is called ____________ (two words )

A

synchronous speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In a synchronous motor, the DC excitation is applied to the stator or rotors magnetic field.

A

rotor’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

To change the rotation of a split-phase AC motor,_______.

reverse the main and auxiliary windings with respect to each other

reverse the power leads

both answers

A

reverse the main and auxiliary windings with respect to each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q 
Which components of a DC motor are not found in an AC motor?
	fan assembly
	Armature
	brushes and commutator
	field windings
A

brushes and commutator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

In a resistance start motor, current in the auxiliary winding always LEADS OR LAGS the current in the main winding.

A

Leads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Once the split-phase motor reaches [A] percent of its synchronous speed, the centrifugal switch [B] to [C] the________ windings.

A

75 to 80
opens
Disconnect
Auxiliary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The capacitor-start capacitor-run motor has how many capacitors?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In a synchronous motor, stator current will lead the applied voltage if the DC motor field is

over excited or under excited

A

overexcited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

In actual practice, the _____ leads are interchanged to reverse the direction of a universal motor.

A

Armature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Micro stepping is achieved by__________

A

both answers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The maximum number of steps a stepper motor can make in a second is called ___________

A

stepping rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The difference between the two classifications of PM motors is whether the rotor and field are made of permanent magnets or coils.

T F

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In a variable reluctance motor, if the salient poles are 15° apart and the rotor poles are 20° apart, the step angle is ____ degrees.

A

5

33
Q

In an AC Servo motor, the phase-shifted voltage is supplied to the ____ winding.

A

auxiliary

34
Q

The stepper motor is typically used in a(n) ____ -loop system.

A

open

35
Q

The speed of an AC Servo motor is changed by varying the voltage applied to ______

A

the auxiliary windings

36
Q

The amount of force required to move the rotor of the BDCM away from the held position is called

A

holding torque

37
Q

The speed of a wound armature PM motor is varied by changing the current applied to the

A

armature

38
Q

The speed at which a stepper motor turns is increased by ______ applied to the stator.

A

Increasing the stepper rate

39
Q

Find the cross product of vectors U and V such that U x V

U=0i+0j+1k

V= 0i+1j+0k

A

-1 0 0

40
Q

The speed at which a stepper motor turns is increased by ______ applied to the stator.

A

Increasing the voltage

41
Q

The Capacitor/resitance – start motor has the largest starting torque.

A

Capacitor

42
Q

The difference between the setpoint in the feedback signal is referred to as the
_______ signal, and is produced by the _________
detector.

A

error

error

43
Q

Which of the following influences causes a controlled variable to change?

the setpoint is adjusted
a load demand varies
A disturbance occurs
all three answers

A

all three answers

44
Q

The controller can be considered the brain of a closed-loop system.

A

True

45
Q

The _______ is sent to the final control element

A

control signal

46
Q

The objective of _____ control is to prevent the controlled variable deviating from the setpoint.

A

feed-forward

47
Q

The device that provides the muscle to perform the work in the closed loop system is referred to as the

A

actuator

48
Q

When the load on a DC shunt motor is increased, its speed will________ and the amount of torque developed will _________

A

decrease, increase

49
Q

Armature reaction is corrected by _________ , which is/are used to shift the neutral plane back to the proper position.

A

interpoles

50
Q

The interpoles are always connected in parallel with the armature

A

False

51
Q

When the motor speed increases, the CEMF in the Armature

increa/decreas

A

increase

52
Q

How much power is needed when a torque is applied to a 413 lb mass that is moving 33 ft for 2 minutes. Do not include the unit designation ft-lb/min: example 3250

A

6815.0

53
Q

AC motors that run at the same speed as the rotating magnetic field are called__________ motors.

A

synchronous

54
Q

During operation, if the resistance of a wound – rotor motor is set to zero, it performs very much differently than a squirrel cage motor.

A

False

55
Q

A(n) ____ in the external resistance of a wound – rotor motor causes an increase in the rotor resistance and therefore a reduction in the rotor current and speed.

A

increase

56
Q

A Duty Rating of 20 on the nameplate of a motor indicates that it is designated to run continuously for 24 hours a day.

A

False

57
Q

The A(amps) value on the nameplate for a three – phase motor indicates how much current will draw.

each phase

the entire motor

A

each phase

58
Q

Calculate the percent slip of an induction motor that has a synchronous speed of 3600 RPM and a motors speed of 3330 RPM. Compute your answer to 2 decimal places and do not include the % symbol: example 4.03

A

actual-synch
////
synch

7.5

59
Q

The CAP/RES – start motor is well suited for applications that require frequent starting loads, such as a refrigerator.

A

Capacitor

60
Q

In a synchronous motor, stator current will lead the applied voltage if the DC motor field is

A

overexcited

61
Q

Find the cross product of vectors U and V such that U x V

U=-2i+3j+4k
V= 3i+7j+2k

A

-22 4 4

62
Q

A differential compound motor has __________ then a cumulative compound motor.

A

better constant speed

63
Q

Which of the following conditions is compensated for by using the forward-control?

Excessive lag time
feedback signal
large disturbances
an error signal

A

Excessive lag time

large disturbances

64
Q

List one example of a measurement device for motion control application and one example for process control application

motion control

process contro

A

Tachometer

thermometer

65
Q

List two favorable features of synchronous motors.

A

power factor correction

constant speed

66
Q

The speed of an AC motor depends on the

of the power supply and the

A

frequency

number of poles

67
Q

What is the RPM speed of a single-phase 10-pole AC motor operating from a 60 Hz power source?

A

720.0

68
Q

The speed of a universal motor can be controlled by________.

Tapping a field coil at various points
Either answer
Using a variable resistor

A

Either answer

69
Q

The direction of the torque in a shaded – pole motor is towards the

A

Shaded pole

70
Q

The amortisseur windings of a synchronous motor perform a similar function to the bars and shorting rings of a squirrel cage induction motor.

A

TRUE

71
Q

If the stator’s magnetic field of the VR stepper motor moves clockwise, the rotor turns

A

counterclockwise

72
Q

A stepper motor with twice the step angle of a second stepper motor will turn at _____ the RPM if the stepper rate applied to both is the same.

A

TWICE

73
Q

The measured variable represents the condition of the controlled variable.

t f

A

True

74
Q

To change the direction of the DC shunt motor with compensating windings, you must interchange leads ___ or ____.

A

F1 and F2

A1 and A2

75
Q

In a DC series motor, if the Armature current is reduced to one half of its full load rating, the torque is ________

A

reduced

76
Q

A(n) ___ field must be established in a split-phase motor to produce the starting torque.

A

rotating

77
Q

When feedback and feedforward control are performed together, the primary function of the feedforward is to make corrections for ____disturbances, and feedback control is to make corrections for ________ disturbances.

A

measurable

unmeasurable

78
Q

A DC shunt motor operating at 240 V draws 4.5 A. It has an output of 1 hp. Its efficiency is_____ %.

A

69

Motion Control (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions