6th Final

Question 1

In a shunt relay, the size of the air gap between the coil and the armature determines the

Answer 1

voltage needed to operate the contactor

Question 2

In a power supply, the function of a capacitor is to ________ energy

Answer 2

Store and release

Question 3

When a junction diode conducts, electrons move ______ the junction and holes move _______ the junction.

Answer 3

Toward; toward

Question 4

a transistor operates as a switch, it is ON when it operates in the ______ region and OFF when it operates in the ______ region.

Answer 4

Saturation: cutoft

Question 5

The function of a float switch is to indicate

Answer 5

liquid level

Question 6

good general practice for localizing trouble in logic systems includes

Answer 6

Performing the easy tests first

Question 7

The problem with ripple counters is that the

Answer 7

Propagation delay is cumulative

Question 8

Unlike a RAM, a ROM

Answer 8

Stores data that do not change

Question 9

If you double the distance between two magnetic poles, the magnetic force is

Answer 9

reduced to 25%

Question 10

The binary system is based on the number______ _The hexadecimal system commonly used with PLCs is based on the number.

Answer 10

2, 16

Question 11

The maximum forward current in most diodes causes a forward voltage drop of _____ V

Answer 11

1.00

Question 12

Which of the following cells has the shortest service life?

Answer 12

Lead-acid

Question 13

Commutation is the

Answer 13

reversal of current in a motor’s armature

Question 14

The most common transistor connection is the common_____ because it provides _____ gain in voltage and current.

Answer 14

Emitter, high

Question 15

Once you understand how a PLC system works, the next step in troubleshooting it is to

Answer 15

gather information

Question 16

The The essential parts of an electrochemical cell are _____ and ______

Answer 16

Electrolyte, electrodes of different metals

Question 17

A device commonly used for converting parallel data to serial data is the

Answer 17

Multiplexer

Question 18

To protect yourself when working with cells and batteries, you should always be aware that the

Answer 18

Battery may produce explosive gases

Question 19

Choose 3 ways that are used to interpret measurement readings:

Answer 19

Median
Mode
Mean

Question 20

Before installing a new field coil in a machine, you should

Answer 20

determine the polanty of the new coil

Question 21

In a series regulator, the control circuit must keep the transistor______ in order to maintain a constant voltage across the load

Answer 21

Forward biased

Question 22

The movable magnetic arm of a relay is called the

Answer 22

Armature

Question 23

The best instrument for viewing many logic levels at once is the

Answer 23

Logic analyzer

Question 24

Mounting a solenoid from the end

Answer 24

improves its pertormance

Question 25

When a relay operates, Its NC contacts

Answer 25

open and remain open

Question 26

The color band or dot on a DO semiconductor package indicates the

Answer 26

n-type region

Question 27

Items that are important in applying electrical control components in the assembly of a machine?

Answer 27

• Condut ill, as set up in electrical standards, should not be exceeded •Care should be taken in pulling conductors through conduit and fittings so that no conductor insulation is cut or scraped •A sufficient number of terminal block checkpoints should be provided.

Question 28

Printed circuit boards having several layers are generally _______ than single-layer boards.

Answer 28

More complex in function

Question 29

If an I/O module supplies current, it is considered an ______ module

Answer 29

sourcing

Question 30

The purpose of laws relating to safety are to ensure that employers will provide a safe working environment for workers.

Answer 30

True

Question 31

A shunt voltage regulator maintains a constant voltage across the load by varying the ____ a path parallel to the load.

Answer 31

Current in

Question 32

The base in an non bipolar junction transistor is made of _____ -type material lightiy doped with _____ material

Answer 32

p ; acceptor

Question 33

Raising the temperature of a semiconductor material _______ its _______

Answer 33

Increases, conductivity

Question 34

Your first step in troubleshooting a solid-state system should be to

Answer 34

Gather information

Question 35

Which part of a de armature is made of copper bars that are insulated from each other?

Answer 35

Commutator

Question 36

Semiconductor failures caused by high temperatures usually occur

Answer 36

in a fraction of a second

Question 37

In an ac circuit, an SCR conducts during ______ of the cycle.

Answer 37

either half but not both halves

Question 38

The final step of a PLC scan involves

Answer 38

writing the output image table

Question 39

A programmable logic array consists of many______ that can be connected in varlous ways by ______

Answer 39

Logic gates, fusible links

Question 40

Most semiconductors can be damaged by an accidentally applied potential difference as low as_______ volts

Answer 40

100

Question 41

In ladder logic, the output instruction that looks like a coil is called

Answer 41

output energize

Question 42

12-V automotive (lead-acid) battery is overcharging if the voltage between the terminals is more than ______ volts while the

Answer 42

15:0

Question 43

Two types of safety control techniques are multiple start devices in series and redundant start devices in case of failure of one device

Answer 43

False

Question 44

A programmable logic controller is a device that

Answer 44

responds to status changes in a system

Question 45

The field windings in a de compound motor are connected so that _____ with the armature.

Answer 45

one is in parallel and one is in senes

Question 46

______ moves the coded data string bit at a time through one wire:

Answer 46

Serial transmission

Question 47

The most important tool a maintenance technician can possess is a(n)

Answer 47

documentation package

Question 48

The advantage of using and R-S flip-flop with a mechanical switch is that the flip-flop _____ the output when the switch changes.

Answer 48

Eliminates extra pulses from

Question 49

The first step in developing a PLC system to meet given specifications is

Answer 49

sizing the system

Question 50

of the most common types of IC voltage regulators has three terminals and is available in the most common preset voltages, ranging from. ______ to _______

Answer 50

5. 24