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Flashcards in Electrical Deck (387)
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0
Q

Use a _____ when you work in a damp or wet location

A

Dry wooden platform to sit or stand on

1
Q

If a person forms a closed circuit through which current can flow, and the power source supplies a voltage causing current to flow, a voltage of _____ or less, the person will be killed

A

115 volt

2
Q

Place ___ between you and the wood surface you’re working on

A

Rubber matting or other non conductive material

3
Q

What kind of tools and flashlight should you use when working on exposed electrical equipment

A

Insulated tools Nonmetallic flashlight

4
Q

Electric shock may be avoided by using safety equipment such as ____

A

Deck coverings and rubber gloves

5
Q

Prevents electrical shock to anyone who may touch bare, energized, or ungrounded circuits

A

Insulated deck covering

6
Q

Rubber floor matting must conform to

A

Military specification Mil-M-15562

7
Q

Gives approved deck coverings for every space

A

NSTM, chapter 634, table 634-1

8
Q

Repair defective matting by ____

A

Covering the affected area with a new piece of matting

9
Q

Foreign substances on matting contaminate or impair its ____

A

Dielectric properties

10
Q

The dielectric properties of matting can be impaired or destroyed by ____

A

Oil, embedded metal chips, cracks, holes, or other defects

11
Q

The primary feature discriminating one class of glove from another

A

Maximum safe voltage of the glove which is determined by its thickness

12
Q

Class 0 gloves have a maximum safe voltage of _____ and labeled ____

A

1000 volts Red

13
Q

A class 1 glove has a maximum safe voltage of _____ and is labeled _____

A

7500 volts White

14
Q

A class II glove has a maximum safe voltage of ____ and is labeled _____

A

17500 volts Yellow

15
Q

A class III glove has a maximum safe voltage of _____ and is labeled _____

A

26500 volts Green

16
Q

To inspect rubber gloves for tears, snags, punctures, or leaks that are not obvious _____

A

Hold the glove downward, grasp the glove cuff, and flip the glove upward to trap air inside the glove. Roll or fold the cuff to seal the trapped air inside, then squeeze the inflated glove and inspect it for damage

17
Q

For additional info on rubber gloves, refer to ______

A

NSTM, chapter 300

18
Q

Who must approve work to be done on energized circuits

A

CO

19
Q

Coat metallic hand tools with _____

A

Plastisol or cover them with two layers of rubber or vinyl plastic tape, half-lapped

20
Q

When working on live or hot circuits, you must be ____

A

Supervised and aware of the danger involved

21
Q

Refer to _____ for instructions on the use of plastisol

A

NSTM, chapter 631

22
Q

If you don’t have enough time to apply plastisol or tape ____

A

Cover the tool handles and their exposed parts with cambric sleeving, synthetic resin flexible tubing, or suitable insulation

23
Q

In a shipboard real ungrounded system, the factors of _____ must be considered

A

Resistance (R) Capacitance (C)

24
Q

Insulation resistance of a system is periodically measured with ______

A

500-volt DC megger

25
Q

If you are using a megger to check for ground in the system, and you get a reading of _____, you can conclude that no low resistance ground exists

A

50000 ohms resistance

26
Q

System capacitance exists in parallel with ____

A

Resistance

27
Q

The main reason we ground power tools and equipment is for ____

A

Safety

28
Q

Proper grounding can prevent lethal shocks by ____

A

Limiting voltages due to line surges or unintentional contact with higher voltage lines

29
Q

When using a multimeter to check continuity of the ground conductor from the tool case to the dummy receptacle, you should make sure the reading is ____

A

Less than 1 ohm

30
Q

Isolated receptacle circuits are limited to _____ in length

A

1500 feet

31
Q

Isolated receptacle circuits limit ground leakage currents to _____

A

10mA

32
Q

Definition of electricity

A

Force that causes electrons to move from one atom to another

33
Q

Electrons have a ____ charge

A

Negative

34
Q

Protons have a _____ charge

A

Positive

35
Q

Most atoms have an equal number of ______

A

Electrons and protons

36
Q

Electrons in the _____ can become free of their orbit

A

Outer band

37
Q

As free electrons move from one atom to the next an ____ is produced

A

Electric current

38
Q

Materials that permit many electrons to move freely

A

Conductors

39
Q

Materials that allow only a few electrons to move freely

A

Insulators

40
Q

An atom with an equal number of electrons and protons

A

Electrically neutral

41
Q

Act like a conductor when external force is applied in one direction and act like an insulator when the external force is applied in the opposite direction

A

Semiconductor

42
Q

Caused by an absence or excess of electrons

A

Positive or negative charge

43
Q

Atom that has gained or has an excess of electrons

A

Negative charge

44
Q

An atom that has lost or has an absence of electrons

A

Positive charge

45
Q

The force of attraction or repulsion depends on the strength of the charged bodies and the distance between them

A

Coulomb’s law of charges

46
Q

The flow of free electrons in a conductor from one atom to the next atom in the same general direction is referred to as ____

A

Current

47
Q

Current is designated by the symbol _____

A

I

48
Q

The number of electrons that pass through a cross section of a conductor in one second determines ____

A

Current

49
Q

Current is measured in _____

A

Amperes or amps

50
Q

Unit abbreviation for amps

A

A

51
Q

In mathematical equations amps is represented by

A

I

52
Q

6.28 x 10^18 electrons moving through a cross section of a conductor in one second equals _____

A

One amp

53
Q

Conventional current flow states that current flows from _____ to _____

A

Positive to negative

54
Q

Electron flow states that current flows from ____ to ____

A

Negative to positive

55
Q

Continuous flow of electrons in one direction

A

Direct current

56
Q

When the electrons flow first in one direction, then reverse direction and flow the opposite direction

A

Alternating current

57
Q

The force required to make electrons flow through a conductor is called ____

A

Difference in potential, electromotive force (emf), or voltage

58
Q

Unit of measurement for voltage

A

Volts

59
Q

Unit abbreviation for volts

A

V

60
Q

In mathematical equations volts is represented by _____

A

E or V

61
Q

Voltage is usually indicated symbolically on an engineering drawing with a ______

A

Battery symbol

62
Q

On the symbol for a battery, two lines indicate ______

A

The terminals of a battery

63
Q

The two lines on a battery symbol, the longer line represents _____

A

Positive terminal

64
Q

Six methods of producing voltage

A

Friction Pressure Heat Light Chemical action Magnetism

65
Q

Produces voltage by rubbing certain materials together

A

Friction

66
Q

Produces voltage by squeezing crystals of certain substances

A

Pressure (piezoelectricity)

67
Q

Produces voltage by heating the joint where two unlike metals are joined

A

Heat (thermoelectricity)

68
Q

Produces voltage by light striking photosensitive substances

A

Light (photo electricity)

69
Q

Produces voltage by chemical reaction in a battery cell

A

Chemical action

70
Q

Produces voltage in a conductor when the conductor moves through a magnetic field, or a magnetic field moves through a conductor, so that the magnetic lines of force of the field are cut

A

Magnetism

71
Q

All voltage sources share the characteristic of ______

A

An excess of electrons at one terminal and a shortage of electrons at the other terminal

72
Q

Material impedes the flow of electrical current to some extent. This characteristic is called ____

A

Resistance

73
Q

Resistance in a conductor increases with _____, or a decrease of ______

A

Length Cross section

74
Q

Unit of measurement for resistance

A

Ohms

75
Q

Unit abbreviation for ohms

A

Omega

76
Q

In mathematical equations ohms is represented by ____

A

R

77
Q

Resistance is usually indicated symbolically on an electrical drawing by

A

An unfilled rectangle or a zig zag line

78
Q

Current varies directly with voltage and inversely with resistance

A

Ohm’s law

79
Q

The rate at which work is done

A

Power

80
Q

Power is represented by the symbol ____

A

P

81
Q

Power is represented in _____

A

Watts

82
Q

Watts are represented by the symbol ____

A

W

83
Q

The rate work is done in a circuit when one amp flows with one volt applied

A

Watt

84
Q

Electrical equipment is rated in ____

A

Watts

85
Q

An indication of the rate at which electrical equipment converts electrical energy into other forms of energy

A

Wattage rating

86
Q

Consists of a voltage source with a positive and a negative terminal, some type of load providing resistance, and a conductor allowing electrons to flow between the voltage source and the load, with a complete path for current to flow

A

Simple electrical circuit

87
Q

Has only one path of current flow

A

Series circuit

88
Q

More than one path of flow for electrical current

A

Parallel circuit

89
Q

Circuit in which the electricity has found an alternative path to return to the source without going through an appropriate load

A

Short circuit

90
Q

Conductor that is intentionally grounded to earth at the power supply

A

Grounded conductor

91
Q

This conductor is called the neutral wire and is identified with the color white or gray

A

Grounded conductor

92
Q

Occurs when there is an accidental path of low resistance between the electrical conductor and earthen ground

A

Ground fault

93
Q

Three basic properties of components used in electronic circuits

A

Resistance, capacitance, inductance

94
Q

The property of a component to oppose the flow of electrical current through itself

A

Resistance

95
Q

The property of a component to oppose any change in voltage across its terminals, by storing and releasing energy in an internal electric field

A

Capacitance

96
Q

The property of a component to oppose any change in current through itself, by storing and releasing energy in a magnetic field surrounding itself

A

Inductance

97
Q

Components that are used to control the amount of current flowing in a circuit

A

Resistor

98
Q

Also known as a condenser, is a device that stores energy in an electric field, by accumulating an internal imbalance of electric charge

A

Capacitor

99
Q

Consists of two conducting plates separated by an insulating material called dielectric

A

Capacitor

100
Q

Directly proportional to the surface areas of the plates, and is inversely proportional to the separation between the plates

A

Capacitance

101
Q

Standard unit of measure for capacitance

A

FARAD

102
Q

Unit abbreviation for a FARAD

A

F

103
Q

An electronic component that stores energy in the form of a magnetic field and consists of a wire loop or coil

A

Inductor

104
Q

As current flows through the wire, a magnetic field is generated; this is known as ____

A

Electromagnetism

105
Q

Increasing current flowing through the wire causes voltage to be produced by the magnetic field, which opposes the change in current; this is known as _____

A

Inductance

106
Q

Directly proportional to the number of turns in the coil, also depends on the radius of the coil and on the type of material around which the coil is wound

A

Inductance

107
Q

Standard unit of measure for inductance

A

HENRY

108
Q

Unit abbreviation for HENRY

A

H

109
Q

Schematic symbol for HENRY

A

L

110
Q

The force where objects are attracted or repelled to one another, due to the motion of electric charges

A

Magnetism

111
Q

Invisible magnetic lines of force, leave the north pole and enter the south pole of a magnet

A

Flux

112
Q

Continuous, always forming complete loops, never crossing one another, and passing through all materials both magnetic and non-magnetic

A

Magnetic lines of force

113
Q

Space around a magnet in which these lines of force may be detected

A

Magnetic field

114
Q

Produced whenever there is an electrical charge in motion

A

Magnetic field

115
Q

Production of a magnetic field by current flowing in a conductor

A

Electromagnetism

116
Q

Produces an electromotive force (emf) or voltage, which in turn produces a current

A

Magnetic field

117
Q

Process of generating current in a conductor by placing the conductor in a changing magnetic field

A

Induction

118
Q

For electromagnetic induction to take place, the conductor must be _____

A

Perpendicular to the magnetic lines of force, or else no voltage will be induced

119
Q

Determined by the direction of the lines of force and by the direction the wire is moving in the field

A

Direction that the induced current flows

120
Q

A coil of wire spun in a magnetic field at a constant rate will produce ___

A

AC electricity

121
Q

Most versatile meter

A

Multimeter

122
Q

Measures current

A

Ammeter

123
Q

Measures the potential difference (voltage) between two points

A

Voltmeter

124
Q

Measures resistance

A

Ohmmeter

125
Q

Comprised of a display, function switch, connection terminals, and range button

A

Fluke digital multimeter

126
Q

Useful in locating defective circuits and components during corrective maintenance

A

Resistance measurements

127
Q

When measuring voltage, connect the meter leads in _____ the voltage to be tested

A

Parallel (or across)

128
Q

Measuring resistance, k = reading x _____

A

1000

129
Q

Resistance measurement, M = reading x _____

A

1000000

130
Q

Device that measures current

A

Ammeter

131
Q

The multimeter must be wired in _____ with the loads in order to monitor the current

A

Series

132
Q

Has a hook that is clamped around a conductor and detects the rising and falling magnetic field

A

Clamp-on ammeter

133
Q

The Amprobe AC/DC 600A can test up to ____

A

600 amps AC and DC

134
Q

To check circuit current flow, the circuit must be ____

A

Energized

135
Q

Two instruments most commonly used to measure resistance of a circuit

A

Ohmmeter and the megohmmeter

136
Q

Cannot be used for measuring resistance of multimillions of ohms such as in conductor insulation

A

Ordinary ohmmeter

137
Q

Used to measure very high resistance values such as those found in cable insulation and motor and transformer windings

A

Megohmmeter

138
Q

Uses a relatively high voltage (500V - 1000V) in order to determine resistance in mega ohms

A

Megger

139
Q

Which meter provides the most adequate test for insulation breakdown

A

Megohmmeter

140
Q

What is the advantage of clamp on ammeter versus the multimeter type of ammeter

A

Not limited by test leads

141
Q

Term used for an electrical current that moves only in one direction

A

Direct current

142
Q

Occurs when the polarity and output voltage from a power source never change direction

A

DC

143
Q

Converts mechanical energy into electrical energy

A

Charging circuit

144
Q

Typical charging circuit consists of ____

A

Battery, alternator, voltage regulator

145
Q

Provides for general, detail, special, low level, and emergency illumination

A

Lighting circuit

146
Q

Used to alert the crew whenever there is a deviation from the engine’s normal operating parameters

A

Engine alarm circuit

147
Q

The equipment used to steer a ship or boat on the operator’s desired course

A

Steering circuit

148
Q

_____ pressure sensor output is normally around 30mV and directly proportional to the pressure sensor input power or excitation

A

Millivolt

149
Q

____ power supplies are suggested for use with millivolt sensors

A

Regulated

150
Q

_____ pressure sensor output is normally 0 - 5 VDC or 0 - 10 VDC, and the output of the sensor is not normally a direct function of excitation

A

Volt

151
Q

This pressure sensor is not as susceptible to electrical noise and can be used in more industrial environments

A

Volt pressure sensor

152
Q

4 - 20 mA pressure sensor

A

Pressure transmitter

153
Q

Pressure transmitter commonly found in applications where the lead wire must be ____ or more

A

1000 feet

154
Q

Used to monitor the speed of rotation for components

A

Speed sensor

155
Q

Consist of a coil wrapped around a magnet and located near a gear wheel

A

Magnetic speed sensor

156
Q

Frequently used as switches or controls for mechanical devices such as valves

A

Solenoids

157
Q

Consists of a wire coil and a movable plunger that rests next to the coil

A

Solenoid

158
Q

Device that usually moves or controls equipment to give a change in position or direction

A

Actuator

159
Q

Two common methods for isolating a problem within a system

A

Half-split and section-by-section

160
Q

The half-split method works best on ____

A

Large systems

161
Q

The section-by-section method works best on ___

A

A smaller system such as a small portion of a large system

162
Q

What two types of checks are performed for troubleshooting

A

Visual and operational

163
Q

How can components be isolated from wiring and other components

A

Tripping a breaker, opening a switch, or disconnecting the component

164
Q

Why is additional test equipment needed when testing pressure and temperature switches or sensors

A

To simulate pressure or temperature

165
Q

Hazards posed by batteries

A

Electrical shock, acid burns, explosion, release of hazardous gases

166
Q

This is produced while charging batteries

A

Hydrogen sulfide

167
Q

Lower the charging rate as soon as the battery begins to gas or the temperature reaches ____

A

125*F

168
Q

Keep the temperature of the battery compartment below ____

A

96*F

169
Q

Make no repairs to battery when ____

A

Current is flowing

170
Q

In a battery, always pour ___ slowly into ____, never the other way around

A

Acid into water

171
Q

If eyes contact acid, flush them for how long

A

Minimum 15 minutes

172
Q

Do not add acid of greater specific gravity than ___ to a battery

A

1.350

173
Q

Do not store sulfuric acid where

A

Freezing temperatures are possible

174
Q

Keep the electrolyte level ____ above the tops of the separators

A

3/8”

175
Q

Never allow a battery to stand in a completely discharged condition for more than ____

A

24 hours

176
Q

Never operate a battery above _____

A

125*F

177
Q

Device that transforms chemical energy into electrical energy via an electrochemical process or chemical reaction that produces electrons

A

Battery

178
Q

Consists of two or more cells assembled in a common container and connected together to function as a source of electrical power

A

Battery

179
Q

Consists of two strips of dissimilar metals, or electrodes, placed in a container with a solution known as electrolyte, a nonmetallic conductor

A

Simple cell

180
Q

The conductors by which the current leaves or returns to the electrolyte

A

Electrodes

181
Q

Solution that acts upon the electrodes and provide a path for electron flow (internal resistance)

A

Electrolyte

182
Q

Commonly comprised of sulfuric acid and distilled water, but may be salt, an acid, or an alkaline solution

A

Electrolyte

183
Q

Energy is derived from an essentially irreversible electrochemical reaction; cannot be efficiently recharged; and is discarded following discharge

A

Primary cell battery

184
Q

Primary cell battery also called

A

Dry cell

185
Q

Secondary cell battery is also called

A

Wet cell

186
Q

The electrodes and the electrolyte are altered by the chemical action that takes place when the cell delivers current. These cells may be restored to their original condition by forcing an electric current through them in the direction opposite to that of discharge

A

Secondary cell battery

187
Q

Secondary cell batteries are commonly known as

A

Storage batteries

188
Q

Voltage source that uses chemical action to produce a voltage

A

Battery

189
Q

Batteries connected in parallel provide higher

A

Current capacity

190
Q

Batteries connected in series provide

A

A higher voltage

191
Q

Used to remove corrosion and dirt from battery terminals and cable clamps

A

Battery brush

192
Q

Side terminal brush

A

Used to clean corrosion from side post batteries

193
Q

Used to remove the battery terminal clamp without damaging the battery post

A

Battery terminal puller

194
Q

Used to clean and spread battery terminal cables

A

Battery terminal spreader and cleaner

195
Q

Used to add water or electrolyte to the battery

A

Battery filler

196
Q

The electrolyte level shall be inspected how often

A

Once a week or more

197
Q

First step in installing a battery

A

Determine the polarity of terminals

198
Q

Ratio of the weight of a certain volume of liquid to the weight of the same volume of water

A

Specific gravity

199
Q

Specific gravity of electrolyte in a battery gradually ____ on discharge

A

Decreases

200
Q

Glass barrel fitted with a rubber nozzle at one end which may be dipped into the electrolyte of a cell without risking damage to the separators

A

Battery hydrometer

201
Q

For most batteries the float should be graduated to cover specific gravities in the range of ____

A

1.100 - 1.300

202
Q

In a new battery, the specific gravity should read

A

1.260 - 1.300

203
Q

Fully charged battery hydrometer reading

A

1.260

204
Q

75% charged battery hydrometer reading

A

1.250

205
Q

50% charged battery hydrometer reading

A

1.220

206
Q

25% charged battery hydrometer reading

A

1.190

207
Q

Discharged battery hydrometer reading

A

1.130

208
Q

Normal temperature to which specific gravity readings are corrected

A

80*F

209
Q

How many points to add to each reading for each 10*F above 80*F

A

4

210
Q

Fast and easy-to-use method for testing battery charge condition and for testing the freezing point of glycol based antifreeze

A

Refractometer

211
Q

The glycol and battery tester is available in two models

A

7084VP for testing in Fahrenheit, and 7064VP for testing in Celsius

212
Q

The coolant reading is on the ____, battery charge is on the _____ (refractometer)

A

Right, left

213
Q

Rate at which electron flow is forced into the battery

A

Charging rate of a battery

214
Q

Safest charging rate

A

Below 10 amperes

215
Q

Four types of charges that may be given to a storage battery

A

Initial, normal, equalizing/boost, floating

216
Q

A normal charge is complete when the specific gravity of the pilot cell, corrected for temperature, is within ___ of the specific gravity obtained on the previous charge

A

5 points

217
Q

Randomly selected cells located in the center of each battery system used to monitor temperature and specific gravity

A

Pilot cells

218
Q

For additional information on the selection of pilot cells, see

A

NSTM, chapter 313, 313-2.3.3, numbering batteries

219
Q

During a normal charging procedure, check the temperature and specific gravity how often

A

Every hour

220
Q

During a normal charging procedure, do not allow the temperature of the electrolyte of exceed

A

52*C, 125*F

221
Q

Extended normal charge at the finishing rate

A

Equalizing/boost charge

222
Q

When the battery is held at a specific voltage that is well below its gassing point until fully charged

A

Floating charge

223
Q

Typical float charge for a 12-volt, lead acid battery

A

13.1 volts

224
Q

Best method to check battery condition

A

Battery load tester, also called battery capacity test

225
Q

Measures the current output and performance of the battery under full load

A

Battery load test

226
Q

Evaluates the batteries ability to supply sufficient current to the standby supply or other electronic device

A

Battery load tester

227
Q

To test, battery terminal voltage must be

A

12.60V or greater

228
Q

Number of amperes a lead-acid battery at 0*F (-17*C) can deliver for 30 seconds and maintain for at least 1.2 volts per cell (7.2 volts for a 12 volt battery)

A

Cold cranking amperage

229
Q

Tools used to diagnose engine start systems

A

Battery analyzers

230
Q

Use conductance technology instead of load test

A

Battery analyzers

231
Q

Slender rod or filament of drawn metal

A

Wire

232
Q

Measures diameter of conductor

A

Wire gauge

233
Q

What to consider when choosing a wire gauge

A

The distance it will run and the amperage it will be expected to carry

234
Q

First step in making a splice

A

Stripping or removing insulation from the wire

235
Q

Strippers will only strip how much insulation at a time

A

3/4”

236
Q

Most common connectors used for splicing or connecting electrical wires

A

Wire nut, split bolt splice, pre-insulated terminal lug, pre-insulated splice

237
Q

Device commonly used to replace the rattail joint splice, should be considered temporary in marine applications

A

Wire nut

238
Q

Housed in plastic insulating material, place two stripped conductors in and twist

A

Wire nut

239
Q

Often used to join large conductors and can be used to replace the knotted tap joint

A

Split bolt splice

240
Q

Small diameter copper wires are terminated with solderless ____

A

Pre-insulated terminal lug

241
Q

Used to join small copper wire AWG sizes no. 26 through no. 10

A

Pre-insulated splices

242
Q

Yellow (bright) terminal lug or splice insulation is used on sizes

A

26 - 24

243
Q

Red terminal lug or splice insulation is used on sizes

A

22 - 20, 18

244
Q

Blue terminal lug or splice insulation is used on sizes

A

16 - 14

245
Q

Yellow (dull) terminal lug or splice insulation is used on sizes

A

12 - 10

246
Q

Final step in completing a splice or connection

A

Placing insulation over the splice

247
Q

Five common insulators used for splicing

A

Heat shrinkable tubing, rubber tape, friction tape, electrical tape, electrical coating

248
Q

Most common form of insulator used for terminals

A

Heat shrinkable tubing

249
Q

Heat shrinkable tubing shrinks how much when heated

A

One half its original diameter

250
Q

When using heat shrinkable tubing, hold the heat source how far away

A

4 - 5 inches

251
Q

When using heat shrinkable tubing, apply heat of how much for how long

A

275*F to 300*F for 30 seconds

252
Q

After heating heat shrinkable tubing, let it cool for how long before handling

A

30 seconds

253
Q

Splicing compound used when the original compound is rubber

A

Rubber tape

254
Q

Cotton cloth that has been treated with a sticky rubber compound, is used to restore the protective covering and provide some electrical insulation

A

Friction tape

255
Q

Commonly used to repair and protect bare wires, can withstand higher voltages for a given thickness

A

Electrical tape

256
Q

Fast drying sealant and bonding agent recommended for splices wrapped with tape

A

Electrical coating

257
Q

Electrical flow in which the current flows first in one direction until the voltage reaches the peak desired value, then reverses its flow until the peak desired value is reached in the opposite direction

A

Alternating current

258
Q

AC generator converts mechanical energy into electrical energy by utilizing the principle of

A

Electromagnetic induction

259
Q

Generator converts energy by

A

Producing currents in conductors rotated in a magnetic field

260
Q

Graphic representation for AC

A

Sine wave

261
Q

A sine wave can represent

A

Current or voltage

262
Q

A sine wave moves through a rotation of

A

360 degrees

263
Q

A sine wave moving through one complete rotation is known as

A

A cycle

264
Q

Unit of measurement for cycles per second

A

Hertz (Hz)

265
Q

Consists of a permanent magnet, an armature, slip rings, brushes, and a conductor loop

A

Elementary AC generator

266
Q

After the loop has rotated ____, the current direction switches

A

180 degrees

267
Q

Collect the current from the slip rings and transfer the current via an external circuit

A

Conducting brushes

268
Q

Number of cycles per second made by voltage induced in the armature

A

Frequency of the generator

269
Q

Fast drying sealant and bonding agent recommended for splices wrapped with tape

A

Electrical coating

270
Q

Electrical flow in which the current flows first in one direction until the voltage reaches the peak desired value, then reverses its flow until the peak desired value is reached in the opposite direction

A

Alternating current

271
Q

AC generator converts mechanical energy into electrical energy by utilizing the principle of

A

Electromagnetic induction

272
Q

Generator converts energy by

A

Producing currents in conductors rotated in a magnetic field

273
Q

Graphic representation for AC

A

Sine wave

274
Q

A sine wave can represent

A

Current or voltage

275
Q

A sine wave moves through a rotation of

A

360 degrees

276
Q

A sine wave moving through one complete rotation is known as

A

A cycle

277
Q

Unit of measurement for cycles per second

A

Hertz (Hz)

278
Q

Consists of a permanent magnet, an armature, slip rings, brushes, and a conductor loop

A

Elementary AC generator

279
Q

After the loop has rotated ____, the current direction switches

A

180 degrees

280
Q

Collect the current from the slip rings and transfer the current via an external circuit

A

Conducting brushes

281
Q

The frequency is the same as

A

The number of rotations per second

282
Q

AC circuit has two characteristics

A

Voltage and current

283
Q

When two waveforms are in step with each other

A

In phase

284
Q

When the circuit is a resistive circuit, the voltage and the current will be

A

In phase

285
Q

When the circuit contains an inductive load, the relationship will be

A

Forced out of phase

286
Q

When two waveforms are out of phase, the relationship between the two is called

A

Lead or lag

287
Q

Phase differences are expressed in

A

Degrees

288
Q

AC is divided into

A

Single phase, and three phase types

289
Q

Used for small electrical demands as found in the home

A

Single phase power

290
Q

Made up of a number of windings (coiled conductor) connected in series, forming a single circuit

A

Single phase generator

291
Q

This voltage is represented by a singe waveform

A

Single phase power

292
Q

Continuous series of three overlapping AC cycles and is used where large blocks of power are required such as in commercial applications and industrial plants

A

Three phase power

293
Q

Has three single phase windings which create three separate circuits

A

Three phase AC generator

294
Q

Three phase AC generator windings are ____ out of phase with the voltages in the other two windings

A

120 degrees

295
Q

Three phase power is represented by

A

Three waveforms

296
Q

One of the most common loads on any electrical system

A

Electric motor

297
Q

Device which converts electrical energy (current) into mechanical work (motion)

A

Motor

298
Q

Typical motors are powered by

A

120V, 240V, or 480V supplies

299
Q

Comprised of a fixed outer portion called the stator, and a revolving inert portion called a rotor

A

AC motor

300
Q

Made up of a hollow cylinder or core with slots

A

Stator

301
Q

The type of motor is determined by

A

The number of windings and their configuration

302
Q

Two types of rotors

A

Cage rotor, wound rotor

303
Q

Have a laminated cylindrical core with parallel slots in the outside circumference to hold the windings in place

A

Rotor

304
Q

This rotor has an uninsulated bar winding

A

Cage rotor

305
Q

This rotor has a two layer distributed winding with preformed coils

A

Wound rotor

306
Q

AC motors are classified by

A

The type of AC power they use to operate

307
Q

Require additional power in order to produce a rotating magnetic field

A

Single phase motors

308
Q

Incoming power produces a rotating magnetic current on its own, allowing this motor to be self starting

A

Three phase motor

309
Q

AC motors can be divided into the following types

A

Series, synchronous, and induction

310
Q

Have field poles wired in series with the rotor

A

Series type motors

311
Q

Needs brushes to ride on a communicator, a pair of rings attached to the shaft of the rotor, to provide the connection between the poles and the rotor

A

Series type motor

312
Q

A series motor is also called

A

A universal rotor because it can be hooked up to AC or DC voltage

313
Q

Specifically designed to maintain constant speed with the rotor, synchronous to the rotating field

A

Synchronous motor

314
Q

This motor requires modification to be self starting

A

Synchronous motor

315
Q

Have a rotor turned by induction from the stator

A

Induction motor

316
Q

Most commonly used AC motor

A

Induction motor

317
Q

1HP =

A

746 Watts

318
Q

Voltage on a motor must be maintained ____ for reliable operation

A

Plus or minus 10%

319
Q

Motor must always maintain ___ of rated frequency to prevent damage

A

Plus or minus 5%

320
Q

Insulation temperatures are represented in

A

Degrees Celsius

321
Q

To convert Celsius to Fahrenheit

A

x 1.8 + 32

322
Q

To convert Fahrenheit to Celsius

A

-32 x .555

323
Q

Motor windings can be tested for the following faults

A

Open winding, shorted winding, ground

324
Q

Motor windings should be tested when

A

Immediately following shutdown when the motor windings are still hot and dry

325
Q

Result of a burned wire in the winding or a break somewhere in the winding that prevents the current from completing the circuit

A

Open winding

326
Q

Motor with this will not start

A

Open winding

327
Q

Result of two windings making contact

A

Shorted winding

328
Q

Will eventually result in an open winding

A

Shorted winding

329
Q

Result of an electrical conductor in contact, either directly or indirectly, with the motor frame or the metal shell of the unit

A

Ground

330
Q

A ground is either

A

One of low resistance or high resistance

331
Q

Indicated when fuses blow repeatedly and the motor fails to start

A

Low resistance ground

332
Q

Indicated by an occasional blown fuse, but more often by the opening of the overload protector

A

High resistance ground

333
Q

This fault can lead to a serious shock hazard

A

Ground

334
Q

When testing motor windings for ground using a megohmmeter disconnect

A

The motor leads from each other to ensure the readings are indicated only one winding at a time

335
Q

Mounted externally to the engine and are used to circulate the coolant through the water jacket

A

Engine heaters

336
Q

Occurs when a gas or liquid is heated by some external means, causing the lighter heated gas or liquid to rise

A

Thermo-siphon

337
Q

This process can be used to move heated air or water through a system without externally powered pumps or fans

A

Thermo-siphon

338
Q

Under normal conditions, all the coolant in the engine will pass through the heater how often

A

Three or four times an hour

339
Q

Two main benefits of using an engine heater

A

Easier starts and reduced engine wear

340
Q

Two pieces of metal that touch to make a circuit and separate to break the circuit

A

Contacts

341
Q

Switches are classified according to

A

The arrangement of their contacts

342
Q

Set of contacts that belong to a single circuit

A

Pole

343
Q

One of two or more positions that the switch can adopt

A

Throw

344
Q

Actuated by gas or liquid pressure in a piston, diaphragm, or bellows, and converts pressure to mechanical force

A

Pressure switch

345
Q

Protective device inserted in series with a circuit containing a metal that will melt or break when current is increased beyond a specific value for a definite period of time

A

Fuse

346
Q

Three types of fuses

A

Plug, ribbon, knife

347
Q

Designed to break the circuit and stop the current flow when the current exceeds a predetermined value

A

Circuit breaker

348
Q

Commonly used in place of a fuse and may eliminate the need for a switch

A

Circuit breaker

349
Q

Two common types of circuit breakers

A

Thermal, magnetic

350
Q

Seven common types of drawings

A

Pictoral Isometric Block Single-line Terminal Schematic Wiring

351
Q

Simplest of all diagrams

A

Pictoral

352
Q

Shows a picture or sketch of the components of a specific system and the wiring between these components

A

Pictoral

353
Q

This type of diagram provides a means to recognize the physical appearance of each component and its interconnections with the other components of the system

A

Pictoral

354
Q

Shows the sequence in which the components are connected without regard to their physical location, how the wiring is marked, or how the wiring is routed

A

Pictoral diagram

355
Q

Purpose of this diagram is to assist you in locating a component within a system

A

Isometric diagram

356
Q

Shows the major components of a system and the interconnections of these components, and is often used with accompanying text material

A

Block diagram

357
Q

Used basically for the same purpose as the block diagram. When used with text material, it provides you with a basic understanding of the components and their functions in a system

A

Single-line diagram

358
Q

Two major differences between single line diagram and block diagram

A

Single line uses symbols rather than labeled blocks, and all components are show on a single line with no interconnections

359
Q

Useful when connecting wires to terminal boards, relays, switches, or other components of a circuit

A

Terminal diagram

360
Q

Two types of terminal diagrams

A

Terminal board diagram Relay terminal diagram

361
Q

Most commonly used diagrams

A

Schematic and wiring

362
Q

Emphasize connections between elements of a circuit or system

A

Wiring diagram

363
Q

Use horizontal and vertical lines to represent wires

A

Wiring diagram

364
Q

Use simplified pictorials that clearly resemble circuit/system components

A

Wiring diagram

365
Q

Place equipment and wiring on drawing to approximate actual physical location in real circuit

A

Wiring diagram

366
Q

Emphasize flow of system

A

Schematic diagram

367
Q

Use horizontal and vertical lines to show system flow

A

Schematic diagram

368
Q

Use symbols that indicate function of equipment, but the symbols do not look like the actual equipment

A

Schematic diagram

369
Q

Drawing layout is done to show the flow of the system as it functions, not the physical layout of the equipment

A

Schematic diagram

370
Q

Uses graphic symbols to show both the electrical components and the functional organization of a circuit

A

Schematic diagram

371
Q

This diagram should be used to determine the location where the trouble in the circuit could be when a malfunction occurs

A

Schematic diagram

372
Q

Shows all wiring, connectors, terminal boards, and electrical or electronic components of a circuit

A

Wiring diagram

373
Q

May identify wire-by-wire number or color code

A

Wiring diagram

374
Q

This diagram should be used to troubleshoot and repair electrical or electronic circuits

A

Wiring diagram

375
Q

Can be used to determine where to make the voltage or resistance checks in the circuit

A

Circuit-wiring diagram

376
Q

To read electrical diagrams and schematics properly, what must first be understood

A

The condition or state of each component

377
Q

To associate the proper relay with the contacts that it operates, each relay is assigned

A

A specific number and/or letter combination

378
Q

The position of one internal switch will affect the position of another

A

Ganged switches

379
Q

Ganged switches are shown symbolically by

A

Connecting them with a dashed line

380
Q

Used to indicate a mechanical interlock between two circuit components

A

Dashed line

381
Q

Wires that are connected are usually depicted on a diagram with what at the point where the wires join

A

Dot

382
Q

Wires that cross but do not join are depicted by

A

A hump

383
Q

Never operate any personal electronic equipment without the authorization of who

A

XO EO

384
Q

What level of shock from a 60-Hz AC system can be fatal if it lasts for one second or more

A

100 milliamperes (0.1 A)

385
Q

What firefighting agent is not recommended for electrical fires because it causes corrosion of electrical and electronic components

A

Potassium bicarbonate (PKP)

386
Q

When at sea, what is more fatal and damaging to both personnel and the ship itself than damage from battle

A

Fire