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1
62. What is used in most for starting three-phase induction motors of five (5) horsepower or less ?
across-the-line starters
2
63. Periodic testing of circuit breakers is necessary to assure that a correct rated and properly installed unit
will continue to provide the original degree of protection
3
64. You are testing the insulation in an AC generator with with a megohmeter. the resistance value of a dry, clean winding will_
continue to rise as the test potential is maintained, becoming fairly steady as the leakage current stabilizes
4
65. Which of the following data is required to draw the circle diagram for an induction motor?
Bolck rotor test, no load test and stator resistance test
5
66. The removal of paint from electrical equipment such as generators, should be cautiously undertaken because
the paint dust is composed of abrasive and semi-conducting materials which impair insulation
6
67. A reversible electric motor with worm gear that is connected to the flywheel to position engine parts is the
turning gear
7
68. If a small electric motor is immersed in salt water it should be I. washed in fresh water II. dried in an oven III. blow air until it dries
I only.
8
69. To carry out an insulation resistance test, one terminal of the megohmmeter should be connected to the winding, with the other terminal being connected to the
frame of the machine
9
70. Before working on an electric motor starter panel located on the main deck, what should you do FIRST?
Open the circuit breaker and tag out
10
71. A fuse the blows often should be replaced only with a fuse of __.
the recommended current and voltage rating
11
72. Electrical Insulating rubber gloves should be dielectrically tested every how many months?
6 months
12
73. It is a type of temperature sensor that has the characteristic of being very accurate, linear and has a good long term stability.
RTD'S
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74. A self-excited DC generator fails to come up to its normal 440 volts. What could be the probable cause?
low armature speed
14
75. A common type of protective covering used on electrical conductors is,
Fibrous braid
15
76. The air gap provided in induction motors should be checked periodically with a feeler gage to detect an unequal air gap and
Mechanical damage to rotor
16
77. A temperature instrumentation system for an accomodation reefer room consists of a resistance temperature detector (RTD), a measuring bridge circuit and a meter or alarm circuit. Which of the following is true concering the measuring bridge circuit ?
The ressistance bridge is said to be balanced when its output voltage is zero
17
78. Electrically operated safety devices on auxiliary diesel engines functions to stop the engine by
shutting off fuel supply
18
79. A molded-case circuit breaker provides protection against short circuits by using alan ?
electromagnet
19
80. The proper way to apply plastic electrical tape to an electric cable splice is to
wind the tape so that each turn overlaps the turn before it
20
81. The division of kilowatt load between two paralleled alternators is determined by the ?.
load-speed characteristics of the governors
21
82. What is the result if the solenoid coil burns on a cargo winch with an electrical brake?
The brake will be set by spring force.
22
83. The air gap provided an induction motor should be checked periodically with a feeler gage to detect
any increase in rotor bearing wear
23
84. Encrusted dirt accumulated inside a motor should be removed with a
Fiber scraper
24
85. A temperature instrumentation system to an engine room console consists of a resistance temperature detector (RTD), a measuring bridge circuit , and a meter (or alarm circuit). Which of the following statements is true concerning the measuring bridge circuit?
The resistance bridge is said to be balanced when its output voltage is zero
25
86. When a replacing a fuse with one of a higher rating than the original, which of the following is true?
It endangers the apparatus it is supposed to protect
26
87. The purpose of a motor under voltage protection device is to
prevent high armature current when power is restored
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88. The power scale of circle diagram of an induction motor can be found from
short-circuit test only.
28
89. What electrical apparatus can test insulating efficiency in an electric installation?
Megger tester
29
90. When reading electrical motor controller diagrams, it helps to know that
current paths in the power circuit are drawn as heavy lines and in control circuit as lighter lines
30
91. What devices is fitted to prevent the generator windings from absorbing moisture while at standstill?
Space heater
31
92. Any electric motor can be constructed to be?
explosion proof
32
93. A common type of protective covering used on electrical conductors is
rubber or plastic
33
94. Which of the following statements concerning the maintenance of solid-silver Contacts in relay and auxiliary control circuits is correct?
They should be filed with a fine-cut file when projections extend beyond the contact surface
34
95. What can you do if the generator is exposed to rain or any water?
Make a megger test
35
96. What is the cause when an alternator failed to produce line voltage?
exciter generator failure
36
97. Moisture as a result of condensation occurring inside of the cargo winch master switches, can be reduced by?
using strip heaters inside the switch box
37
98. Regulations require each motor controller to have a wiring diagram located
on the inside of the controller door
38
99. A device which can be used to check the calibration of a circuit breaker is a
portable low voltage high current testing unit
39
100. Which of the following statements concerning analog and digital devices are correct?
The variables in digital systems are fixed quantities and the variables in analog systems are continuous quantities.
40
101. When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter's pointer ?
kicking slightly down scale as voltage is applied
41
102. In using the Rheostat, what do you call the circuit of the motor to adjust the speed?
Induction motor with wound-rotor
42
103. How can you restore the charge of a lead-acid battery?
passing a direct electric current through the cell
43
104. In an impressed current cathodic protection system, what is anode
insulated from the hull and does not waste away,
44
105. Complete maintenance of electrical motors should include periodic checks for machine
vibration
45
106. The automatic voltage regulators provide on switch boards has function to
vary the field excitation to the generators
46
107. If a delicate component must be soldered into a circuit the component may be protected from the heat of the soldering process by.
Using a thermal shunt
47
108. What maximum voltage can Class 00 electrical insulating rubber gloves can be used?
500 volts
48
109. Which of the following statements represents the FIRST step in seating new brushes on slip rings?
Lay sandpaper between the brush and the slip ring and slide the sandpaper back and forth under the brush.
49
110. Which of the following statements is true concerning the cleaning of electrical contacts?
Delicate parts should be cleaned with a brush and an approved safety solvent.
50
111. What indicates the third color band on a resistor?
number of zeros following the first two significant figures in the resistance value
51
112. What would indicate ground in a particular phase 3 - phase low voltage distribution system?
dark or dim switchboard ground detecting light
52
113. While trouble shooting a circuit in an engine room central control console, a resistor is suspected of being faulty. Which of the following precautions must be observed if an ohm meter is to be use to check its value?
Resistor circuit must be de-energized and at least one end of the component isolated
53
114. Which of the following statements best describes the material known as varnished cambric?
Cotton cloth coated with insulating varnish.
54
115. What is the first step to properly use a hook-on-type voltammeter in checking current flow?
hook the jaws of the instrument around the insulated conductor
55
116. Upon failure of the normal power supply, the emergency generator is placed on the line by the
automatic bus transfer devise
56
117. Where a thermal-acting breaker is required to be used in an area of unusually high, low, or constantly fluctuating temperatures, an ambient compensating element must be used. What does this element consist of?
second bimetal element
57
118. Which of the listed precautions should be observed before spraying liquid solvent on the insulation of an electric motor?
Disconnect the motor from the power source.
58
119. The electrolyte in a lead-acid storage battery consists of distilled water and ?
sulfuric acid
59
120. The insulation resistance of electric equipment and machinery should be tested for lowest normal insulation valves
immediately after shutting down of the machine
60
121. How much is the typical resistance of the body from hand to foot when dry?
500 ohms
61
122. How will you remove a tubular fuse from a fuse panel with ?.
fuse pullers
62
123. Which device that commonly utilizes the principle of electromagnetic induction?
transformer
63
124. When a lead-acid battery begins gassing freely while receiving a normal charge, what should you do when charging?
be decreased
64
125. In the circle diagram for induction motor, the diameter of the circle represents
rotor current
65
126. What is a three-layer bidirectional device used primarily as a trggering device with junctions heavily and equally doped?
Diac
66
127. Two contributors of electronic console failures are heat and vibration. To combine some of their effect, preventive maintenance procedures should include
periodic changing or cleaning of console ventilation and control room air conditioning filters