study guide

Question 1

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

a.
contactor

b.
electronic DC drive

c.
rheostat

Answer 1

electronic dc drive

Question 2

When starting a DC motor with a rheostat, the current at the field winding is ? and the current at the armature is ? .
Select one:

a.
high / high

b.
high / low

c.
low / high

Answer 2

high/low

Question 3

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.
Select one:

a.
increased / increased

b.
increased / reduced

c.
reduced / increased

Answer 3

increased/reduced

Question 4

Most DC motor contactors consist of ? set(s) of contacts.
Select one:

a.
one

b.
two

c.
three

Answer 4

one

Question 5

Arc chutes typically absorb ? than 80% of the energy released during the interruption of current flow as the contacts open.
Select one:

a.
greater

b.
less

Answer 5

greater

Question 6

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.
Select one:

a.
blowout

b.
contactor

c.
overload

Answer 6

blowout

Question 7

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

a.
Current

b.
Voltage

Answer 7

current

Question 8

? are analog output devices that document industrial and commercial process data .
Select one:

a.
Control valves

b.
Recorders

c.
Ultrasonic flow meter

Answer 8

recorders

Question 9

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

a.
input

b.
output

Answer 9

output

Question 10

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.
Select one:
True
False

Answer 10

true

Question 11

Speed and ? are two physical quantities that must be controlled in a motor drive.
Select one:

a.
direction

b.
temperature

c.
torque

Answer 11

torque

Question 12

Motor control systems that control motor speed without feedback data for torque or speed are called ? control systems.
Select one:

a.
closed-loop

b.
open-loop

Answer 12

open loop

Question 13

A motor control system that uses a tachometer to control the speed of the motor is called a(n) ? system.
Select one:

a.
closed-loop

b.
open-loop

Answer 13

closed loop

Question 14

Drive, comparator, sensor, and amplifier are the four parts of a(n) ? system.
Select one:

a.
closed-loop

b.
open-loop

Answer 14

closed loop

Question 15

Tachometer/generators and optical encoders are two types of devices that are generally used to provide speed reference signals in a(n) ? speed control system.
Select one:

a.
closed-loop

b.
open-loop

Answer 15

closed loop

Question 16

In a closed-loop speed control system, the ? is the desired speed selected for the motor connected to the drive.
Select one:

a.
feedback speed value

b.
feedback summing amplifier

c.
set point speed value

Answer 16

set point value

Question 17

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

a.
HMI

b.
monitor

c.
processor

Answer 17

processor

Question 18

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

a.
Function block diagrams

b.
Instruction list

c.
Ladder logic

d.
Sequential function charts

e.
Structured text

Answer 18

ladder logic

Question 19

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?
Select one:

a.
0 (zero)

b.
3%

c.
5%

Answer 19

zero

Question 20

? in synchronous motors have two winding types, salient pole windings and amortisseur windings.
Select one:

a.
Rotors

b.
Stators

Answer 20

rotors

Question 21

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

a.
ControlNet

b.
DeviceNet

c.
Ethernet

Answer 21

ethernet

Question 22

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

a.
Coaxial cable

b.
Fiber-optic cable

c.
STP (shielded twisted pair)

d.
UTP (unshielded twisted pair)

Answer 22

utp

Question 23

All ? cable systems include device power and data integrated into a single cable system.
Select one:

a.
ControlNet

b.
DeviceNet

c.
Ethernet

Answer 23

DeviceNet

Question 24

Both ControlNet and flat cable DeviceNet require cable terminators or end terminators to prevent data signals from reflecting back through the cable.
Select one:
True
False

Answer 24

True

Question 25

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

a.
Block diagrams

b.
Bracketing

c.
Information funneling

d.
Signal flow

Answer 25

signal flow

Question 26

Which basic troubleshooting technique includes four levels of testing?
Select one:

a.
Block diagrams

b.
Bracketing

c.
Information funneling

d.
Signal flow

Answer 26

information funneling

Question 27

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

Answer 27

latching

Question 28

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

a.
Impulse

b.
Magnetic

c.
Mechanical

Answer 28

mechanical

Question 29

The coils of mechanically latching relays are rated for continuous operation.
Select one:
True
False

Answer 29

False

Question 30

? 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

Answer 30

coil clearing contacts

Question 31

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

a.
rotor

b.
run

c.
stator

Answer 31

rotor

Question 32

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

a.
connected

b.
open

c.
shorted together

Answer 32

shorted together

Question 33

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

a.
diacs

b.
diodes

c.
triacs

Answer 33

triacs

Question 34

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

Answer 34

firing

Question 35

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

Answer 35

1440

hertz X 120 divided by the number of poles

Question 36

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

a.
converter

b.
DC bus

c.
inverter

Answer 36

converter