3B Midterm Prep

Question 1

Overload relay devices are normally rated to trip at specific current when surrounded by an ambient temperature of ___ AC.

Answer 1

40

Question 2

A ___ is a device used only periodically to remove electrical circuits from their supply source.

Answer 2

Disconnect

Question 3

___ overload relays are extremely quick to reset because they do not require a cooling-off period before being reset.

Answer 3

Magnetic

Question 4

Originally, most knife switches were made of ___, which required replacement after repeated arcing, heat generation, and mechanical fatigue.

Answer 4

copper

Question 5

Two-wire control is normally used for ___ installations where an immediate return to service after a power failure is required.

Answer 5

Remote or inaccessible

Question 6

One method that can be used to determine whether a transformer has failed is to measure the input and output ___.

Answer 6

voltages

Question 7

To obtain a control voltage of 120 VAC from a line voltage of 480 VAC, the two primary coils must be connected in ___.

Answer 7

series

Question 8

Transformers are used to increase generated ___ to a high level for transmission across the country and then decrease it to a low level for use by electrical loads.

Answer 8

voltage

Question 9

Low voltage transformer windings are marked with an ___.

Answer 9

X

Question 10

A ___ is a connection brought out of a winding at a point between its endpoints to allow the voltage or current ratio to be changed.

Answer 10

Tap

Question 11

In a delta-connected system, ___ of the three wires are normally connected to ground.

Answer 11

none

Question 12

Voltage between any two lines in a wye-connected AC generator is ___ multiplied by any of the individual phase voltages.

Answer 12

1.73

Question 13

A(n) ___ connection is a connection that has each coil end connected end-to-end to form a closed loop.

Answer 13

delta

Question 14

Each complete rotation of the ___ in a single phase (one wire) AC generator produces one complete alternating current cycle.

Answer 14

armature

Question 15

The three ends of a wye-connected AC generator can be safely connected at the ___ point because no voltage difference exists between them.

Answer 15

neutral

Question 16

A brush is the sliding contact the rides against the commutator segments or slip rings and is used to connect the ___ to the external circuit.

Answer 16

armature

Question 17

A(n) ___ is the movable coil of wire in a generator that rotates through the magnetic field.

Answer 17

armature

Question 18

Field windings are electromagnets used to produce the ___ field in a generator.

Answer 18

magnetic

Question 19

Commutator segments reverse the connections to the brushes every ___ cycle.

Answer 19

half

Question 20

A shunt-wound generator is a generator that has its field windings connected in ___(shunt) with the armature and the external circuit (load).

Answer 20

parallel

Question 21

All contacts can have a maximum of ___ break(s).

Answer 21

two

Question 22

Relays are available with 1 to ___ poles.

Answer 22

12

Question 23

Typical ___ life ratings are 100,000 to 500,000 operations.

Answer 23

contact

Question 24

Sulfidation increases the ___ of the contacts.

Answer 24

Resistance

Question 25

A ___ relay is a fast-operating single-pole, single-throw switch with normally open contacts hermetically sealed in a glass envelope.

Answer 25

Reed

Question 26

A ___ is a flow path through a valve.

Answer 26

way

Question 27

Solenoids usually fail due to electrical problems or ___

Answer 27

mechanical damage

Question 28

Magnetic coils are normally constructed of many turns of insulated ___ wire wound on a spool.

Answer 28

copper

Question 29

The left-hand rule states that if the fingers of the left hand are wrapped in the direction of the current flow of the coil, the thumb points to the magnetic ___ pole of the coil.

Answer 29

north

Question 30

For most solenoids, the minimum pick-up voltage is about ___ of the solenoid rated voltage

Answer 30

80%-85%

Question 31

A(n) ___ system is not a common application of temperature switches.

Answer 31

Air compression

Question 32

A ___ is not a basic actuator used on limit-switches.

Answer 32

contact pole

Question 33

A ___ level switch detects the dielectric variation when a product is in contact with the probe and when the product is not in contact with the probe.

Answer 33

capacitive

Question 34

A(n) ___ is the part of a switch that includes the written description of the switch’s operation

Answer 34

legend plate

Question 35

A ___ is not a common foot switch application

Answer 35

two hand safety circuit

Question 36

The dashed line method works well when the control contacts are close together and the circuit is relatively ___.

Answer 36

simple

Question 37

The ___ gate is a universal building block of digital logic

Answer 37

NAND

Question 38

No more than ___ load(s) should be placed in any circuit line between the power lines L1 and L2

Answer 38

one

Question 39

Additional start pushbuttons are connected in parallel using ___ logic with the existing start pushbuttons

Answer 39

NOR

Question 40

Two loads must not be connected in ___ in one line of a line diagram

Answer 40

series

Question 41

Electrical power must be ___ when electrical equipment is inspected, serviced, or repaired.

Answer 41

removed

Question 42

A(n) ___ signal word is used to indicate an imminently hazardous situation which, if not avoided, will result in death or serious injury

Answer 42

danger

Question 43

___ is the process of removing the source of electrical power and installing a lock which prevents the power from being turned on.

Answer 43

lock out tag out

Question 44

A(n)___ is a temporary or movable platform or structure for works to stand on

Answer 44

scaffold

Question 45

___ injuries suck dick and are the result of improper lifting procedures

Answer 45

back

Question 46

A(n) ___ is a device that detects insulation deterioration by measuring high resistance values under high test voltage conditions

Answer 46

megohmmeter

Question 47

Always check for the presence of ___ before taking any measurements.

Answer 47

voltage

Question 48

in most cases, diodes are tested with a ___

Answer 48

digital multi meter

Question 49

A(n)___ is a test instrument that provides a visual display of voltages

Answer 49

oscilloscope

Question 50

A ___ tester is a device that indicates approximate voltage level and type (AC or DC) by the movement and vibration of a pointer on a scale.

Answer 50

voltage

Question 51

A ___ is a diagram that shows a logical sequence of steps for a given set of conditions

Answer 51

flow chart

Question 52

A(n)___ indicates the beginning and end of a flow chart or section of a flow chart

Answer 52

ellipse

Question 53

A(n) ___ is a material that has very little resistance to current flow and permits electrons to move through it easily

Answer 53

conductor

Question 54

A(n) ___ is a letter or combination of letters that represents a word

Answer 54

abbreviation

Question 55

The primary function or a ___ diagram is to show how the distinct parts of a system relate

Answer 55

block

Question 56

The unit of capacitance

Answer 56

farads

Question 57

The electrical term used to describe the opposition to electron flow is ___

Answer 57

resistance

Question 58

Ohm’s law is used in circuits that contain ___

Answer 58

impedance

Question 59

A(n) ___ is an electronic component that allows current to pass through it in only one direction.

Answer 59

diode

Question 60

___ power is power absorbed and returned to a load due to its inductive and/or capacity properties.

Answer 60

Reactive