Electricity Flashcards
(181 cards)
1
Q
What statement is true concerning the electrical diagram shown in figure “B” of the illustration? Illustration EL-0019
A
“R1”, “R2”, and “R3” are connected in parallel.
2
Q
In a series circuit, which value will remain unchanged at all places in the circuit?
A
Current
3
Q
As shown in figure “A” of the illustrated block diagram of a central operating system configured for direct digital control, what does the output system block “ANALOG D/A” represent? Illustration EL- 0095
A
It receives digital outputs from the CPU and converts these to analog signals for transmission to the analog actuators.
4
Q
With an accidental ground on leg C as shown in figure “C” of the illustration, what would be the indication? EL-0008
A
Lamp L would be bright due to unbalanced voltages across the transformer secondary’s
5
Q
A hydrometer measures specific gravity by comparing the __________.
A
buoyancy of an indicator in water with the buoyancy of the same indicator in the liquid being measured
6
Q
What is the ampere-hour rating of a lead-acid battery that can deliver 20 amperes continuously for 10 hours?
A
200
7
Q
As the electrolyte level in the cells of a lead-acid battery evaporates over time, what will tend to happen to the specific gravity of the electrolyte in the cells as the level drops due to evaporation?
A
The specific gravity of the electrolyte will increase as only the water will evaporate from the electrolyte solution.
8
Q
In a series circuit, which value will remain unchanged at all places in the circuit?
A
Current
9
Q
Which statement is true concerning the total power consumed in a parallel circuit?
A
The total power is equal to the sum of the powers consumed by each individual load.
10
Q
s shown in the illustration, the wet-cell storage batteries are connected in what configuration? EL-0071
A
series
11
Q
The individual 6 volt lead-acid batteries, when connected as shown in the illustration, as a battery bank would produce how many volts? Illustration EL-0070
A
6 volts
12
Q
What would be the terminal voltage and ampere-hour capacity of the battery bank if each battery was rated at 50 amp-hours and 6 volts? Illustration EL-0107
A
12 volts and 100 ampere-hours
13
Q
In the illustration, 1, 2, 3 and 4 are 12 volt batteries. What will be the nominal voltage as read by a voltmeter across the output of the battery bank? Illustration EL-0107
A
24 volts
14
Q
What would be the terminal voltage and ampere-hour capacity of the battery bank
illustrated if each battery was rated at 75 ampere-hours and 12 volts? EL-0107
A
24 volts and 150 ampere-hours
15
Q
The wet-cell storage batteries shown in the illustration are connected in what configuration? Illustration EL-0070
A
parallel
16
Q
The individual 12 volt lead-acid batteries, when connected as shown in the illustration, as a battery bank would produce how many volts? EL-0070
A
12 volts
17
Q
In the illustrated views of a lead acid battery as shown in figures “A” and “B”, what battery component has the sole function of preventing the individual plates in the negative plate group from coming into direct contact with the individual plates in the positive plate group? Illustration EL-0031
A
separators
18
Q
As shown in the cutaway view of the lead acid battery in figure “A” of the illustration, if one half of the battery’s cells are revealed by the cutaway section (with the other half remaining hidden from view), what is the nominal output voltage of the battery? EL-0031
A
12 volts
19
Q
If the circuit shown in the illustration were energized and operating properly, which of the devices listed would be open? Illustration EL-0007
A
The start push-button
20
Q
The illustrated motor fails to start and gives a loud hum when the start button is depressed, what should then be your first action? Illustration EL-0007
A
push the stop button to deenergize the “M” coil
21
Q
Which of the electronic schematic symbols represents the capacitor illustrated in figure 2 of the illustration? Illustration EL-0015
A
C
22
Q
Which of the electronic schematic symbols represents the capacitor illustrated in figure 1 of the illustration? Illustration EL-0015
A
B
23
Q
Which of the illustrated resistors represents the schematic symbol shown in figure “C”? Illustration EL-0021
A
figure “6”
24
Q
As shown in figure “6” of the illustration, what does the symbol represent as used in electrical drawings? Illustration EL-0026
A
maintaining type push button with a mechanical interlock
25
Which of the illustrated schematic symbols represents the type of switch pictured in figure "F" of the illustration? Illustration EL-0026
3
26
Which of the following statements concerning figure "6" of the illustration is true? EL-0026
The symbol represents a switch using maintained contact with "either/or" logic.
27
In figure "1" of the illustration, what are the trip characteristics associated with this type of circuit breaker? Illustration EL-0033
inverse-time delay characteristic for sustained overloads
28
In figure "A" of the illustration, what is the position of the circuit breaker? Illustration EL-0033
off
29
In the illustration what is the component labeled "C"? EL-0033
fixed contact
30
Which figure represents the schematic symbol shown in figure "2"? Illustration EL-0034
figure "B"
31
What is the resistance reading at "2" on the megger scale shown in figure "A" of the illustration? Illustration EL-0044
40 megohms
32
As shown in figure "A" of the illustrated digital multimeter screen, what would be the significance of the symbol indicated by "2" being illuminated? Illustration EL-0047
the selector switch is in the continuity/diode test position and the secondary function pushbutton is toggled for diode
33
As shown in figures "B" and "C" of the illustration, what should be the switch position and which test lead terminal jacks should be used if your intent is to measure DC currents anticipated as high as 200 milliamps? Illustration EL-0047
switch position "6" and terminal jacks "1 and 4"
34
As shown in figure "A" of the digital multimeter screen shown in the illustration, what would be the significance of the symbol indicated by "1" being illuminated? EL-0047
the selector switch is selected for continuity/diode test and the secondary function pushbutton
is toggled for continuity
35
A load is connected across the secondary of the step up transformer shown in figure "B" of the illustration and the current drawn by the load is 10 amps. If the turns ratio is 1 to 10 and the input voltage is 110 VAC, what will be the current drawn by the primary? Illustration EL-0055
100 amps
36
Which of the listed figures in the illustration represents a transformer configured for single voltage primary and a tapped secondary? Illustration EL-0055
D
37
If the illustrated device in figure "B" has a step-up ratio of 10 to 1 what voltage would be measured at the secondary shortly after the primary of the device is connected to 110 volts DC with a current of 12 amps? Illustration EL-0055
0 volts
38
Which electrical schematic symbol represents a normally open thermostat? Illustration EL-0059
9
39
Which of the electrical schematic symbols represents a normally open limit switch? Illustration EL-0059
12
40
Which electrical schematic symbol shown in the illustration represents a normally closed thermostat? EL-0059
8
41
Which of the electrical schematic symbols shown in the illustration represents a normally closed limit switch? EL-0059
11
42
In electrical circuit schematics, a normally open pressure switch is represented by which of the symbols shown in the illustration? EL-0059
2
43
A load is connected across the secondary of the step up transformer shown in figure "B" of the illustration and the current drawn by the load is 10 amps. If the turns ratio is 1 to 10 and the input voltage is 110 VAC, what will be the current drawn by the primary? Illustration EL-0055
100 amps
44
Which of the listed figures in the illustration represents a transformer configured for single voltage primary and a tapped secondary? Illustration EL-0055
D
45
What is the most reliable and preferred method for determining the state of charge of a wet-cell NiCad battery?
Measuring the battery voltage with a digital voltmeter during charge or discharge.
46
Which of the pictured solid-state semiconductor devices in the illustration is a rectifier bridge? Illustration EL-0068
3
47
What is the name of the device shown in figure "2" of the illustration? Illustration EL-0068
power rectifier diode
48
Which of the pictured solid state semiconductor devices is a light-emitting diode? EL- 0068
7
49
The turns ratio of the tapped step down transformer shown in figure "C" of the illustration is four to one and all taps are equally spaced. If 440 volts were applied between 'H1' and 'H4', what would appear across 'X1' and 'X4'? EL-0082
110 volts
50
The transformer diagram shown in figure "B" of the illustration represents what type of transformer? EL-0082
step down transformer with dual voltage secondary
51
The turns ratio of the step down transformer with dual voltage secondary shown in figure "B" of the illustration is two to one (total). If 220 volts were applied to terminals 'H1' and 'H2', what would be measured across 'X3' and 'X4'? EL-0082
55 volts
52
The turns ratio of the step down transformer with dual voltage secondary as shown in figure "B" of the illustration is two to one (total). If 440 volts were applied to terminals 'H1' and 'H2', what would be measured across 'X1-X3' and 'X2-X4' assuming that the secondary windings are connected in parallel? Illustration EL-0082
110 volts
53
What would be the source current and transformer current as shown in figure "B" of the illustration, with the secondary tap connected as shown, if the supply voltage at the branch circuit breaker is 440 VAC and the unity power factor load current draw is 50 amps? Illustration EL-0083
source current is 12.5 amps, transformer current is 37.5 amps.
54
Assuming that 450 VAC is the source voltage at the circuit breaker, if 450 volts AC were measured across the load as shown in the illustration as shown in figure "B" of the illustration, what would this indicate? EL-0083
an open winding between the reference point "X" and the 25% tap connection
55
As shown in figure "B" of the illustration, if the source voltage at the branch circuit
breaker is 220 VAC, what would be the applied voltage to the load? EL-0083
55 volts
56
Which of the listed figures shown in the illustration represents a three phase transformer connected in a wye-delta configuration? Illustration EL-0084
4
57
In figure "1" of the diagram shown in the illustration, the three phase step down power transformer has a turns ratio of four to one. If a three-phase 440 volt supply is connected to terminals "A1-B1-C1", what voltage should develop across terminals "A2-B2-C2"? EL-0084
110 volts
58
Which of the listed figures shown in the illustration represents a three phase transformer connected in a wye-wye configuration? EL-0084
2
59
In figure "4" of the diagram in the illustration, the three phase step down power transformer has a turns ratio of five to one. If a three-phase 4160 volt supply is connected to terminals "A1-B1-B2", what voltage should develop across terminals "A2- B2-C2"? Illustration EL- 0084
480 volts
60
A carbon resistor has a resistance of 50 ohms, and a tolerance of 5 percent. What would be the respective colors indicated for bands 1, 2, 3 and 4 for this resistor as shown in figure "A" of the illustration? EL-0103
green, black, black, and gold.
61
In referring to the illustration of the elementary DC generator, what statement is true? (EL-0028)
In a complete revolution of the armature, the current flow direction within the armature winding does reverse, whereas the current flow direction in the external load does not reverse.
62
What is statement is true in reference to reading electrical motor controller elementary diagrams?
current paths in the power circuit are drawn as heavy lines and in control circuit as lighter lines
63
In a conventional AC generator utilizing brushes, direct current from the exciter output is passed through the windings of the main field rotor by what means?
by means of slip rings
64
What may cause brush sparking in a DC generator during commutation?
misalignment of the brush rigging
65
What is the function of the interpoles installed in DC motors?
To provide sparkless commutation without having to shift the brushes.
66
Which of the listed colors properly describes a DC motor commutator when correct
commutation is taking place?
Chocolate brown
67
In a shunt-wound DC generator, with what generator component are the shunt field windings connected in parallel with?
the armature circuit
68
In D.C. motor construction, where are the commutating windings wound?
interpoles
69
What is the function of the interpoles installed in DC motors?
To provide sparkless commutation without having to shift the brushes.
70
By what means is a synchronous motor started and brought nearly to synchronous speed?
By the use of a squirrel-cage induction winding, also called an amortisseur winding.
71
What causes the rotor of a synchronous motor to operate in synchronism with the rotating field?
the rotor is magnetically locked into step with the rotating magnetic field by the excitation current
72
What would be the effect of carrying field excitation excessively high on a synchronous motor?
a tendency for the motor to overheat
73
In a shunt-wound DC generator, with what generator component are the shunt field windings connected in parallel with?
the armature circuit
74
The electrical diagram shown in figure B of the illustration represents what type of DC motor? Illustration EL-0054
compound-wound DC motor
75
A shaded-pole motor is a specific type of motor included in what class of motor?
single-phase induction motor
76
Which of the terms listed best describes a compound-wound DC generator having a higher voltage at no load than at full load?
Under compounded
77
What function does an equalizing connection between two compound-wound DC generators operating in parallel serve?
parallel the series fields of the generators
78
In a short-shunt cumulatively compound-wound DC motor, how is the shunt field connected?
in parallel with the armature
79
The electrical diagram shown in figure B of the illustration represents what type of DC motor? Illustration EL-0054
compound-wound DC motor
80
When securing an AC generator, what should be your FIRST action in accomplishing the procedural steps?
reduce the load on the unit
81
The counter EMF of a DC motor is maximum when the __________.
motor is at rated speed
82
From the instant of start-up, through the acceleration period, and until the motor reaches rated speed, when is the counter EMF produced in the windings of a DC motor 'zero'?
armature is not yet turning
83
A DC generator which is used to supply direct current in order to provide magnetizing current to an AC generator field is commonly known as what?
exciter
84
Brushes in a DC generator must be positioned in the neutral plane to avoid excessive sparking associated with the brushes. What device is used to prevent the shifting of the neutral plane due to armature reaction for varying generator loads.
commutating pole windings
85
What may cause brush sparking in a DC generator during commutation?
misalignment of the brush rigging
86
What is the item referred to as a pigtail on a DC motor brush rigging?
uninsulated wire
87
How many cells are within in a 24 volt lead-acid battery?
twelve cells
88
Which of the following materials is a good electrical insulator?
wood
89
Which of the listed pairs of materials make the best insulators?
paper and mica
90
In figure of "A" of the illustrated circuit, what is the voltage measured across R1 if the battery voltage is 24 volts, the resistance of R1 is 34 ohms, and the resistance of R2 is 126 ohms when the switch is closed? Illustration EL-0020
150 millivolts
91
The multiplier prefix 'giga' (G) such as used in "gigabytes" represents what multiplication factor?
billion (10 to the 9th power)
92
As shown in figures "B" and "C" of the illustration, what should be the switch position and which test lead terminal jacks should be used if your intent is to measure DC currents anticipated as high as 200 milliamps? Illustration EL-0047
switch position "6" and terminal jacks "1 and 4"
93
Compared to conventional alternators, brushless alternators are designed to operate without the use of what?
slip rings and commutators
94
As shown in the two-speed single winding three phase motor connection diagrams illustrated in figure "B", what is the connection scheme associated with low speed operation? Illustration EL-0118
series delta
95
In the diagram of the switchboard shown in the illustration, if one of the turbines should fail due to a throttle trip, what will happen? EL-0003
device labeled 'BKR' for that alternator should automatically open because of the reverse power relay
96
Assuming the alternator shown in figure "A" of the illustration is equipped with a diode plate as configured in figure "D", what is the purpose of the diode plate? Illustration EL-0037
It rectifies exciter armature AC to DC for rotating main field excitation and eliminates the need for brushes.
97
If the cooling water system is isolated for repairs, but it is still desirable to run the alternator pictured in figure "A" of the illustration, what must be done? Illustration EL-0037
The emergency air inlet panel and air outlet doors must be opened and only then can the alternator be run, but at reduced load.
98
What application would the switchboard instrumentation panel shown in the illustration best be suited for? EL-0040
main AC generator
99
In a three-phase, squirrel-cage type, and induction motor, how is the primary rotating magnetic field established?
application of a three-phase voltage supply to the stator windings
100
How is the difference between the synchronous speed of a three phase induction motor and its operating speed correctly expressed?
slip
101
As shown in the two-speed single winding three phase motor connection diagrams illustrated in figure "B", what is the connection scheme associated with low speed operation? Illustration EL-0118
series delta
102
If a three-phase induction motor is operated under a light load and it develops an open in one of its supply lines, what will be the result?
the motor continue to run, but will vibrate and have reduced torque
103
In testing a three-phase delta-connected winding for an open circuit using a ohmmeter, what must be done?
if possible, open the delta-connections to avoid shunting the phase being tested
104
Which of the following statements is true concerning the operating characteristics of a basic squirrel-cage induction motor?
Rotor slip is dependent upon the motor load.
105
What type of rotor is used in the split-phase family of single-phase motors?
Squirrel-cage
106
What is the function of the squirrel cage windings installed on a synchronous motor rotor?
provide starting torque
107
What is the purpose of the squirrel-cage windings included as part of a synchronous motor?
provide a means for starting
108
What type of motor is illustrated by the schematic of figure "B" of the illustration and what type of starting relay is used? EL-0209
capacitor start, induction run motor using a potential starting relay
109
What is the name of the DC motor speed control method utilized as shown in figure "B" of the illustration? Illustration EL-0101
Ward-Leonard
110
In referring to the illustration of the Ward-Leonard drive system, what type of DC generator is used? (EL-0153)
Separately excited generator.
111
For what reason should engine room watch standers keep a constant check on the loads carried by electric motors?
exceeding nameplate currents shortens useful life
112
In order to properly set up programmable motor protection, it is necessary to know the locked rotor current of a motor. Given the chart of code letters for locked-rotor kVA/HP and the necessary instructions shown in the illustration, calculate the estimated locked rotor current for the motor represented by the illustrated motor nameplate using a mid-range value for the code letter, assuming the motor is to run at 440 VAC. EL-0175
43.7 amps
113
As shown in figure A" of the illustrated motor nameplate, how much current could the motor safely draw on a continuous basis at sea level without overheating? EL-0171
187 amps
114
As shown in the illustration, using the instructions provided and Chart "A" and Table "24", what size overload relay heater would be the proper selection for the motor associated with the motor nameplate data shown assuming the motor operates at sea level and that the motor and its starter share the same ambient temperature? EL-0171
G30T20
115
For the purposes of safety and determining the shock hazard, nominal voltage is defined as the normal electrical system design voltage. This can be determined from what
is displayed on nameplates, data plates, schematics, or single-line diagrams. What does the nominal voltage represent?
average of phase to phase and phase to hull ground voltages
116
Which of the illustrated motors has an open, drip-proof (ODP) motor enclosure? EL- 0001
C
117
Which of the illustrated motors has a totally enclosed, fan-cooled (TEFC) motor enclosure? Illustration EL-0001
A
118
With respect to electrical enclosure types, how may an electric motor be designed and constructed?
explosion proof
119
Why should a breakable, mercury-filled thermometer NOT be used in a lead-acid battery to measure electrolyte temperature?
accidental breakage can cause severe sparking and explosions
120
What device is used so that the kilowatt load sharing can be adjusted on paralleled generators?
governor control
121
Referring to the impressed current cathodic hull protection system shown in the illustration, if required to control the impressed current to the anodes manually by using the hand adjustment potentiometer, what parameter should be maintained at a constant value? (EL-0090)
Reference control voltage
122
Referring to the impressed current cathodic protection system shown in the illustration, if required to control the current to the anodes manually by using the hand adjustment potentiometer, what statement best represents the changes that should prompt one to recheck the reference electrode voltage (hull potential)? (EL-0090)
Changes in vessel speed, sea water temperature, and sea water salinity should all prompt rechecking.
123
Electrical wire in general, when used aboard vessels must meet minimum requirements. Which of the following statements is/are correct?
Wire must be of the stranded copper type.
124
According to 46 CFR, Subchapter J (Electrical Engineering), when considering replacement, instrument and control wiring in a switchboard is to be of what minimum size?
14 AWG
125
As shown in the illustrated devices and symbols, which of the devices represents an open general purpose relay? Illustration EL-0005
A
126
As shown in the illustrated devices and symbols, which of the symbols shown in the illustration represents a standard normally closed relay contact? EL-0005
F
127
What will be the resulting current when a voltage of 110 VDC is applied to a resistance of 32 ohms in figure "A" of the illustrated circuit when the switch is closed? Illustration EL-0018
3.44 amps
128
What will be the resulting current when a voltage of 442.7 VDC is applied to a resistance of 1.25 ohms in figure "A" of the illustrated circuit when the switch is closed? Illustration EL-0018
354.16 amps
129
What will be the resulting current when a voltage of 12 VDC is applied to a capacitance of 470 microfarads in figure "C" of the illustrated circuit after the capacitor has had ample time to fully charge? EL-0018
0.0 amps
130
How is the speed of a squirrel-cage induction motor determined?
number of stator poles
131
Which of the following statements is true concerning the motor controller circuit shown in the illustration? Illustration EL-0004
The controller is configured for use with a three phase non-reversible squirrel-cage induction
motor.
132
Concerning the illustrated motor controller circuit, where is the location of the motor "run" indicator light? EL-0004
At the remote control station.
133
Which of the following statements is true concerning the motor controller circuit shown
in the illustration? EL-0004
The controller is configured for across-the-line (direct-on-line) starting.
134
When a motor is started by the controller shown in figure "C" of the illustration, what circuit components are in the holding current flow path through the control circuit while the motor is in operation? Illustration EL-0010
the stop button contacts, the "B1" contacts, the "M" contacts, the "M" coil and the "OL"
contacts
135
What does the symbol labeled "OL" represent as shown in the power circuit on lines T1 and T3 to the motor as shown in figure "A" of the illustration? Illustration EL-0011
overload relay thermal heater
136
If a three-phase motor controlled by the control circuit illustrated in figure "B" of the illustration, is running in the forward direction, which of the following sequences must occur before the motor will reverse rotation? EL-0011
First, the motor must be stopped via the stop button, then normally closed 'F' contacts must re-close, and finally the reverse start button must be depressed.
137
Referring to figure "B" of the illustrated control circuit schematic diagram, which of the
following statements is true when the motor is running in the forward direction? EL-0011
The normally open (NO) "F" contacts are closed.
138
In the lighting distribution circuit shown in the illustrated lighting panel L110 of the illustration, if all circuit breakers are closed and due to a problem with the relevant feeder circuit breaker, there is a loss of power on the incoming phase A, which of the following statements is true? Illustration EL-0013
Half of the accommodation lighting circuits on the 01 deck, port side would lose power.
139
Referring to the containership one-line distribution diagram shown in the illustration, what statement is true concerning the battery charger? (EL-0014)
The battery charger gets its AC power from the 120 VAC section of the
emergency switchboard and is capable of providing DC charging current to only one battery bank at a given time.
140
As shown in the illustration, assuming power is available at the control circuit, which listed action will occur FIRST when the "off-run" switch is placed in the "run" position? Illustration EL-0017
The contactor coil "M" energizes.
141
Which of the following illustrated manual motor starters represents the wiring diagram illustrated in figure "A"? EL-0023
1
142
In the circuit 'B' of the illustration, what would be the result of the upper heating element being burned out and open circuited? Illustration EL-0041
low heat (series) position would result in no heat at allmedium heat (single) position would result in no heat at allhigh heat (parallel) position would result in medium heat
143
Refer to figure "A" representing an electric oven as shown in the illustration. With the oven turned on, the power available indicator light is off, the oven on indicator light is off, and only elements "6" and "7" appear to be producing heat. Which fuse is blown? (EL-0041)
L1 10A line fuse is blown
144
In the illustration shown, what type of protection is provided the potable pump drive motor? Illustration EL-0043
thermal overload protection and low voltage release
145
As shown in figure "A" and "B" of the illustration, the potable water pump is short cycling by the action of the pressure switch as a result of an unusually high level in the potable water hydro pneumatic header tank. What is most likely the cause? Illustration EL-0043
The potable water hydro-pneumatic header tank is in need of recharging with compressed air
due to absorption of air into the water over time.
146
With what device is the RPM of an AC generator indirectly measured on a switchboard when operating singly (no other generator connected to the bus)?
synchroscope
147
Which of the diagrams shown in the illustration depicts the proper method of aligning brushes on a commutator for a DC machine? Illustration EL-0057
C
148
Which of the pictured motors within the split phase family of single phase induction motors represents a capacitor start, induction run motor? Illustration EL-0146
A
149
Which of the pictured motors within the split phase family of single phase induction motors represents a split phase, resistive start, induction run motor? EL-0146
C
150
Which of the following motors has a frame configuration for solid base mounting only? EL-0184
A
151
If a digital multimeter is set up as shown in figure "A" of the illustration, what would be displayed on the screen if the fuse being tested is not blown and has proper continuity? Illustration EL-0210
0.001 ohms
152
If a digital multimeter is set up as shown in figure "A" of the illustration, what would
be displayed on the screen if the fuse being tested is blown? EL-0210
OL ohms
153
As shown in all four diagrams included in the illustration, what type of logic circuit is represented? (EL-0231)
XOR gate
154
As shown in all four diagrams included in the illustration, what type of logic circuit is represented? (EL-0233)
NAND gate
155
As shown in all four diagrams included in the illustration, what type of logic circuit is represented? (EL-0227)
OR gate
156
As shown in all four diagrams included in the illustration, what type of logic circuit is represented? (EL-0226)
AND gate
157
As shown in all four diagrams included in the illustration, what type of logic circuit is represented? (EL-0231)
XOR gate
158
Referring to figure "1" of the illustration, what type of logic gate is symbolized? (EL- 0035)
OR gate
159
Referring to figure "2" of the illustration, what type of logic gate is symbolized? (EL- 0035)
NOR gate
160
Referring to figure "3" of the illustration, what type of logic gate is symbolized? (EL- 0035)
AND gate
161
Referring to figure "4" of the illustration, what type of logic gate is symbolized? (EL- 0035)
NAND gate
162
Referring to figure "5" of the illustration, what type of logic gate is symbolized? (EL- 0035)
XOR gate
163
For what reason should engine room watch standers keep a constant check on the loads carried by electric motors?
exceeding nameplate currents shortens useful life
164
As shown in figure A" of the illustrated motor nameplate, how much current could the motor safely draw on a continuous basis at sea level without overheating? EL-0171
187 amps
165
How is the power factor of an AC generator operating singularly determined?
the connected load
166
Which of the following is a disadvantage of electric drive propulsion systems?
Propulsion motors are required along with electrical power generation machinery.
167
What type of motor is generally used in DC propulsion drive systems?
shunt wound
168
What statement is TRUE concerning the Azipod propulsion system?
It is an electric drive system where the propulsion motor is installed in a submerged housing capable of swiveling.
169
What does the component labeled "B" shown in the illustration represent? Illustration EL-0093
hand-cranked generator
170
As shown in the illustration, which of the following statements is correct concerning the circuits in a sound powered telephone system? Illustration EL-0093
The talking circuit is a common circuit and the ringing circuit is a selective circuit. .
171
In the system shown in the illustration, the engine room station is unable to signal any other station, nor is any other station able to signal the engine room station. The engine room station can, however, ring itself by proper positioning of its selector switch. What is the most probable cause of this problem? Illustration EL-0093
There is an open between terminal "C" of the problem station and the common wire of the
multi-conductor cable to the other stations.
172
What type of equipment does the wiring diagram shown in the illustration represent? EL-0093
sound powered telephone system
173
Where is the power necessary to energize the howler "relay" coil at the engine room station as shown in the illustration? Illustration EL-0093
comes from each station's hand cranked generator
174
What is the name of the mechanism used to transmit rudder angle information from the steering gear itself to the wheelhouse in the illustrated rudder angle indicator system? EL-0092
synchronous transmission
175
In actual applications, electrical connections associated with 'R1, R2 and R3' of the transmitter to 'R1, R2, and R3' of the indicators shown in figure "C" of the illustration are made by what means? EL-0092
slip rings and brushes
176
Which of the illustrated resistors represents the schematic symbol shown in figure "C"? Illustration EL-0021
figure "6"
177
Which of the pictured solid-state semiconductor devices in the illustration is a rectifier bridge? Illustration EL-0068
3
178
What is the name of the device shown in figure "2" of the illustration? Illustration EL-0068
power rectifier diode
179
Which of the pictured solid state semiconductor devices is a light-emitting diode? EL- 0068
7
180
Concerning the illustrated motor controller circuit, where is the location of the motor "run" indicator light? EL-0004
At the remote control station.
181
Which of the following statements is true concerning the motor controller circuit shown in the illustration? EL-0004
The controller is configured for across-the-line (direct-on-line) starting.
