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Transcript
F2 (OIC) 1. AC and DC generators are similar in the sense that they are ______. a. Both producing alternating voltages b. Both control the delivery of voltages c. Both supply 3 – phase power d. Constructed at the same size for the same KW rating Ans. A 2. A DC shunt generator has its field windings connected in ______. a. Series with series windings b. Parallel with the rheostat c. Series with armature windings d. Parallel with the armature windings Ans. D 3. What will the phase relationship of a six – pole, three – phase, rotating field generator? a. 60 degrees b. 120 degrees c. 180 degrees d. 360 degrees Ans. B 1 4. In an AC generator, direct current from a separate source is passed through the windings of the rotor ____________. a. By means of slip rings and brushes b. By means of commutator c. By means of rotating bar magnet d. By means of rotating coil Ans. A 5. The main purpose of an electric space heater fitted on large AC generators is to ______________. a. Keep the unit warm for immediate starting b. Prevent moisture from accumulating in the windings during shutdown c. Prevent windings from getting brittle d. Prevent dirt from entering the windings Ans. B 6. One factor that determines the frequency of an alternator is the _____________. a. Armature coil of windings b. Number of magnetic poles c. Strength of the material used d. Output current Ans. B 2 7. The frequency output of an operating alternator is controlled by the ____________. a. Speed of the motor poles b. Armature coil windings c. Strength of the materials used d. Output voltage Ans. A 8. The cycle per second developed by the alternator aboard ship depends on _____________. a. Speed of engine driving the alternator b. Resistance applied to the transformer c. Speed of the induction motor d. Voltage regulator output Ans. A 9. To raise the frequency of an AC generator in service, the operator should ____________. a. Increase the feed to the transformer b. Increase the speed of the diesel engine driving the AC generator c. Reduce the load in the system d. Increase the number of magnetic poles Ans. B 3 10. The frequency of an AC generator is adjusted by means of the ______________. a. Governor control of the diesel engine driving the AC generator b. Transformer adjustment c. Raise or lower load in the system d. Raise field excitation Ans. A 11. What will happen to the prime mover of AC generator if the load is removed? a. Speed of the engine will increase slightly then return to original speed b. Speed of the engine will decrease slightly then return to original speed c. Speed will remain the same d. Engine will shut down Ans. A 12. As load is added to an AC generator, the prime mover speeds will ______________. a. Increase b. Decrease c. Remain the same d. None of these choices Ans. B 4 13. The slowing down of AC generator prime mover speed every time a load is added will be raised to original speed by the _______________. a. Governor b. Nozzle valve c. Stop engine d. Field rheostat Ans. A 14. When securing an AC generator, you are obliged to ______________. a. Reduce the load on the circuit b. Trip the generator circuit breaker c. Stop the engine d. Switch the voltage regulator to “manual” Ans. A 15. A change in field excitation of an alternator operating in parallel will bring change to its ___________. a. Frequency b. Current output c. Voltage output d. Kilowatt load Ans. C 5 16. A vessel is equipped with two ship’s service generators. Generator #1 is rated at 900 KW and the generator #2 is rated at 600 KW. During parallel operation and a total ship power load of 1,000 KW, the KW load on generator #2 will be __________________. a. 100 KW b. 200 KW c. 400 KW d. 600 KW Ans. C Given: DG1 = 900 kw DG1 = 900 X 100% = 60% DG2 = 600 kw 1,500 Bus load = 1,000 kw DG2 = 600 Find: DG2 kw load? 1,500 X 100% = 40% Solution: Total Load CAP = DG1 + DG2 DG2 Load Shared at 40% of = 900 kw + 600 kw 1,000 kw bus load = 1,500 kw = 1,000 kw x 0.40 Load Sharing % (characteristic) = 400 kw 17. How is the DC output obtained from a brushless exciter? a. Directly from the commutator by induction b. By the use of ship rings mounted on the armature c. By the use of semiconductor rectifier mounted on the exciter armature d. By the use of semiconductor rectifier mounted on the stator Ans. C 18. Chattering of the slip ring brushes on a generator maybe remedied by ____________. a. Brush holders lubrication b. Re-insulating the brushes c. Increasing the length of pigtail d. Cleaning the slip rings Ans. D 6 19. If an AC generator experience voltage failure, the cause may be ______________. a. An open in the field circuit b. Brushes shifting out of place c. Rotating slip ring out of contact d. Excessive locked-rotor current Ans. A 20. Voltage failure of an AC generator may be caused by ___________. a. Failure of the exciter generator b. A tripped bus circuit breaker c. High mica segments on the stator bus bar d. Excessive prime mover speed Ans. A 21. An alternator will fail to produce line voltage as result of ____________. a. Open circuit breaker b. Exciter generator failure c. Wrong position of the brushes d. Worn out slip rings Ans. B 7 22. Two AC generators of the same capacity are operating in parallel. One with zero speed droop setting and the other with 5% speed droop. If its capacity is not exceeded, the unit that has zero setting will ____________. a. Take smaller share of load b. Have poor power output c. Have poor power characteristics d. Maintain the frequency of the system Ans. D 23. When paralleling two AC generators, the frequency of the incoming generator prior to closing its breaker should be___________. a. Higher than bus frequency b. Lower than bus frequency c. Same as bus voltage d. Slightly higher than bus frequency Ans. D 24. You are attempting to parallel two AC generators, and the synchroscope pointer is revolving fast in the clockwise direction. It means that the incoming AC generator frequency is _______________. a. Higher than the bus frequency b. Lower than the bus frequency c. Same as bus frequency d. Much higher than the bus frequency Ans. D 8 25. The load sharing characteristics of two diesel generator engines operating in parallel are mostly dependent on their governor ____________. a. Speed droop setting b. Load limit setting c. Speed limit setting d. Idle speed setting Ans. A 26. The diversion of load between two parallel running generators is determined by the ____________. a. Characteristics of governors b. Field excitation of the engines c. Number of poles in the alternator d. All of the choices Ans. A 27. The kilowatt load is evenly distributed between two alternators just placed in parallel by adjusting its ______________. a. Balance flywheel b. Governor settings c. Transformer output d. Field excitation Ans. B 9 28. Equal load factors on paralleled AC generators are maintained by an automatic _____________. a. Voltage regulator b. Power relay c. Governor switch d. Reverse current relay Ans. A 29. Why is it desirable to operate paralleled AC generators at the same power factor? a. Circulating currents are kept to a minimum b. Field excitation losses are kept to a minimum c. Generator governors are less likely to hunt d. All of these choices Ans. A 30. Attempting to parallel an AC generator that is out of phase with the bus will result in ___________. a. A breaker trip b. KW increase c. Synchronization lamp damage d. Non – working power factor Ans. A 10 31. After closing the circuit breaker to place the two similar alternators in parallel, the next step is to balance the _______________. a. Power factor b. Voltage load c. Current load d. Kilowatt load Ans. D 32. Two parallel alternators are operating near rated load. If one trips out mechanically, the operator should immediately _____________. a. Restart the tripped machine b. Switch off all non – essential loads in the circuit c. Start the generator d. All of these choices Ans. B 33. You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the counterclockwise direction. This indicates that the incoming generator frequency is __________. a. Higher than bus b. Lower than bus c. Same as bus d. Out of order Ans. B 11 34. Which of the following problem will occur if the circuit breaker of the incoming alternator is closed and it is 180 degrees out of phase with the loaded alternator? a. The rotor of the incoming alternator will hunt b. The rotor of the incoming alternator will stop c. It could damage the incoming alternator due to severe cross current d. Both alternators will be out of phase by 180º Ans. C 35. When paralleling two alternators, the synchroscope pointer approaches 0 degree position. This indicates that the alternator frequencies are ______________. a. 180º out of phase b. Incoming alternator is in phase with the bus c. Synchroscope lamps are broken or damaged d. Incoming alternator is running too fast Ans. B 36. When paralleling two alternators, the synchronizing lamp grows dim. This indicates that the incoming alternator is _______________. a. Ready for closing the circuit breaker b. Voltage is 180º out of phase c. Synchronization lamp is defective d. Running too slowly Ans. A 12 37. The number of complete cycles of AC or voltage completed each second is called the _____________. a. Frequency b. Period c. Wave length d. Hour Ans. A 38. Which of the following statements does not represent Electromagnetic field intensity factor? a. The number of turns of wire in the coil b. The amount of current flowing in the conductor c. The ratio of the coil length to the coil d. The resistance in series with the load Ans. D 39. When applying the left-hand rule for generators, your thumb will point to the ___________. a. Direction of rotation b. Direction of magnetic flux c. Direction of current flow d. Direction of induced voltage Ans. A 13 40. When applying the left-hand rule for generators, your forefinger will point to the ___________. a. Direction of rotation b. Direction of current flow c. Direction of magnetic flux d. Direction of induced voltage Ans. C 41. When applying the left-hand rule for generators, your middle finger will point to the ___________. a. Direction of rotation b. Direction of current flow c. Direction of magnetic flux d. Direction of induced voltage Ans. B 42. The characteristic of an electrical circuit that opposes the starting, stopping or changing of current flow is called a/an ___________. a. Inductance b. Capacitance c. Electromotive force d. Magnetic field Ans. A 14 43. This is developed whenever there is relative motion or action between a magnetic field and a conductor. It is called __________. a. Electromotive force b. Electromagnetic field c. Current d. Voltage Ans. A 44. Which of the following statements will affect the capacitance value of a capacitor? a. The area of the plates b. The distance between the plates c. The dielectric constant of the material between the plates d. The flow of current in the circuit Ans. D 45. Capacitance __________. is measured a. Farads b. Capacitor c. Henry d. Electrons Ans. A 15 in units called 46. The following is a device that transfers electrical energy from one circuit to another by electromagnetic induction. It is a ___________. a. Transformer b. Battery c. Generator d. Rectifier Ans. A 47. The part of a transformer whose function is to deliver the load received is called the __________. a. Primary winding b. Magnetic flux c. Secondary winding d. Rectifier Ans. C 48. The part of a transformer whose function is to receive power from the electric source is called the _______. a. Primary winding b. Secondary winding c. Core d. Enclosure Ans. A 16 49. The total voltage induce into the secondary windings of a transformer is determined mainly by the ratio of the number of turns in the primary to the number of turns in the secondary and by the_________ a. Amount of voltage applied to the primary windings b. Amount of current applied to the primary windings c. Amount of resistance applied to the primary windings d. Length of wire in the primary winding Ans. A 50. Depending on their atomic structure, different materials have different quantities of free electrons. Therefore, the various conductors used in electrical applications have different values of__________. a. Resistance b. Sizes c. Weight d. Length Ans. A 51. In electrical circuit, the resistance unit of measure is specified in ___________. a. Ohm b. Farad c. Volts d. Watt Ans. A 17 52. The heat dissipating capability of a resistor is measured in ______________. a. Watt b. Ohm c. Ohm d. Ampere Ans. A 53. Which of the following electronic component store electrical energy? a. Capacitor b. Transistor c. Resistor d. Diode Ans. A 54. Assume that a 208 volt is applied to the autotransformer and there is a 10.4 resistive load connected to the secondary winding of the transformer. The output voltage of the secondary winding is 104 volts. The load current should be ____________. a. 10 amperes b. 1.0 amperes c. 2.0 amperes d. 20 amperes Ans. A 18 55. The direction of rotation of an induction motor is___________________. a. Opposites the rotating field direction b. The same as the direction of the rotating field c. Determined by the number of poles d. Determined by the staggering of the brushes Ans. B 56. A switchboard for an AC electrical distribution system will be provided with which of the following components? a. Frequency meter b. Ammeter c. Voltmeter d. All of these choices Ans. D 57. The numbers cells in a 12 – volt lead acid battery is ____________ a. 3 cells b. 4 cells c. 6 cells d. 12 cells Ans. C 19 58. An accidental path of low resistance, allowing a passage of abnormal amount of current is known as ______________. a. Open circuit b. Short circuit c. Polarized ground d. Ground reference point Ans. B 59. Possible phase relationships between voltage and current in an alternating current circuit include which if the following conditions? a. Current and voltage may be in phase b. Current may lead the voltage c. Current may lag the voltage d. All of these choices Ans. D 60. The part of the shipboard electrical system used to control the distribution of power to the branch circuit is the ______________. a. Bridge control panel b. Disconnecting links c. Governor relay box d. Main switchboard Ans. D 20 61. Handled phase sequence indicators are useful when ______________. a. Preparing to parallel alternators b. Connecting lighting branch circuits c. Trouble shooting DC meters d. Connecting power lines to the ship Ans. D 62. The open circuit voltage of a fully charged lead – acid battery cell is _________. a. 1.5 volts b. 1.8 volts c. 2.0 volts d. 2.3 volts Ans. C 63. The purpose of a DC generator brushes is to________________. a. Neutralize armature reaction b. Conduct electric current to an outside circuit c. Convert DC current to AC current d. Provide excitation to a DC generator Ans. B 64. Fuses are rated in ________________. a. Voltage b. Amperage c. capacity d. All of these choices Ans. D 21 65. The simplest methods of controlling the terminal voltage of compound wound DC generators are with a ______________. a. Hand-operated field rheostat connected in series with the shunt field circuit b. Separate exciter in a series with the load c. Carbon pile regulator in series with the load d. Balance coil diverting neutral current through the shunt field Ans. A 66. In a 15 horse power induction type motor with a cage rotor, the current required at stand still to produce starting torque is approximately _________________. a. Half the full load current b. Equal to the full load current c. Five time the full load current d. Ten to twenty times Ans. C 67. Which of the following components are to assemble a fluorescent lighting system? a. Lamp b. Starter c. Ballast d. All of these choices Ans. D 22 68. Motor controllers or starter contacts may become pitted and welded together if the contact is ____________. a. Opened under loaded conditions b. Close slowly with light pressure c. Opened too quickly and arc d. Closed quickly with proportionate pressure Ans. B 69. When placed in a magnetic field, which of the materials listed will maintain the highest permeability? a. Glass b. Bakelite c. Soft iron d. Aluminum Ans. C 70. The governor control switch of an alternator is moved to the raise position. These actions will _________. a. Raise the no-load speed setting of the governor b. Raise the percentage of speed droop c. Lower the no-load speed setting of the governor d. Lower the percentage of speed droop Ans. A 23 71. Which of the following will happen to the alternator frequency if the load is removed from a turbo generator whose governor has 3% speed droop? a. It will remain unchanged b. It will decrease by approximately 3% c. It will become variable d. It will increase Ans. D 72. As a load is added to an Ac generator provided with constant field excitation, the prime mover slows down with the effect of _______________. a. Lowering frequency and lowering generated voltage b. Increasing frequency and increasing generated voltage c. Increasing frequency and lowering generated voltage d. Lowering frequency and increasing generated voltage Ans. A 73. The charge of lead –acid battery is checked with a/an ________________. a. Manometer b. Hydrometer c. Voltmeter d. Ohmmeter Ans. B 24 74. The cycles per second developed by the alternator aboard your vessel is determined by ______. A. Speed of the engine driving the alternator B. Resistance applied to the field rheostat C.Synchronous speed of induction D.Adjustment made to the voltage regulator Ans. A 75. When the operating handle of a molded-case circuit breaker is in the mid-position, it indicated that the circuit breaker is _____________. a. On b. Off c. Reset d. Tripped Ans. D 76. Which of the following listed devices may be installed on a large diesel – electric alternating current propulsion circuit breaker is ____________. a. Temperature detector coils inserted in the stator slots for measuring stator temperature b. A CO2 fire extinguisher system c. Electric space heaters to prevent condensation of moisture d. All of these choices Ans. D 25 77. On AC vessels, which of the following statements represents the most difficult problem involved in obtaining a DC potential suitable for use by computer components? a. Step – down transformer is always required b. Vessel vibration affect the voltage source c. The voltage must be rectified and made ripple free d. Rectifiers cannot operate with voltage regulators Ans. C 78. The power factor of an AC generator operating singularly is determined by the ___________. a. Connected load b. Prime mover speed c. Field Excitation d. Generators rated voltage Ans. A 79. When the voltage remains constant and the resistance is increased in a series circuit, the flow of current _____________. a. Increases by the square of the original value b. Increase c. Remains the same d. Decreases Ans. D 26 80. The voltage output of an Ac generator is accurately controlled by ____________. a. Changing the sensitivity of the prime mover to large changes in voltage b. Varying the reluctance of the air gap c. Varying the DC exciter voltage d. Shorting out part of the armature windings Ans. C 81. Under which of the following conditions will a lead – acid battery be given a test discharge”? a. To determine its capacity b. Whenever a cell cannot be brought within 10 point of full charge specific gravity c. When one or more cell are found to have less normal voltage after an equalizing charge d. All of these choices Ans. C 82. A slow continual loss of electrolyte level from one cell of a storage battery could be due to __________. a. A cracked casing b. Too low charging rate c. The specific gravity being higher than normal d. One filler cap installed too tightly Ans. A 27 83. Nickel cadmium batteries are superior to leadacid batteries at high discharge rates because they __________. a. Deliver a large amount of power and can be recharge in a shorter time b. Need fewer cells in connected series and less mounting space c. Have higher output voltages and require no maintenance d. None of these choices Ans. A 84. When power is restored after a complete power failure a steering gear pump will_____________. a. Have to be restored b. Have to rest c. Restart automatically d. Trips its overload relays Ans. C 85. Basic electric motor action depends on________________. a. A conductor rotated with a magnetic field b. A current carrying conductor placed in a magnetic field c. The relative fore of the commutator and commutating poles d. The relative force of the armature and inter poles Ans. B 28 86. As a load is added to shunt motor, the motor will____________. a. Speed up b. Continue to operate c. Slow down slightly d. stop Ans. C 87. The frequency of an alternator is controlled from the main switchboard by adjusting the _________. a. Frequency b. Voltage regulator c. Governor control d. Synchroscope switch Ans. C 88. In order to take a current reading with a “clampon” ammeter, the instrument jaws______. a. Should remain open b. Cannot touch the adjacent conductor c. Must be fully closed or should remain closed d. Will act a transformer primary Ans. C 29 89. When the ship board electrical distribution circuits are connected in parallel, additional parallel circuits will cause the total circuit resistance to_______________. a. Increase causing a drop in the line current b. Increase causing a decrease in the line voltage c. Decrease causing an increase in the line voltage d. Decrease causing an increase in the line current Ans. D 90. When the voltage and current developed in an Ac circuit reach their peak values at the same time, the power factor is _____________. a. Lagging b. Leading c. Maximum d. Minimum Ans. C 30 91. You are attempting to a parallel two AC generators and the synchroscope pointer stops at a position other than zero. If you close the circuit breaker at this moment______________. a. The incoming machine will accept all the load b. The incoming machine will trip out on low voltage release c. A hazardous condition will be created by the cross current between the machines d. A hazardous condition will be created by the incoming machine being at a higher Ans. C 92. What type of electric motor is commonly used to start small auxiliary diesel engines? a. Synchronous b. Series c. Shunt d. cage Ans. B 93. “Dielectric” is/an _______________. a. Electrical insulator b. Current flow c. Good conductor d. Semiconductor Ans. A 31 94. A galvanometer is an instrument used to measure _________________. a. Thickness of galvanized metal b. Resistance of electrical wiring insulation c. Very small amounts of current or voltage d. Quantity of galvons in an circuit Ans. C 95. Electrostatic forces in the high voltage circuits cause indicating instruments to give _____________. a. Parallax readings b. Highly intuitive readings c. Highly accurate readings d. Inaccurate readings Ans. D 96. In an alternating current electrical system, a low system power factor is a direct sign of __________. a. Waste energy b. Efficient operation c. A short in the exciter field windings d. An excessive number of minor system grounds Ans. A 32 97. The voltage of a battery is equal to the _________________. a. Voltage of single cell times the number of cells in the series b. Amperage of single cell times the number of cells in the series c. Efficiency of the number of cells times the resistance d. Voltage of a single cell times the number of cell in parallel Ans. A 98. How many 1.5 volt batteries are required to supply a load of 12 volts if the batteries are connected in series? a. 8 b. 6 c. 12 d. 10 Solution; 12V = 8 pcs. 1.5V Ans. A 99. How many 1.5volt batteries are required to supply a load 12 volts if the batteries are connected parallel? a. 12 b. 6 c. 3 d. None of these choices Ans. D Note; 1.5v batteries cannot supply a load of 12v if it is connected in parallel, because the 33 output voltage is only 1.5v no matter many 1.5v connected in parallel. 100. Three 12 volt storage batteries connected in parallel will give a total voltage of ________. a. 12 volts b. 24 volts c. 36 volts d. 48 volts Solution; VT = V1 = V2 = V3 12V = 12V = 12V = 12V Note; Voltage in a Parallel Circuit never change Ans. A 101. On DC generator, where is the pigtail located? a. Feather spring b. Conductors c. Brush holder d. Spiral adjusting spring Ans. C 102. If a DC generator was rotated in the wrong direction, it would fail to come up to voltage because the _______________. a. Armature field would oppose the field current b. Generator would burn out c. Brushes would burn out d. Circuit breaker would not energize Ans. A 34 103. A generator operates on the principles that_________________. a. When the field revolves, current is generated b. When an armature revolves, a magnetic field is induced c. Voltage is induced when a conductor cuts a magnetic field d. A small voltage in the primary high voltage because of the large number of coils in the secondary Ans. C 104. Frequency of an operating alternator is controlled by the_______________. a. Relative speed of the rotor poles b. Number of turns of wire in the armature coil c. Strength of the materials d. Output voltage Ans. A 105. The line voltage generated by an alternator is adjusted by varying the___________. a. Prime mover speed b. Equalizer bus c. Excitation voltage d. Residual magnetism of the shield Ans. C 35 106. The voltage of an operated AC turbo generator is raised or lowered by adjusting the __________. a. Generator field exciter b. Phase sequence switch c. Generator governor controls d. Synchronizing switch Ans. A 107. What is overall result of increasing the load on the secondary of a transformer? a. Decrease in the primary current b. Decrease in the primary voltage c. Increase in the primary voltage d. Increase the primary current Ans. D 108. In DC circuits, power is expressed as the product of ________________. a. Volts and amperes b. Ohms and amperes c. Volts and coulombs d. Amperes and coulombs Ans. A 36 109. A horse magnet has ______________. a. 2 poles b. 3 poles c. 4 poles d. 1 pole Ans. A 110. Retentivity is the power a metal has retained_______________. a. The current in a circuit b. Magnetic lines force c. Electron plow within the circuit d. Electricity when moving at high speeds Ans. B 111. How many cells are there in a 12 – volt battery? a. 6 b. 4 c. 2 d. 8 Ans. A 112. If the specific gravity of a 12 – volt battery at 80oF is 1.225, the battery is _________. a. Dead b. Fully charged 37 c. Shorted d. Partially charged Ans. D 113. Counter electromotive force is measured in ______________. a. Volts b. Ohms c. Amperes d. Coulombs Ans. A 114. Which of the following expression correctly states Ohms law? a. Volts equal amperes times resistance b. Amperes equals to volts divided by resistance c. Resistance equals volts divided by amperes d. All of these choices Ans. D 115. In a parallel circuit, which of the following is the same throughout the circuit? a. Impedance b. Current c. Voltage d. Resistance Ans. C 38 116. When using Ohms law, V divided by R would solve for________________. a. Amperage b. Voltage c. Resistance d. Watts Ans. A 117. When using Ohm’s law, V divided by I would solve for___________________. a. Amperage b. Voltage c. Resistance d. Watts Ans. C 118. Volts times amperes equals______________. a. Kilowatts b. Watts c. Ohms d. Watts - hours Ans. B 119. The unit of electrical force is the ________. a. Volt b. Amperes c. Watts 39 d. Ohm Ans. A 120. Electrically operated safety devices on auxiliary diesel engines functions to stop the engine by_____________. a. Shutting off fuel supply b. Shutting off air supply c. Shutting off cooling water supply d. Shutting off lube oil Ans. A 121. Before starting an electric motor after a long stoppage, the operator shall ensure that is ___________. a. Dust – free b. Dry c. Moving freely by hand d. Wet Ans. A 122. The insulation resistance of an electric of an electric motor is measured by___________. a. Voltmeter b. Megger c. Ammeter d. Ampere meter Ans. B 40 123. Your contact resistance – to – ground is substantially reduce when you step on a __________. a. Wet floor b. Humid floor c. Dry floor d. None of these choices Ans. A Note; The bodies resistance is greatly reduced when wet. Insulation resistance decreases when wet or with the presence of moisture. 124. Battery rooms must be adequately ventilated to___________. a. Dissipate explosive gases b. Keep room cool c. Supply fresh air d. Protect equipment Ans. A 125. The electrolyte in a lead - acid storage battery consists of distilled water and _______________. a. Electrochloric acid b. Sulfuric acid c. Hydrochloric acid d. Muriatic acid 41 Ans. B 126. A fuse will blow when the current flow_____________. a. Exceeds the rated value b. Remove from the equipment c. Cause the fuse to overheat d. Increase suddenly Ans. A 127. Etched or burned marks on the brushes contact surfaces could be caused by__________. a. Wrong alignment of brushes b. High rotation of rotor c. High rotation of rotor d. Brushes improperly positioned Ans. D 128. In order to comply with the class regulation, the main switchboard onboard modern ships shall have_______________. a. No sharp objects exposed b. No live parts exposed c. Protection covers d. All of these choices Ans. B 42 129. Most of the switchboards main bare parts are insulated with______________. a. Synthetic resin b. Plastic film c. Rubber paint d. None of the above Ans. A 130. The purpose of a main switchboard reverse power trip is to ___________. a. Prevent main circuit overload b. Prevent circuit breaker coil from being damage c. Prevent alternator motorization d. Prevent blackout Ans. C 131. The purpose of the reverse power relay is to trip the circuit in case of _________-. a. Main circuit overload b. Circuit breaker coil from blowout c. Alternator motorization d. Blackout Ans. C 43 132. A generator is prevented from being motorizes by the use of a/an________________. a. Over speed trip b. Reverse power relay c. Back pressure trip d. Over current trip Ans. B 133. A bus disconnect link is used to isolate________________ a. One bus from another b. The generator circuit from the bus c. Other circuits from main switchboards d. Defective alternator Ans. B 134. A switchboard for an AC electrical system requires the use of which device? a. Frequency meter b. Ohmmeter c. Induction voltage regulator d. Current transformer governor Ans. A 44 135. The grounded neutral conductor of a three – wire feeder, in dual voltage 220/110 volt DC switchboard should be _______________. a. Left unprotected for excess current b. Protect with a 115 amp link fuse c. Protect with a 220 amp link fuse d. None of these choices Ans. A 136. The part of the new electrical system that controls the power distribution to the branch circuit is called________________. a. Bridge control panel b. Main switchboard c. 440/220v feeder panel d. Starter panel Ans. B 137. Equipment with temporarily wiring arrangements in cabins, engine rooms and other locations onboard is called________________. a. Unauthorized electrical equipment b. Personal electrical equipment c. Ship’s property d. None of these choices Ans. A 45 138. All switchboards and distribution system must be examined in accordance with _________. a. Company’s preventive maintenance system b. Maker’s recommendation c. Chief engineer’s order d. All of these choices Ans. D 139. Periodical insulation test shall be carried out within the intervals specified in _______. a. Chief engineer order book b. Manufacturer’s instruction book c. Ship’s record book d. Preventive maintenance system Ans. D 140. When passing through restricted waters, such as Panama Canal, Suez Canal or rivers, or in condition of heavy weather it is prudent to use ____________. a. Two generators in parallel b. Three engine watch keepers c. Slow down the engine d. The pilot services Ans. A 141. To ensure that it is ready in case of emergency and for the efficient operation of the 46 emergency generator the engine shall be started once every ______________. a. Week b. Month c. Semi-annually d. Two weeks Ans. A 142. The on – load of emergency generator / alternator must be carried out must be carried out at least every _________. a. Week b. Month c. Semi-annually d. Two weeks Ans. A Note; Ship above 500 GRT 143. All tests done on shipboard emergency components should be entered into the___. a. Engine log book b. Bell book c. Electrician’s record book d. Chief engineer’s record book Ans. A 144. To ensure that the emergency generator is always ready for immediately use, its associated 47 component below shall be kept fully charge at all times. a. Main starting air bottle b. Emergency starting air bottle c. Emergency hydraulic tank d. Auxiliary starting air bottle Ans. B 145. For maintenance of non-sealed batteries, below statements are TRUE except ____________. a. Only the correct electrolytes are to be used b. Cells are regularly inspected and topped up as necessary c. Use only pure distilled water for topping up d. It should be placed in a tightly closed compartment Ans. D 146. For “maintenance – free” batteries, which one statement below is NOT TRUE? a. Only correct electrolytes are to be used b. Cells are regularly inspected and topped up as necessary c. Use only tap water d. Use only sulfuric acid Ans. C 48 147. To protect the radiators of emergency generator sets located external to the main machinery space from very cold weather it must be filled with__________. a. Alcohol b. Distilled water c. Anti – freeze solution d. Anti – boil solution Ans. C 148. All electrical equipment in potentially hazardous atmosphere must be certified as _________. a. Intrinsically safe equipment b. Fool proof equipment c. Tamper proof equipment d. Long lasting equipment Ans. A 149. Before insulation testing is to be done on equipment in hazardous location, the area concerned must be certified as__________. a. Gas free b. Well - ventilated c. Ready for use d. Ready for entry Ans. A 150. Which of the following is NOT considered part of shipboard safety equipment? a. Emergency alarm system 49 b. Fire detection system c. Gas detection system d. Engineer call system Ans. D 151. The cold storage room for meat shall be maintained at _______________. a. – 18oC or better b. – 12 or better c. – 8oC or better d. – 4oC or better Ans. A 152. The vegetable room temperature shall be maintained as near to as: a. – 2oC b. 0oC c. +2oC d. +5oC Ans. D 153. When using electric arc equipment, whenever it is necessary for additional leads to extend the range of operation only correct grade of cable shall be fitted with approved_________. a. Weather proof connectors b. Fully insulated leads 50 c. Cables wires d. None of these choices Ans. A 154. During welding and similar operation, the welder must wear protective clothing such as, but not limited to ___________. a. Welding apron b. Safety shoes c. Safety helmet d. All of these choices Ans. D 155. Goggles and welding masks are worn to protect the welder from ___________. a. Sun rays b. Sparks c. Heat d. Strong wind Ans. B 156. On Ships designated for UMS operation, the engineer on watch must be satisfied that this/ these equipment is / are in good working order before leaving the engine room. a. Automatic controls b. Alarm system 51 c. Fire detection system d. All of these choices Ans. D 157. The fire detection system covering any space shall be kept activated except _____. a. Authorized hot work is taking place b. Testing the system c. Cooking is going on d. It is necessary to isolate the system Ans. A 158. Before shutting down the fire detection system, who shall give prior approval? a. Officer on watch b. Engineer on watch c. Chief engineer d. Master Ans. D 159. Who is the person responsible for the safe, efficient operation and maintenance of the vessel’s electrical system including but not restricted to ____________. a. Chief engineer b. Designated electrical officer c. Engineer on duty 52 d. Master Ans. D 160. As per USCG 33 CFR 164.35, the vessel is not permitted to be operated in US waters unless it has onboard and in properly operating condition _______________. a. Two radars b. Evaporating plant c. Sewage plant d. Oil bilge separator Ans. A 161. Electric shock is often accompanied by falling, which may cause additional physical injury and required__________. a. Hospitalization b. First aid action c. Emergency treatment d. All of these choices Ans. B 53 162. Which of the following statements is correct when you are in contact with a live wire having a 1 ma current? a. Usually harmless but will produce a slight tingling sensation or involuntary movement b. Result in loss of muscle control. This can result in an ability to let go of the energy source, thus increasing the degree of injury c. Enough to result in death d. Can cause internal organ damage and internal burns. Cardiac arrest and respiratory failure may occur. Ans. A 163. Which of the following statements is correct when you get in contact with a live wire having a 5 – 10 ma current? a. Usually harmless but will produce a slightly tingling sensation or involuntary movement b. Result in loss of muscle control. This can result in an ability to let go of the energy source, thus increasing the degree of injury c. Enough current to result in death d. Can cause internal organ damage and internal burns. Cardiac arrest and respiratory failure may occur. Ans. B 54 164. Which of the following statements is correct when you get in contact with a live wire having a 75 – 300 ma current? a. Usually harmless but will produce a slightly tingling sensation or involuntary movement b. Result in loss of muscle control. This can result in an ability to let go of the energy source, thus increasing the degree of injury c. Enough current to result in death d. Can cause internal organ damage and internal burns. Cardiac arrest and respiratory failure may occur. Ans. C 165. Which of the following statements is correct when you get in contact with a live wire having 2 amp and above current? a. Usually harmless but will produce a slightly tingling sensation or involuntary movement b. Result in loss of muscle control. This can result in an ability to let go of the energy source, thus increasing the degree of injury c. Enough current to result in death d. Can cause internal organ damage and internal burns. Cardiac arrest and respiratory failure may occur. Ans. D 55 166. Which of the following is recommended for the rescue and care of shock victim? a. Remove the victim from contact at once b. De – energize the affected circuit and use only non – conductor object to drag or push the victim to safety c. Touch a shock victim who is still in contact with energized circuit d. All of these choices Ans. B 167. One of the easiest ways to create a static charge is ______________. a. By friction b. By lighting c. By applying heat d. By applying electricity Ans. A 168. If transformer are being worked on or inspected, which of the following rules shall apply? a. Remove the transformer from all power source in the primary and secondary circuit b. Removed all the fuses from the power source c. Trip the circuit breaker and take action to prevent their accidental resetting d. All of these choices Ans. D 56 169. A breakable mercury filled thermometer should not be used in a lead acid battery to measure the electrolyte temperature as an accidental breakup can cause __________. a. Severe sparkling and explosion b. Rapid oxidation of the battery plate c. Violent gassing at the positive plates d. Corrosion in the battery terminals Ans. A 170. Flame scanner as used with boiler combustion control system to monitor flame quality and to: a. Shut off the fuel supply of flame is detected b. Occur fuel service pimp in the event of floor fire c. Serviced the forced draft fan in the event of flame failure d. Regulate the fuel air ration for more efficient combustion Ans. A 171. In addition to monitoring flame quality, flame scanners are used in combustion a. Stop the fuel from entering the burner upon detect of flame failure b. Secure the force draft in case of flame failure c. Automatically stop the fuel service pump d. Adjust fuel / air ratio for non efficient combustion Ans. A 57 172. Which of the following represents a limitation to be aware of when the boiler auto combustion control is operated in “hand mode”? a. Boiler safety interlocks are by-passed b. Burner is not capable of full capacity firing rate c. Flame failure is deactivated d. Solenoid valves remain in auto mode Ans. A 173. An over speed trip serves to ______________. a. Stop the engine by cutting off air supply b. Stop the engine by cutting off fuel supply c. Stop the engine by cutting off cooling water supply d. Slow the engine but not stopping it Ans. B 174. An over speed trip stops the diesel engine when the engine a. Runs out of fuel b. Exceeds the set maximum speed c. Has high cooling temp d. Has high exhaust temperature Ans. B 58 175. The over speeding of the diesel engine diving an electric generated could cause _________. a. Damage to windings b. Reverse poser to trip c. Over current to trip d. Excessive exhaust temperature Ans. A 176. The over speed device installed in some engines is automatically actuated by______. a. Expiry force b. Solenoid c. Hydraulic pressure d. Centrifugal force Ans. D 177. An electric tachometer receives the engine speed signal from a _________. a. Small generator mounted as engine b. Bimetallic sensing device c. Slip ring activated d. Stroboscopic sensing device Ans. A 59 178. Another device that detects engine speed is the ________. a. Speed pick-ups mounted at the engine flywheel b. Grounding system slip rings c. Laser light system mounted on the propeller shaft d. Electric governor Ans. A 179. When a fluorescent lamp has reached the end of its useful life, it should be replaced immediately on the resulting flashing may_________. a. Blow the lamp’s circuit breaker b. Explode, causing glass to fly in all directions c. Short circuit the ballast transformer d. Damage the starter and the ballast Ans. D 180. Alternating current circuits developed resistance, capacitance and voltage; the capacitance of capacitor is expressed in ______. a. Ohm b. Henry c. Mho d. Farad Ans. D 60 181. Current flowing only in one direction is called ___________. a. Alternating current b. Omni directional current c. Direct current d. Sinusoidal current Ans. C 182. Electric motors intended for use outside the engine room and boiler are frequently rated at a designated ambient temp. of 40C. What is the equivalent in Fahrenheit? a. 52oF b. 104oF c. 72oF d. 129.6oF Ans. B 183. The rated temperature rise of electric motors is the __________. a. Average temperature at any given latitude b. Temperature rise above ambient temperature at rated load c. Temperature rise to resistance above 10 overload d. Permissible difference in the ambient temperature of the motor due to existing weather conditions Ans. B 61 184. Capacitance is the property of an electric circuit that resists or opposes amp charge of the _____. a. Current in the circuit b. Voltage in the circuit c. Inductance in the circuit d. Resistance in the circuit Ans. B 185. Ambient temperature is the ______________________. a. Normal operating temperature, less the room temperature b. Temperature of the room where the motor is located c. Amount of temperature rise developed by an operating motor d. Temperature of the outside air Ans. B 186. A circuit which a fuse has blown would be categorized as a / an _____________. a. Short circuit b. Open circuit c. Bonded circuit d. Grounded circuit Ans. B 62 187. A circuit is a considered an open circuit when ____________. a. A fuse blown b. It is not in use c. Te supply is in “off” position d. All of these choices Ans. D 188. Electric circuits are protected against overloads and short circuits by means of a/an _________. a. Circuit breaker b. Amplifier c. Diode d. Capacitor Ans. A 189. Incandescent lamps are classified according to _______________. a. Shape and type of service b. Size and style of base c. Operating voltage d. All of these choices Ans. D 63 190. The cross-sectional area of a shipboard electrical cable as expressed on ________. a. Millimeter b. Number gage c. Centimeter d. Circular mills Ans. D 191. When electrical cables generated watertight bulkheads _________. a. They should be grounded on either side of the bulkheads b. They must be bent to radius of six diameters c. A watertight stuffing tube capable of accepting packing should be employed d. They should be secured by clamp Ans. C 192. All electrical cables passing through watertight bulkheads must be __________. a. Installed with watertight tubes b. Grounded a both sides of the bulkhead c. Welded on both sides of the bulkhead d. Fitted with unions on each side of the bulkhead Ans. A 64 193. Copper is often used as an electrical conductor because of ____. a. Has high resistance at low temperature b. Has a highly polished surface c. Has good conductivity d. Holds insulation together well Ans. C 194. Electric cables are formed of stranded wires to ________. a. Increase the current carrying capacity for a given size wire b. Increase their flexibility c. Decrease the weight of the wire d. Assure good conductivity at bend points Ans. B 195. Which of the following characteristics is most critical in determining the size of the cable to be used in a particular circuit? a. Voltage rating b. Weight per unit length c. Current rating d. Inductance for unit length Ans. C 65 196. The electrical energy necessary to power an emergency sound power telephone small vibrating bell obtained from _________. a. Emergency batteries from the general alarm b. Each station’s hand-cranked generator c. Emergency switchboard d. Normal 115/220V power supply Ans. B 197. The electrical energy necessary to transmit a person’s voice air an emergency sound powered telephone circuit is obtained from: a. Dry cell batteries b. Ship service switchboard c. Emergency switchboard d. Speaker’s voice Ans. D 198. The purpose of an impressed current cathodic system aboard ship is to ____. a. Prevent corrosion of the hull propeller, rudder and line shafting b. Neutralize the vessel’s stray magnetic fields which would interfere with radar c. Protect the engine room and deck machinery from oxidation and salty air d. Maintain cleanliness of superstructure Ans. A 66 199. For more complete vessel protection when using an impressed current cathodic system ________. a. All ship’s alternators have temperature sensing device installed b. Straps connected at the propeller shaft and grounded through a ship ring/brush arrangements c. Hull’s magnetic field is aligned with true north d. Machinery on deck and engine room is coated with zinc chromate Ans. B 200. In an impressed current cathodic protection system the anode is _________. a. Connected to the hull and deteriorates with tie b. Insulated from the hull and does not waste away c. Connected to the hull last does not waste away d. Insulated from the hull but deteriorates with time Ans. B 67 201. Impressed current cathodic protection is used on vessels instead of ________. a. Fire alarm system b. Repeated painting c. Sacrificial zincs d. Vacuum tube degaussing system Ans. C 202. Automatic voltage regulators provided a switch board functions to ___________. a. Regulate to AC load on the generator b. Protect the switchboard from high voltage c. Govern prime mover speed to control voltage d. Vary the field excitation to the generators Ans. D 203. In cold weather, the specific gravity of a battery __________. a. Rises b. Lowers c. Remains the same d. None of these choices Ans. A 68 204. If the emergency switchboard pilot light is “ON” it means __________. a. The generator is on line b. The power is available from the generator c. The generator is in parallel with the bus generator d. Pilot exciter is malfunctioning Ans. B 205. Under voltage trips are frequently on switchboard circuits breakers to trip _______. a. Out the generator in the event of severe arching or sparkling b. Out the generator when there is a reversal of power c. Out the generator when there is a low voltage in the main circuit d. The breaker of the generator over speed by 5% Ans. C 69 206. The most common type of AC service generator found aboard ship is the stationary __________. a. Electromagnetic field, revolving armature type b. Electromagnetic field, oscillator armature type c. Armature, oscillatory electromagnetic field type d. Armature, rotating electromagnetic field type Ans. D 207. Brushless AC generators are designed to operate without the use of _________. a. Brushes b. Slip rings c. Commutators d. All of these choices Ans. D 208. Voltage generated by most AC generators is fed from the machine to the bus by means of ____________. a. Brushes on a commentator b. Brushes on a ship rings c. Ship rings on a commentator d. Direct connection from the stator Ans. D 70 209. The frequency of an AC generator is adjusted by means of the ________. a. Main alternator field rheostat b. Exciter field rheostat c. Prime mover governor control d. Equalizing reactor Ans. C 210. H2SO means ______________ a. Sulphuric acid b. Hydrochloric Acid c. Hydraulic Acid d. Muriatic Ans. A 211. One important difference between Y – connected and Delta connected generators is that delta connections have_____________. a. Line voltages equal to the vector sum of the phase voltages b. Phase voltage 90 out of sync c. Line current equal to the phase current d. Line voltage equal to the phase voltage Ans. D 71 212. It is a good practice to have the frequency of the incoming alternator adjusted slightly higher than that of the bus frequency because _________. a. This allows the oncoming-machine to accept load immediately b. This prevent the machine from floating on the line c. The reverse power relay is prevented from activating d. All of these choices Ans. D 213. If two AC generators have been placed in paralleled, the three power load is initially distributed evenly by _______________. a. Balance oil b. Changing field excitation c. Adjusting the generator control settings d. Rheostat Ans. C 214. The KW load can be adjusted on parallel generators by using the ___________. a. Balance coil b. Rheostat c. Field excitation d. Governor control Ans. D 72 215. If the field excitation is suddenly lost as alternator operating in parallel, that alternator will __________. a. Supply excessive current in the bus b. Operate at the same load c. Lose its load and end to over speed d. Become overloaded and stop Ans. C 216. When two AC generators are being paralleled, the breaker should be closed with the Synchroscope pointer rotating in the ______________. a. Slow, clockwise direction, just before 12 o’clock position b. Fast, clockwise direction, just after 12 o’clock position c. Slow, counter clockwise direction after 12 o’clock position d. Fast, counter clockwise direction after 12 o’clock position Ans. A 217. When parallel, AC generators must have the same _________. a. Frequency b. Number of phases c. Phase rotation d. All of these choices Ans. D 73 218. When paralleling two alternators, the synchronizing lamps remain lit as the synchroscope pointer approaches “0”. This indicates the _________. a. Incoming alternator is running too last b. Alternator voltages are 180 apart c. Synchroscope is defective or broken d. Alternator power are in phase Ans. C 219. When paralleling two alternators using three synchronizing lamps, the flicking of all three lamps progressively slower and slower. This means the ___________. a. Frequency of the incoming generator is approaching that of the bus b. Frequency of the incoming generator is less than that of the bus c. Phase rotation of the incoming alternators is opposite that of the bus d. Terminal voltage of the incoming alternator is approaching that of the bus Ans. A 220. Motorizing of an alternator is undesirable _____________ a. Alternator will be damaged b. It puts additional load on the bus c. High voltage pulses are induce in the bus d. All of these choices Ans. B 74 221. When shore power is being connected to a ship in dry-docks __________. a. The ship generator are parallel with shore power to provide continuous power b. Proper phase sequence must be established c. Exactly 450V must be supplied from shore d. Exactly 60Hz must be provided by the terminal Ans. B 222. When two generators are on the line and are sharing the load equally they are said to be operating in ______________. a. Frequency b. Series c. Parallel d. Resonance Ans. C 223. The primary function of an electric motor is to ________. a. Develop torque b. Generate high voltage c. Produce a magnetic field d. Generate high electrical resistance Ans. A 75 224. Any electric motor can be constructed to be _____________. a. Short proof b. Ground proof c. Explosion proof d. Over load proof Ans. C 225. An advantage of DC motors over AC motors is that they ____________. a. Are less expensive b. Require less maintenance c. Can be started across the line d. Offers an effective means of controlling the speed Ans. D 226. The direction of rotation of a DC motors can be reverse by ______________. a. Reversing the field connection b. Reversing the armature connections c. Wiring the field and armature in parallel d. Wiring the field and armature in series Ans. A 76 227. Uneven area of the commutator surface on direct current generators can be caused by ___________. a. Rapid change is load b. Excessive operation at light load c. In correct position of brush d. Unequal pole spacing Ans. C 228. In general, DC motor brush sparkling can be caused by ___________. a. Incorrect brush grade, pressure or position b. Poor brush grade c. Uneven commutator height d. Over speeding motor Ans. A 229. When is it necessary to renew brushes in a DC motor? a. The whole set be replaced b. Only those worn out more than 50% need to be changed c. Only chipped or brittle units need to be replaced d. Lubricate the contact surfaces of brushes Ans. A 77 230. The torque produced by a motor when its shaft will not turn even through rated voltage is applied to the stator is known as ____________. a. Locked rotor torque b. Pullout torque c. Breakdown torque d. Torque margin Ans. A 231. An operating characteristic appearing on the name plate of shipboard AC motor is ______________. a. Type of winding b. Input kW c. Temperature rise d. Locked rotor torque Ans. C 232. The operator of electrical motors keep a constant check on ____________. a. Low loads necessities frequent cleaning b. Exceeding nameplate values shortens useful life c. Energy is wasted if full loading is not utilized d. Power factor correction methods are load dependent Ans. B 78 233. When testing a three circuit electric motor for uses condition, the motor should be stopped because ___________. a. Testing an un-energized circuit presents a hazard to the testing personnel b. A faulty fuse can go undetected with the motor energized c. Reversed polarity of the circuit would be indicated by the voltage tester with the circuit energized d. All of these choices Ans. B 234. Discoloration of the motor bars in a squirrelcage motor is typical evidence of _______. a. Moisture b. Overheating c. Vibration d. All of these choices Ans. B 235. The rotation of a three-phase induction motor can be reverse by _______. a. Interchanging any two of the three line leads to the starter b. Disconnecting any three line leads to the starter c. Switching the shunt field cool leads d. Permanently disconnecting any two of the three line leads to the stator Ans. A 79 236. If a single phase induction motor fails to start, the problem maybe _______. a. An open in the main winding b. A shorted shunt field c. A closed centrifugal switch d. Low voltage input Ans. A 237. A machine that converts mechanical energy into electrical energy by using the principle of magnetic induction is called a ____________. a. Generator b. Pump c. Turbine d. Motor Ans. A 238. Which of the following is NOT classified as a DC Generator according to their excitation methods? a. Series wound b. Shunt wound c. Compound wound d. Squirrel – cage wound Ans. D 80 239. When the current load is more than can be carried by a single generator, the problem may be solved by ___________. a. Paralleling two more generators b. Reducing the load c. Increasing the speed of prime mover d. All of these choices Ans. A 240. When precise speed control and varying load are needed, you should use a/an ________. a. Alternating current generator b. Direct current generator c. Electronic motor d. Electric motor Ans. B 241. In general, the COST of an AC motor as compare to DC motor is that an Ac motor costs _______________. a. Less b. More c. Same d. Slightly more Ans. A 81 242. The key for the rotor an AC motors to run in both synchronous and induction type motor is that their stators must have a/an__________. a. Rotating magnetic field b. Electric source c. Rotating torque d. All of these choices Ans. A 243. The type of Ac motor employed on washing machines, refrigerator, compressors, bunch grinders and pumps is often a/an_____________. a. Induction motor b. Synchronous motor c. DC motor d. Single phase motor Ans. A 244. Amortisseur windings are installed in a synchronous motor to __________. a. Reduce eddy current losses b. Produces a higher power factor c. Provides a means for starting d. Eliminate arcing, between the stator the motor Ans. C 82 245. The multiple prefix “giga” (G) means _________. a. Thousand (10 to the 3rd power) b. Million (10 to the 6th power) c. Billion (10 to the 9th power) d. Trillion (10 to the 12th power) Ans. C 246. The multiple prefix “kilo” means ________. a. Thousand (10 to the 3rd power) b. Million (10 to the 6th power) c. Billion (10 to the 9th power) d. Trillion (10 to the 12th power) Ans. A 247. A motor controller contains three selector push buttons labeled “start”, “jog”, and “stop”. When the “jog” button is pushed, the motors __________. a. Will run continuously after the “jog” button is released b. Will run until the “jog” button is released c. Will not start until both the “jog” and “start” buttons are pushed d. Will not start unless the “stop” button is pushed Ans. B 83 248. A “dead front” switch board is one _____________. a. Without switches on it b. With insulated switches and no exposed terminals c. Without circuit breaker d. Without safely handrails nor rubber mats Ans. B 249. When charging 100 amp hour lead – acid battery ______. a. The temperature of the electrolyte should not be allowed to exceed 90oF b. The charging rate should be no greater than 125% of the battery amp-hour rating c. The source of power charging should be 2.5 volts per cells d. Gassing within the battery decreases when nearing full and it will be necessary to reduce charging current to a law finishing rate. Ans. C 250. When lead – acid batteries are charging, they always give off hydrogen gas that is __________ a. Considered inert b. Highly explosive c. Extremely toxic d. Heavier than air Ans. B 84 251. The specific gravity of the electrolyte in a lead – acid battery is measured _____. a. Gould plate b. Titration plate c. Hydrometer d. Litmus paper test Ans. C 252. Which of the following activities occurs during the charging process of a lead – acid storage battery? a. The specific gravity of the acid increases b. Both plates change chemically to lead sulfate c. The specific gravity of the acid decreases d. Hydrogen gas is absorbed Ans. A 253. Which of the following devices are protected from being motorized by a reverse-power relay? a. Alternator b. Wave guides c. Exciters d. Amplidynes Ans. A 85 254. When a lead-acid battery begins gassing freely while receiving a normal charge, the charging current should ____________. a. Be increased b. Remain unchanged c. Be decrease d. Shut off Ans. C 255. An ammeter reads slightly above “zero” when its leads are disconnected, this a result of ____________. a. Mechanical misalignment of the meter points b. A poor ground for the meter case c. Static electricity in the air d. Resistor inside the meter storing charges Ans. A 256. When an alternator is to remain idle for even a few days ___________. a. Lift the brushes and disconnect the pigtails b. Insulate the collector rings with strips of cardboard c. energize the heater circuit d. Energize the exciter circuit Ans. C 86 257. Proper storage battery maintenance includes _______________. a. Keeping connections tight and casing surfaces clean b. Making sure electrolyte level is below the separator plates c. Insulating the terminals with naval jelly d. Maintaining a high charging rate at all ties Ans. A 258. Part of the insulation of practically all electrical machinery is in the form of organic compounds which contain some amount of ______________. a. Asbestos b. Water c. Fiber d. Plastic Ans. C 259. Due to the operating characteristics of the system, time lag fuses (or dual-element fuses) are necessary for use in _______________ a. Main lighting circuits b. Motor starting circuits c. Emergency lighting circuits d. General alarm circuits Ans. B 87 260. Which of the following materials is a good electrical insulator? a. Wood b. Silver c. Copper d. Gold Ans. A 261. The plates of a NiCad storage battery are made of ______________. a. Potassium hydroxide with a small amount of sulfuric acid b. Lead and lead peroxide c. Silver oxide and lead sulfate d. Combinations of nickel powder and nickel and cadmium salts Ans. D 262. Routine maintenance of ship’s service alternator should include _____________. a. Changing the pedestal bearing insulation yearly b. Megger testing of all rectifying diodes c. Lubricating excitation slip rings d. Periodic cleaning of the air filters or screens Ans. D 88 263. Nickel –cadmium storage batteries are superior to lead-acid batteries because they _________________. a. Put out higher voltages and require no maintenance b. Can remain idle and keep a full charge for a long time c. Need fewer cells in series and use less mounting space d. All of these choices Ans. B 264. Which of the listed ranges represents specific gravity corrected for temperature for the electrolyte of a fully charge portable lead-acid battery? a. 1.100 to 1.150 b. 1.180 to 1.200 c. 1.280 to 1.300 d. 1.750 to 2.000 Ans. C 265. The state of charge of a lead-acid battery is best indicated by the ___________. a. Individual cell voltage b. Ampere-hour capacity c. Electrolyte specific gravity d. Total cell voltage Ans. C 89 266. To test fuses in an energized circuit, you should used a _______. a. Low voltage light bulb b. Megohmmeter c. Voltmeter d. Resistance meter Ans. C 267. The main engine auxiliary blower shall be in this position in order to change – over engine control from engine control room ____________. a. Manual b. Auto c. Remote d. Service Note; Change-over from ECR to Bridge Control Ans. B 268. When engine starting is under control, the starting air feed is halted every time engine revolution reaches _____________. a. Dead slow ahead b. Cut – off setting c. Fuel is supplied d. Engine running in fuel Ans. B 90 269. Every time the auto acceleration and auto deceleration device for main engine for main engine rpm are in service in a vessel fitted with engine speed control program, they are indicated in the control console by _______________. a. “Program in progress “ lamp is “on” b. “Program in auto “ lamp is “on” c. “Program running” lamp is “on” d. “Program running in remote control “ lamp is “on” Ans. A 270. The engine speed acceleration or speed deceleration program at the bridge control console is cancelled ____________. a. By pressing the program by-pass button b. By moving Telegraph handle to a different position c. By moving the telegraph handle to maneuvering speed d. By doing any of these choices Ans. D 271. The rpm of the main engine can do no longer be raised when it reached the below preset limit a. RPM limit b. Speed limit c. Over speed d. Governor limit Ans. A 91 272. To avoid the main engine from being exposed to a prolonged harmful vibrations during maneuvering, a quick RPM passage device is fitted to keep the engine RPM at _____________. a. Below or above the critical speed limit b. Within the critical speed limit c. Operator’s speed option d. Maker’s speed option Ans. A 273. The engine starting fuel setting of the governor is usually set at _____________. a. Dead slow ahead b. Slow ahead c. Half ahead d. None of these choices Ans. D 274. Starting of main engine cannot be started due to interlocking device such as _______. a. Turning gear safety device b. Fuel cut – off device c. Emergency trip device d. All of these choices Ans. D 92 275. Starting of main engine cannot be made when this condition is reached. a. Telegraph lever in “stop” position b. Starting air pressure is at alarm point c. Telegraph lever in ahead/astern position d. All of these choices Ans. D 276. The main engine speed can be gradually accelerated from full maneuvering speed to full navigation speed by using the _________________. a. Load program b. Telegraph handle c. Governor control d. Fuel handle Ans. A 277. The main engine speed can be gradually reduce from navigation full speed to maneuvering speed by using the ____________. a. Load program b. Telegraph handle c. Governor control d. Fuel handle Ans. A 93 278. When the main engine fails to start, the telegraph lever shall be placed at this position before a second starting can be effected. a. Stop b. Run c. Ahead d. Astern Ans. A 279. During normal engine speed (navigation full speed) condition, the fuel can be cut-off instantaneously by pressing the _____________. a. Emergency trip button b. Main engine trip button c. Manual trip button d. All of these choices Ans. B 280. The main engine fuel supply will be automatically cut-off when this condition is reached. a. Over speed b. Main lube oil low. Low pressure c. Camshaft lube oil low, low pressure d. All of these choices Ans. D 94 281. Main engine will automatically slow down when this condition is reached. a. Main engine lube oil pressure low b. Crankcase oil mist density high c. Camshaft lube oil low d. Exhaust gas temperature low Ans. B 282. If the engine is running at the direction opposite of the telegraph transmitter command, this alarm is activated. a. Wrong Speed b. Wrong direction c. Wrong way d. Wrong position Ans. C 283. The alarms in the engine control system are in “repose” when the telegraph is at this position. a. Finish with engine b. Standby engine c. Bridge control d. Engine control Ans. A 95 284. The equipment that provides the monitoring and printing of transmitter positions, date and time, whenever the telegraph transmitter position is changed is called _________. a. Telegraph logger b. Telegraph printer c. Transmitter position logger d. None of these choices Ans. A 285. What color appears to warn the user that the paper needs to be renewed when the amount of thermal paper in the longer reaches near the end? a. Blue b. Red c. Yellow d. Brown Ans. B 286. Which of the following main engine safety device is NOT a start interlock device? a. Fuel cut – off b. M/E trip in operational c. Turning gear disengage d. Control air low Ans. D 96 287. The bridge control simulation safety device test can only be affected when the main engine is at this position. a. Stop b. Ahead c. Astern d. None of these Ans. A 288. In a NAVCO type bridge control system, the speed control of the main engine is not executable from the bridge control console when the electric signal to this device is not normal. a. Electric governor b. Electric telegraph c. Electric control console d. Electric actuator Ans. A 289. At extremely low temperatures, a semiconductor is basically an _____________ a. Conductor b. Insulator c. Electron d. Element Ans. B 97 290. An electron has a ____________. a. Negative charge b. Positive charge C. Neutral charge D. No charge Ans. A 291. The resistance of a semiconductor material compared to the resistance of ceramic or glass material is: a. More b. Less c. Equal d. None of these choices Ans. B 292. The three most common semiconductor devices are: a. Transistor, diodes, ic b. Transistor, pcb, relays c. Transistor, diodes, capacitors d. Transistor, diodes, relay Ans. C 98 293. The cargo pump turbine of generator over speed relay initiates closing of the throttle valve when an excessive centrifugal force or speed causes: a. Spring loads weight to trip a valve hatch b. Spring loaded fly balls actuate a control lever c. Oiled pump develops pressure to open a spring loaded relay valve d. Lube oil control temperature actuates a solenoids valve Ans. C 294. The over speed tripping device installed on an auxiliary turbine is automatically actuated by _______________. a. Applied spring force b. Hydraulic pressure c. High back pressure d. Centrifugal force Ans. D 295. The governor of turbo generator maintains constant speed by oil flow pressure and directly changing the position of governor. a. Throttle valve b. Lever c. Steam chest d. Back pressure Ans. B 99 296. Constant speed governors are normally employed with _____________. a. Generator engines b. Turbines c. Electric motors d. Main engines Ans. A 297. The steady frequency of an alternator attached to a generator engine is maintained by: a. Throttle control mechanism b. Governor with variable speed control c. Governor/nozzle control valve d. Constant speed governor Ans. C 298. When a ship service generator equipped with centrifugal type hydraulic governor load increases, that action will occur in the governor internal mechanism. a. Weight will more inward b. Lifting will have inward c. Pilot valve pushing into the cylinder d. Oil is pumped into the cylinder Ans. C 100 299. If two generator will the same no load speed setting are operated in a parallel, the unit that has lesser speed drop will ___________. a. Get less load b. Get larger share of a load c. Have poor speed control d. Have poor power response Ans. B 300. The portion of the engine speed control has manual positioning but with automatic indexing can be found in a ____________. a. Rheostat b. Governor c. Hand wheel d. Engine telegraph Ans. D 301. When cargo turbine’s governor malfunctions affecting the speed of the unit you should _____________. a. Shutdown the turbine b. Locate the problem c. Make entry into log book d. All of these choices Ans. A 101 302. When will be back pressure trip occur in a cargo pump turbine? a. Oil pressure is too low b. Discharge pressure of pump to high c. Gland leak off is too high d. Exhaust pressure rises above preset limit Ans. D 303. The main throttle valve on a turbine admits steam directly into the _________________. a. Steam chest b. Nozzles c. Blades d. Shaft Ans. A 304. In a diesel engine governor, a mechanical or hydraulic action preventing the overcorrection of the fuel supply is called ______________. a. Stability b. Hunting c. Compensation d. Sensitivity Ans. C 102 305. Rotating flyweights acting against a spring force will provide a simple type of ________. a. Feed water regulator b. Governor c. Safety valve d. Control valve Ans. B 306. A pilot valve and servomotor in a governor are used to __________. a. Create hunting b. Open fuel or steam valve c. Increase speed d. Reduce speed Ans. B 307. A constant speed governor is usually installed on a ________. a. Generator engine b. Cargo pump c. Electric motor d. Wheelhouse Ans. A 103 308. In any governor, there is a small range of speed in which no corrective action occurs. This range is called the governor dead band and is caused by ________. a. Friction in the governor linkage b. Excessively sensitivity c. Compensation adjustment d. Hydraulic pressure Ans. A 309. The fuel injection pumps on a diesel engine are controlled by a linkage system attached to the ____________. a. Governor b. Fuel injector c. Camshaft d. Crankshaft Ans. A 310. Irregular engine speed of a diesel generator engine can be caused by ______. a. High generator load b. Poor fuel viscosity c. Poor fuel injectors d. Big clearance in the fuel linkage Ans. D 104 311. If diesel start but failed to reach normal speed, the cause maybe _________. a. Insufficient fuel supply b. Faulty governor c. Improper fuel pump timing d. All of these choices Ans. D 312. A large, low speed main propulsion diesel engine is operating at rated load and speed while the vessel is in a calm sea. As the sea waves increases, the engine governor maintains the same RPM but the load indicator will show ________. a. Increase in load b. Decrease in load c. Load remains the same d. None of these choices Ans. A 313. When a vessel encounters rough seas but the main propulsion diesel engine is steel set to run at normal load, the operator shall immediately take this action. a. Increase the load limit setting b. Decrease the load limit setting c. Increase engine RPM d. Ignore the situation Ans. B 105 314. The ability of the governor to prevent fluctuations in engine speed is called ________. a. Sensitivity b. Stability c. Promptness d. Speed droop Ans. B 315. What device used to limit engine torque at various engine speed? a. Speed limiting governor b. Variable speed governor c. Constant speed governor d. Load limiting governor Ans. D 316. A change in engine speed is required before a governor is able to make corrective movement of fuel rack. This aspect of governing is commonly expressed as a percent and is known as __________. a. Governor sensitivity b. Governor promptness c. Speed droop d. Isochronous governing Ans. A 106 317. The device that most commonly utilizes the principle of electromagnetic induction is the _________. A. Diode B. Transformer C. Transistor D. Rheostat Ans. B 318. In addition to monitory flame quality, flame scanner are used in combustion ____. A. Stop the fuel from interring the burner upon detect of flame failure B. Secure the force draft in case of flame failure C. Automatically stop the fuel service pump D. Adjust fuel/air ratio for non efficient combustion Ans. A 319. When testing of electrical component on wet metal flat form, what safety precautions you must do? Ans. Use rubber matting 320. What is the frequency of FM Radio? Ans. 88.1 to 107.9 MHz 107 321. If transformer will be connected to a DC source, the transformer will overload at the __________. A. contacts B. secondary coil C.core D.primary winding/coil Ans. D 322. Step-down transformer; A. voltage and current will both be increased B. voltage decrease as current increases C.voltage and current will both be decreased D.voltage increases as current decreases Ans. B 323. Step-up transformer; A. voltage and current will both be decreased B. voltage and current will both be increased C.voltage increase as current decreases D.voltage decreases as current increases Ans. C 324. A device with high input voltage and delivers low output voltage is __________? A. step-up transformer B. primary transformer C.step-down transformer D.secondary transformer Ans. C 108 325. A device with low input voltage and delivers high output voltage is _______? A. primary transformer B. secondary transformer C.step-down transformer D.step-up transformer Ans. D 326. A transformer that uses a single winding for voltage transformation? A. Step-up transformer B. Step-down transformer C.Auto-transformer D.Isolation transformer Ans. C 327. An open coil in a transformer is indicated by? A. ‘Zero’ resistance accompanied by high inductance B. No resistance accompanied by stray inductance C.Infinite resistance in addition to normal inductance D.Infinite resistance and no inductance Ans. D 328. When servicing a battery with electrolyte, be sure to ___________. Ans. wear protection 109 329. Shape of governor gear coupling attached to a high speed/range engine is _________. Ans. cone shape 330. Frequency of A.M. radio __________. Ans. Amplitude modulation or Low band frequency (kilo hertz) 331. Four lamps are connected in parallel in a single circuit. If one of the lamp burns out, the others will __________. A. all go out B. become dimmer C.burn with original intensity D.become brighter Ans. C 332. To properly seat the brush on slip rings you should ___________. A. sand paper B. crocus cloth C.emery cloth D.all of the above Ans. A 110 333. Which of the following materials is recommended for finishing the slip rings after grinding or turning? A. Grade 00 sand paper B. Canvas wiper C.Crocus cloth D.Smooth file Ans. C 334. The most practical method used for resurfacing a ship’s service motor commutator is to _______. A. turn it down in the ship’s lathe B. use a grinding rig C.use a hand stone D.burnish it with commutator stones Ans. B 335. For routine cleaning of commutator, you should apply _______. A. course sand paper in a slow back and forth motion across the commutator slots B. an emery cloth parallel to the axis of the machine C.a canvas wiper to the machine while running D.cotton swabs between the commutator bars Ans. C 111 336. A full wave rectifier has one diode burned out in an open condition. What will be the output characteristic of the device? A. Zero B. Half-wave rectified C.Full-wave rectified D.Equal to AC input Ans. B 337. One diode of a full wave rectifier has burned out in a shorted condition. Therefore, the output will be ________. A. zero B. half-wave rectified C.full-wave rectified D.equal to AC input Ans. D 338. Sound pressure is measured in decibels (d13). The healthy human ear can hear frequencies ranging from ________. A. 20-20,000 Hz B. 100,000-200,000 Hz C.200,000 Hz = 1 MHz D.1 MHz-20 MHz Ans. A 112 339. Compressed air should not be used to clean motor controller because ____________. a. it may force metallic particles into coil insulation b. the air blast dries out insulation quickly c. the air mask and respirator would be required Ans. A 340. The removal of paint from electrical equipment, such as generator, should cautiously undertaken because ________________. a. the paint dust is composed of abrasive and semi-conducting materials which impair insulation b. the mechanical shock of paint removal lessens the dielectric strength of the insulation c. paint dust build up has a tendency to cause corrosion d. phase windings frequently become isolated from each other due to dust interference at the terminals Ans. A 113 341. Before working on an electric cargo winch master switch or controller, you should ______. a. open the circuit breaker in the power supply and tag b. spray the gasket surface with solvent c. drain condensate from the box d. heat the switch box to remove any moisture Ans. A 342. Which of the following statements represents the FIRST precaution to be taken prior to working on any installed electrical component. a. open the supply circuits and tag the switch b. wear rubber gloves and boots c. use only approved non-conducting tools d. ground the case of the machine before beginning any repair Ans. A 343. Before any work on electronic and electrical equipment is performed, which of the following precaution should be carried out _____________. a. secure and tag the supply circuit breaker in the open position b. de-energize the applicable switchboard bus. c. By-pass the interlock d. Station a man at the circuit supply switch Ans. A 114 344. Capacitors are used on the output of the power supply in today’s console to _________. a. filter out ripples b. prevent overloads c. act as a permanent load d. decrease the average value of the output voltage Ans. A 345. Which of the spaces listed in defined as a location requiring an exceptional degree of protection when considering the installation of shipboard electrical equipment? a. machinery spaces b. chart room c. console room d. accommodation space Ans. A 346. Which of the listed precaution should be taken when cleaning the internal of a motor with compressed AIR. a. open the machine with both ends so as to allow the air and dust to escape b. be certain that the circuit breaker is open and tagged on the feeder panel c. be certain that the air is clean and dry as possible d. all of the above Ans. D 115 347. Which of the following represent the accepted method of cleaning dust and foreign particles from electrical equipment while limiting damage to electric component. a. using a vacuum cleaner to remove debris from the component b. carefully wiping off the component with a soft cotton rag c. blowing a high velocity stream of compressed air rapidly across the component d. using carbon tetrachloride as a cleaning solvent to clean the components Ans. A 348. Which of the following electric motor would be the safest and most reliable to use on the main deck of a vessel in foul weather condition. a. seal motor b. drip proof motor c. enclosed motor d. watertight motor Ans. D 116 349. In addition to testing the calibration of a circuit breaker, maintenance should include all of the following EXCEPT _______. a. changing out of magnetic and thermal heaters yearly b. checking for corrosion, accumulation of dirt and thermal fatigue c. inspecting for loose or missing parts d. making sure foreign matter does not block tripping element Ans. A 350. When maintenance personnel are working on electrical equipment, all supply switches should be secure in the open position and tagged specially by the ___________. a. watch engineer b. chief engineer or first engineer c. chief electrician d. person performing the repair Ans. D 351. What is the approximate voltage produced by a NICKEL- CADMIUM battery cell. a. 1.25v b. 1.5v c. 2.20v d. 6.05v Ans. A 117 352. A diesel driven emergency generator is prevented from being parallel with the ship’s service generators by ________. a. an electrical interlock system b. an automatic paralleling trip switch c. the synchronizing oscilloscope d. the reverse current relay Ans. A 353. The air gap provided in induction motors should be checked periodically with a feeler gage to detect an unequal air gap and _________. a. decreased motor magnetizing current b. hysteresis losses c. increased power factor d. mechanical damage to the rotor Ans. D 354. Which of the following problems is indicated if a lead acid battery begins to gas violently when it is first placed on charge? a. insufficient compartment ventilation is being provided b. a short circuit exists in one of the battery cells c. the battery is undergoing its normal charging rate d. an excessive charging rate is being applied to the battery Ans. D 118 355. Complete maintenance of electric motors should include periodic check for machine __________. a. Vibration b. Water tight integrity c. Speed droop d. Reactive power Ans. A 356. Which of the listed fire extinguishing agents would be suitable for use on an oil fire (Class B), but dangerous on an electrical fire? a. Co2 b. Water fog / spray c. Halon d. Dry chemical Ans. B 357. Which of the following causes electric static forces? a. Shampooing b. Rubbing c. Exercise Ans. B 119 358. Regarding battery charging room’s ventilation should be provided __________. a. At the lowest points of the room b. Horizontally near the batteries c. At the highest point of the room d. Only when charging is in progress Ans. C 359. Two 100 watt light bulbs are connected in parallel across a 100 volt power supply. The total power developed in the circuit is __________. a. 200 watts b. 100 watts c. 50 watts d. equal to the product of the amperes times the voltage in each branch Ans. A Solution: PT = P1 + P2 PT = 100 w + 100 w = 200 w 360. Which substance listed should be applied to battery terminals to help prevent corrosion? a. Zinc chromate b. Lead hydroxide c. Naval jelly d. Petroleum jelly Ans. D 120 361. When a lead acid battery explodes, what is the direction of explosion? a. Side ways b. Upwards/top c. Downward d. In all direction Ans. B 362. Prior to starting an AC generator prime mover, the voltage regulator cutout switch should be placed in the ________. a. manual position b. bus neutral position c. raise voltage position d. transfer position Ans. A 363. Automatic voltage regulators functions to ________. I – Compensate the current II – Compensate the voltage III – Filter out ripples a. I only b. II only c. III only 121 d. I, II & III Ans. D 364. Atoms with equal/same numbers of electrons and protons is referred to as ________. a. equal b. balance c. neutral d. unbalance Ans. C 365. A circuit breaker for a 300 kw alternator is rated at 470 amperes of full continuous load. The amount of overcurrent allowed is 125%. Which of the following conditions will trip the breaker? a. Sustained current flow of 470 amperes b. Sustained current flow of 500 amperes for 10 minutes c. Momentary starting load of 550 amperes d. Sustained current flow of 590 amperes Ans. D 366. After rubbing a glass rod and fur, it will become _______. a. heated b. electrified c. fused together d. no reaction Ans. B 122 367. What electrical component that covers the junction box, fuse box, switch box etc? a. Circuit breaker b. Power supply c. Cover d. Capacitor Ans. B 368. Which of the following statement is true regarding electric receptacle outlets? a. Sufficient number of receptacle outlets in the crew accommodation for an adequate level of habitability b. Each receptacle outlet must be compatible with the voltage and current of the circuit c. A receptacle outlet must not have any exposed live parts d. All of the above Ans. D 369. Which of the following statements is/are true regarding requirements for receptacle outlets aboard vessels? a. Each receptacle outlet operating at 100 volts or more just have a grounding pole b. Outlets connecting a lifeboat and the vessel electrical system must have threaded plug 123 c. Machinery space must contain sufficient outlets for lighting all machinery with a portable light having a 50 ft flexible cord d. All of the above Ans. A 370. An ohmmeter can be used to measure _______. A. current flow in circuit B. voltage between two points in a circuit C.circuit continuity D.power Ans. C 371. Increasing the load on an engine equipped with a constant speed mechanical governor, will cause the engine speed to initially ________. A. increase B. decrease C.fluctuate D.remain constant Ans. B 372. Which of the listed sections of an emergency switchboard is used to supply power for alarm signals under emergency conditions? A. The generator and bus transfer section B. The 450 volt, 60 cycle, 3 phase bus C.The 120 volt, 3 phase, 60 cycle bus D.The 24 volt DC bus Ans. D 124 373. Grease coatings on electrical contact surfaces increase contact resistance and should be removed with a/an _______. A. small wire brush B. compressed air jet C.clean dry cloth D.10% solution carbon solvent and water Ans. C 374. If a transformer is connected to a DC source, the transformer will overload at the _______. A. contacts B. primary coil C.secondary coil D.core Ans. B 375. In a 60 Hz AC system, the current will pass through one completes cycle in __________. a. 60 seconds b. 6 seconds c. 7 seconds d. 0.016 second Ans. D 125 376. The mica used in the commulators of DC machinery is _________. a. harder than copper b. softer than copper c. the same hardness the copper d. softer than copper but wears away at a slower rate Ans. A 377. Voltage will always ________________. lead current in a/an a. capacitive circuit b. inductive circuit c. magnetic circuit d. resistive circuit Ans. B 378. A burned-out “LED” should be indicated by _______________. a. Excessive output b. A slight glow in the crystal c. Excessive illumination d. No illumination Ans. D 126 379. When discharging fuses and the spring clips are found to have lost their grip, they should be replaced or _______________. a. tightened firmly with insulated pliers b. clip clamps should be used c. wired closed with uninsulated varnished copper wire d. carefully bent back to their original shapes Ans. B 380. A shore circuit breaker should be closed only ___________. a. when the ship’s generators have been directly paralleled to those on shore b. when the ship’s generator have been removed from the bus c. exactly 450 volts must be supplied from the shore d. exactly 60Hz must be provided by the terminal Ans. B 381. The instantaneous reduction in voltage of an AC generator, resulting from an increase in load and prior to the automatic voltage regulator correcting the situation, is called voltage _______________. a. droop b. drop c. dip d. regulation 127 Ans. C 382. In a hollow glass or clean plastic cylinder – type fuse design the glass or clear plastic case allows a visual check if the fuse is_________? a. Blown b. Clean c. Dirty d. Charge Ans. A 383. In a rectifier with capacitor , the current though the load is supplied by the capacitor when the diode is_________? A . Cut – off B. “On” C. Neutral D. None of these choices Ans. C 384. USCG Regulation 46 CRF require the emergency lighting and power system__? a. Must be tested under load from emergency generator before sailing b. Must be tested & inspected weekly & the date recorder c. Batteries must be tested annually & he date recorded d. Must be capable of sustaining the emergency load for 48 hours 128 Ans. B 385. When working on electrical circuits containing large capacitors, in addition to de- energizing the circuit , which of the listed precautions should also taken? a. Ground the capacitor terminals b. Check capacitor circuit polarity c. Keep all radio equipment away d. Measure capacitor insulation resistance Ans. A 386. If both “high level” and “ low level” alarms come on the same address of a centralized control console , the most likely problem is a/an------? a. Failed alarm b. Extremely low level c. Sensor failure d. Extremely high level Ans. C 387. The output of a rectifier is a ________? a. Pulsating DC current b. Pulsating signal current c. Pulsating DC voltage d. Pulsating DC ampere Ans. B 129 388. Defects in wiring permit current to jump from one wire to another before the intended path has been completed are called______. a. grounds b. shorts c. break d. open Ans. B 389. In an unmanned main engine, an engine failure occurs. An audible alarm is indicated or located in the_____________. I - at each station II - C/E cabin III - Navigating bridge A. I, II & III B. I only C.II only D.III only Ans. A 390. Magnetic fluxes are lines of force of the magnet that travel from_____. A. North to South pole B. south to North pole C. Positive to Negative bodies D. Negative to positive bodies Ans. A 130 391. Whenever an atom losses an electron (-) charge and has an overall positive (+) charge, it became______. A. cation B. anion C.anode D.cathode OR A. positive ion B. lighter C. moves faster D. moves slower Ans. A 392. Who operate the machine____. A. Fitter B. Chief Engineer C.Master D.Operator Ans. D 393. As a result of a mechanical malfunction in one of the ships service generators operating in parallel , you must secure that generator. In order to prevent a possible overload, to the remaining generator, which of the following sequential courses of action should be taken _________. A. Trip all non-vital distribution feeder circuit breakers , the malfunctioning generator’s circuit breaker, & the prime mover throttle trip 131 B. Trip the malfunctioning generators circuit breaker and prime mover throttle trip. C.Trip the malfunctioning generator’s circuit breaker and distribution feeder circuit breakers Ans. A 394. Non-adjustable molded case circuit breakers and classified by frame size, ampere rating and interruption capacity. The frame size is expressed in______. A. Degree centigrade B. Circular mills C. Amperes D. Volts Ans. C 395. D/C motor & generator commutator is made of ________. A. Copper segments insulated from each other with hardened mica B. Copper Segments insulated with soft mica Ans. A 396. Time delayed or delayed action fuses are designed to_______. A. prevent ground in branch circuit B. prevent an open in motor circuit C.permit momentary overload without melting D.guard lighting & electric circuit Ans. C 132 397. Which of the listed procedures is the best way to tell if a motor become overload? A. Measure the current flow & compare it with the motor full load current flow as shown on the nameplate B. Feel the motor & judge by the temperature C.Watch for signs of smoke coming from the motor D.If the installation is properly designed, there is no cause for overload Ans. A 398. Which of the listed faults cannot be eliminated, EXCEPT by turning or grinding a commutator with a rigidly supported tool? A. Sparking brushes B. Eccentricity C. High mica D. Blackened commutator Ans. B 399. The most inefficient method of voltage reduction, from the standpoint of power loss, even when placed in series with the load, is the use of a/an __________. A. Resistor B. Inductor C. Capacitor D. Transistor Ans. A 133 400. A spring-loaded centrifugal flyweight governor response to reduced engine load with an immediate increase ________. A. pilot valve oil pressure B. speeder spring force C. compensation needle valve clearance D. centrifugal force on the flyweight Ans. D 401. One circular mil is ________. A. 1/10 inch B. 1/1000 inch C. 1/100 inch D. 1/100,000 inch Ans. B 402. One mil is _________. A. 0.10 inch B. 0.01 inch C. 0.001 inch D. 1.000 inch Ans. C 134 403. Which of the following represents a characteristics of an UNGROUNDED electrical distribution system? A. Accidental contact between one line and ground des not cause an outage B. Double ground faults on different phases will not cause an outage C.Ground detection system are unnecessary D.Accidental contact between one line and ground will always cause an outage Ans. A 404. When securing the AC generator, you should FIRST. A. Open the generator circuit breaker B. Switch to voltage regulator to “manual” C.Decrease the field excitation to minimum D.Reduce the load on the unit Ans. D 405. The purpose of UNDER VOLTAGE protection device is to _________. A. prevent high armature current when power is restored B. start the motor at a very low voltage C. trip the load off the motor in case of fire D. protect personnel from low voltage shock Ans. A 135 406. A low-voltage protection circuit is used in electric motor starting equipment to __________. A. allow the motor to restart automatically on restoration of voltage without manually reseating B. prevent the motor from re-starting automatically on restoration of voltage Ans. B 407. Inductance is the property of an electric circuit that _________. A. Opposes any change in the applied voltage B. Opposes any change in the currents flow through the circuit Ans. B 408. As a general rule, the first trouble-shooting action to be taken in checking faulty electric control device is to ___________. A. draw a one line diagram of the circuitry B. test all fuses and measure the line voltage C. take megger reading D. insulate the apparatus from ground Ans. B 136 409. Varying the FREQUENCY OF TURBO GENERATOR by means of adjusting the _________. A. generator exciter field B. governor control Ans. B 410. A delayed-action fused is most frequently used in which of the listed circuit ____. A. lighting circuit B. motor circuit C. electric heater circuit D. radar circuit Ans. B 411. When the insulating breaks down within a metal encased, portable, electric tool ______? A. Line voltage may be place in the tool casing making it dangerous to operate B. You should stand on a grounded deck plate before energizing the tool Ans. A 412. When trouble shooting an alkaline storage battery, a weak or dead cell is best located by____. a. Checking the specific gravity of each cell b. Visually inspecting each cell’s electrolyte level c. Testing each cell with a VOLTMETER d. Measuring the electrolyte temperature with accurate mercury thermometer 137 ANS. C 413. If the SPEEDER SPRING of the main propulsion diesel engine GOVERNOR BREAKS while operating at full-load, the engine RPM will______. a. Increase until the overspeed trip actuated b. Hunt until stabilized by the droop rod c. Decrease to a slightly lower value d. Remain the same until manually changed ANS. C 414. To prevent interference between the various radio and TV station, each station is assigned its own frequency. AM broadcast stations operates at frequencies in the range of_________. a. 535 kHz to 1605 kHz b. 25 kHz to 135 kHz ANS. A 415. Upon failure of the normal power supply, the emergency generator is placed on the line by the __________. A. main bus feeder B. automatic bus transfer device C.line connection feeder D.power failure alarm bus Ans. B 138 416. In a simple mechanical governor, the ____. A. centrifugal force rotates the ball-head B. flyweight centrifugal force is balanced by spring force C.flyweight centrifugal force is balanced by hydraulic pressure D.speeder spring alone actuates the fuel control rod Ans. B 417. The type of control circuit that will NOT permit automatic restarting after power is restored, following a power failure is called ______. A. low voltage protection B. low voltage release C.overload lockout D.reduce voltage restart Ans. A 418. Which of the listed feature does the Coast Guard Regulations require of a motor controller which must be manually restarted following a power failure? A. Overload protection B. Low voltage release C.Low voltage protection D.Reverse current protection Ans. C 139 419. The type of feature afforded auxiliaries vital to the operation of propelling equipment, where automatic restart after a voltage failure would not create a hazard, is termed _______. A. low voltage protection B. high amperage protection C.low voltage release D.high amperage release Ans. C 420. Which of the listed items will stop a motor due to a reduction in voltage and restart it when the voltage is restored to normal _______. A. low voltage protection circuit B. non-renewable link fuse C.renewable link fuse D.low voltage release circuit Ans. D 421. In half-wave rectifier can use with or without _______. A. diode B. capacitor C.transformer D.resistor Ans. C 422. What is NOT part of maintenance work on brushes and commutator? 140 A. Apply coat of mineral oil/solvent B. Replace worn brushes Ans. A 423. Which of the damages listed can occur to the components of a winch master control switch, if the cover gasket becomes deteriorated? A. Overheating of the winch motor B. Contamination of lube oil C. Sparking at the winch motor brushes D. Rapid corrosion of switch components Ans. D The full torque electric brake on an electric cargo 426. winch functions to ___. a. act as a backup brake in case the mechanical brake should fail b. automatically hold the load as seen as current to the machine is shut off c. automatically reduce lowering speed d. automatically reduce hoisting speed Ans. B 427. Moisture damage due to consideration inside the 141 cargo winch master switches can be reduced by _____________. a. installing light bulb in the pedestal stand b. sealing the switchbox c. venting the switchbox regularly d. using strip heaters inside the switch box Ans. D In the event of a power failure during cargo 428. loading operations, the movement of an electric powered cargo will be stopped by ______. a. manual override switch b. spring set brake c. hand-operated brake d. weight of the boom load Ans. B The greatest enemy of an idle electrical 429. equipment such as a pump room fan motor is the _____________. a. loss of magnetism b. moisture in the insulation c. insulation varnish flaking d. dirt accumulation on the windings Ans. B Which of the following represents the best method 430. of cleaning dust from electrical circuits in order 142 to limit damage to electronic components? a. wipe off with soft cotton rag b. use high velocity compressed air c. use vacuum cleaner d. use chemical solvent Ans. C In an induction motor, rotor currents are circulated 431. in the rotor by ____. a. slip ring and brushes b. armature and brushes c. inductive reaction of rotating stator field d. external variable resistor Ans. C A circuit breaker and a fuse have basic similarity 432. in that they both ____. a. can be reset to energize the circuit b. should open the circuit when overload develops c. will burn out when overload develops d. all of these choices Ans. B Electrical leads and insulation on a motor should 433. be painted with ___. 143 a. heat resisting acrylic b. heat resistant aluminum c. insulating varnish d. insulating white lead Ans. C A degree of control over speed of slip ring 434. induction motor can be obtained by _______. a. adjusting governor linkage b. changing the number of coils on the motor c. inserting assistance to the stator d. inserting resistance to the rotor Ans. D A circuit breaker differs from a fuse because a 435. circuit breaker can ___. a. melt and be replaced b. enclosed tube has insulating material c. gives no visual condition d. trips to break the circuit and my be reset Ans. D The main purpose of an auxiliary windings as a 436. split-phase, single-phase motor is to____. a. limit the starting voltage b. increase starting current c. start the motor d. keep the motor running Ans. C The state of charge of a lead acid storage battery 437. is best indicated by _____________. 144 a. testing individual cell voltages b. ampere hour capacity c. specific gravity of electrolyte d. total cell voltage Ans. C A low voltage source is being used for testing 438. armature coils. A short circuit will be indicated by a _____________. a. high voltage reading b. zero or low voltage reading c. fluctuating voltmeter reading d. steady voltmeter reading Ans. B Which of the listed procedures should be carried 439. out to prevent moisture damage to idled electrical apparatus? a. inert the space b. strap silica gel c. place heat lamps d. cover the equipment with canvass Ans. C 145 Electric heaters are used in motor controllers to 440. _____________. a. prevent movable contacts from freezing b. keep components warm c. prevent condensation of moisture d. maintain good resistance of circuit Ans. C A fuse that blows often should be replaced only 441. with fuse of _______. a. recommended current and rating b. higher current and rating c. lower current and rating d. none of these choices Ans. A Which of the listed precautions should be 442. observed before spraying liquid solvent on the insulation of an electric motor? a. slow the motor down to low speed b. disconnect the motor from the power source c. secure all ventilation in the area d. pre-heat the insulation Ans. B 146 On a tanker vessel with electrically driven 443. capstan, the motor should be megged periodically to test _____________. a. insulation resistance b. eddy currents c. capacitance d. armature reactance Ans. A A reverse power current relay prevents AC 444. generator motorization automatically by ___. a. transferring the load b. speed up the prime mover c. secure the exciter generator d. tripping the circuit breaker Ans. D Which of the following devices will prevent an AC 445. generator from becoming motorized? a. overcurrent relay b. relay trip c. governor control switch d. reverse current relay OR a. Overspeed trip b. back pressure trip c. Governor control d. Reverse power relay Ans. D 446. A grounded switch or cable will be indicated by a megohmeter of _____________. 147 a. infinity b. zero c. unsteady reading in high range d. unsteady reading in low range Ans. B Batteries used for diesel engine starting should 447. _____________. a. be located in a locker on the weather deck b. be located as close as possible to the engine c. have capacity to start the engine up to 50 times d. none of these choices Ans. B Before testing insulation with a megohmeter, the 448. windings of large machines should be grounded for 15 minutes because ___________. a. static charge in the machine may give false reading b. insulation may get damaged c. insulation may be wet d. machine may run automatically Ans. A 148 Battery charging rooms should be well-ventilated 449. because the charging process _____. a. produces highly poisonous hydrogen b. produces highly combustible oxygen c. liberates explosive gases d. liberates corrosive gases Ans. C When a megger is used to test insulation, the 450. gradual rise of the pointer reading as a result of continued cranking, is caused by ___________. a. good resistance b. leakage in the winding c. inductive resistance in windings d. dielectric-absorption effect of the insulation Ans. D Most 3-phase induction motors for driving engine 451. room auxiliaries are started by ______. a. resistor starters b. across-the-line starters c. impedance starters d. reactor starters Ans. B First aid treatment for battery acid or alkali burns, 452. especially in the eyes, includes ______. 149 a. flushing with large amounts of fresh water b. wiping the affected area with clean dry cloth c. using talcum powder to counter itching d. all of these choices Ans. A 453. A hydrometer is used to measure __________. a. specific gravity of battery electrolyte b. water pressure on deck line c. amount of distilled water evaporator produced d. power developed by sea water service pump Ans. A Discharge switches are often located on hand454. driven meggers. The purpose of these switches is to discharge capacitive charges stored in the _______________. a. megger hand generator b. movement coils c. tested equipment while conducting test d. tested equipment after conducting test Ans. D 150 455. A megohmmeter can be used to test for ______. a. an open field b. synchronous speed c. frequency d. high voltage presence Ans. A You are attempting to parallel two AC generator 456. and the synchroscope pointer is revolving slowly in the fast direction. You should ________. a. use the governor switch to adjust incoming voltage so it is equal to the voltage b. use the governor switch to increase the speed of the prime mover c. close the circuit breaker when the synchroscope pointer approaches “0” position d. close the circuit breaker when the synchroscope pointer approaches “180” position Ans. C A fuse will blow for all the listed reasons except 457. _____________. a. excessive vibration b. extremely hot surroundings c. loose fuse clips d. low contact resistance within the fuse Ans. D 458. Moisture absorbed in the windings or condensed 151 on the surface of electrical machinery insulation _____________. a. is good for the machinery as additional insulation b. lowers insulation value and may create grounds c. enhance insulation value of the machine d. reduce the amount of current to be fed to the machine Ans. B In which of the situation listed will a 459. megohmmeter give the most accurate reading ? a. while the machine is in operation b. while the machine is about to stop operation c. immediately after the machine has stopped d. 15 minutes after the machine has been isolated and grounded Ans. D When using a multimeter for resistance 460. measurements, it should be calibrated by clipping the loose ends of the leads together and ____. a. setting the instrument pointer at zero ohms b. adjusting the line voltage to calibrate the instrument c. plugging each end of one test lead into the plus and minus terminals d. using special purpose resistance measuring 152 instruments Ans. A Which of the following insulation will deteriorate 461. first as a result of heat generated in the conductor it surrounds ? a. rubber b. varnished cloth c. silicon d. asbestos Ans. A 462. A multimeter can be used to measure _______. a. resistance b. voltage c. current d. all of these choices Ans. D Which of the following problems will most likely 463. occur if the starting winding of a split-phase induction motor failed to cut-out once the motor was in continuous operation? a. the motor will overspeed b. the motor will run at a reduced speed c. the motor will stop d. the winding will burn out 153 Ans. D When insulation failure produces a low resistance 464. current path between two conductors, the resulting condition is known as _____________. a. an open circuit b. a short circuit c. a ground d. a surge Ans. B When disassembling motor for maintenance or 465. overhaul _________. a. punch mark frame and end bells for proper assembly b. wrap bearings in lint free cloth if they are to be reversed c. tag and store small parts in a box d. all of these choices Ans. D 466. Fuses are usually rated in _____________. a. watts b. amps only c. volts only d. amps and volts Ans. D 467. When used for taking resistance measurements, 154 voltage-ohmmeter is normally paired by ______. a. a hand cranked generator b. internal storage batteries c. the current in the circuit being tested d. a step-down transformer Ans. B When an AC or DC motor fails to start, the FIRST 468. step in troubleshooting should be to check the _____________. a. motor windings for obvious opens b. motor controller leads for continuity c. fuse or circuit breaker d. motor controller leads to ground Ans. C A current-carrying conductor making electrical 469. contact with a wiring conduit will be indicated by a _____________. a. high switchboard wattmeter reading b. totally dark switchboard ground detecting light c. low switchboard wattmeter reading d. all of these choices 155 Ans. B To remove an alternator operating in parallel with 470. mother unit from the main electrical bus, you must FIRST _____________. a. adjust the power factor on both units b. set the desired voltage on the outgoing alternator c. open the circuit breaker on the outgoing alternator d. remove the load from the outgoing alternator Ans. D When testing for blown fuses in a three-phase 471. supply circuit to a motor, you should first ______. a. apply the megger across the tops of the line fuses b. apply the megger across the bottom of the line fuses c. apply the voltage faster across the bottom of the line fuses d. de-energize the circuit and then use a continuity tester Ans. D In a three-phase electrical system, three ground 472. detecting lamps are provided. If all three lamps REMAIN at half brilliance when the ground detecting switch is operated ______. a. there is a slight ground on all three phases b. the switch must be replaced c. there are no grounds present d. the light bulbs are of improper voltage 156 Ans. C Electrical failures in motors are caused by the 473. breakdown of insulation, which maybe caused by ______. a. penetration of moisture b. accumulation of dirt c. overheating d. all of these choices Ans. D In order to safely carry out repairs to a generator 474. circuit breaker, it must be isolated from the bus. This is accomplished by opening the ________. a. reverse power relay b. bus disconnect link c. generator bus fuse connection d. power directional relay Ans. B If the voltage supplied to the lightning circuit is 475. 110 volts. How much current is used by a 100 watt light bulb ? a. 0.08 amps b. 0.91 amps c. 1.10 amps d. 90.9 amps Ans. B 157 According to USCG regulation (CFR 46) which of 476. the ff systems must be arranged so as to be energized by emergency power supply in case of power failure? a. at least one light is steering gear room b. each power operated watertight door system c. each changing panel for temporary emergency batteries d. all of these choices Ans. D Diesel generator # 1 & 2 are operating in parallel 477. at near full load capacity. Diesel generator # 1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions properly and trips generator # 1 off the board. Which of the following should you do FIRST? a. start the standby generator b. ascertain cause of low lube oil pressure c. strip the board of non-vital loads d. secure alarm, reset all tripped relays and restart generator # 1 Ans. C The source of emergency lightning and power at 478. loss of normal-ship’s power on a cargo vessel should be obtained from the _____________. a. emergency switchboard b. main switchboard c. emergency batteries d. emergency power from main switchboard 158 Ans. A International regulations states that continuous 479. trickle charge supplied from the ship’s required service power system, is for batteries supplying power to the __________. a. emergency diesel starting system b. emergency power system for radar c. emergency power system for steering gear d. emergency power system for lifeboat radios Ans. A According to USCG Regulation 46CFR, the 480. talking and calling circuits of a sound powered telephone system must be __________. a. intrinsically safe b. independent of each other c. independently grounded d. connect to a common ground Ans. B Which of the listed safety features should be 481. provided in a small room or locker where batteries are stored? a. install a CO2 system b. install an exhaust system fan c. an exhaust duct to be made 3 feet above the deck d. exhaust duct is to be provided from the top of 159 the locker to open air Ans. D You should not allow salt water to enter a lead 482. acid battery or come in contact with sulfuric acid because _____________. a. resulting gas is extremely flammable b. the resulting gas is a respiratory irritant that can be fatal c. the primary constituent, sodium, reacts lethally with lead peroxide d. continuing salt water with lead acid creates a harmful gas Ans. B Which of the ff should be done when a 10 amp 483. blown fuse is replaced ? a. short out the fuse b. replace blown fuse with less than 10 amp rating c. replace blown fuse with exactly 10 amp rating d. none of these choices Ans. C International Regulations requires that an 484. indicating light at the propulsion control station will activate if overloading or overheating occurs in a ____________. a. forced draft fan b. steering gear motor 160 c. fuel pump motor d. condensate pump motor Ans. B International regulations requires that a remote 485. stop/start button for engine room bilge pump shall be located at _____________. a. main deck / upper deck b. emergency generator room c. engine control room d. cargo control room Ans. A International regulations requires a continuous 486. trickle charge is to be applied from the ship’s service power system for batteries supplying power to the ___________. a. emergency power for bridge and engine control rooms b. portable radios fro the lifeboat c. emergency power and lightings d. all of the above Ans. C A multimeter may be damaged by taking a 487. _____________. a. voltage reading while in the resistance mode b. current reading while in voltmeter mode c. resistance reading while in the ammeter mode 161 d. resistance reading while in the voltmeter mode Ans. A 488. When replacing fuses, always make sure _____. a. to stand on a rubber mat and use rubber gloves b. to use insulated pliers or screwdrivers c. the fuse clips are straight, tight and holding the new fuses well d. to increase the fuse rating by 1-% to guard against “nuisance” blowing Ans. C If all the grounds lamps burn with equal brilliance, 489. whether the test button is depressed and released, which of the listed conditions is indicated? a. no ground exist b. all three phases are grounded c. the test switch is faulty d. the current transformers are shorted out Ans. A The ground indicating light on the main 490. switchboard is indicating a ground. The last procedure for locating the grounded circuit is to ____________. a. trace the circuit’s paths while looking for burned spots b. open the circuit breakers on the distribution 162 panel one by one until the lights no longer indicate a ground c. check circuits for continuity d. none of these choices Ans. B 491. An ohmmeter can be used to test for ________. a. an open field coil b. a shorted field pole c. reverse polarity d. low voltage supply Ans. A Electrical machinery insulation will breakdown 492. more rapidly due to ________. a. low loading of motor and generators b. frequent megger testing c. high temperature and vibration d. high operating frequencies Ans. C Low horsepower, poly-phase conduction motors 493. can be started with full voltage by means of _____________. a. compensator starters b. auto transformer starters c. across the line starters d. primary resistor starters 163 Ans. C Which of the following conditions will occur if the 494. solenoid coil burns out on a cargo winch with an electric brake ? a. the brake will be set by spring force b. the motor will overspeed and burn out c. the load suspended from the cargo boom will fall d. none of these choices Ans. A External shunts are sometimes used with 495. ammeters to _____________. a. increase meter sensitivity b. prevent shunts with larger resistance to be utilized c. prevent damage to the meter movement from heat generated by the shunt d. enable the construction of a compact meter with a virtually unlimited range Ans. C Which of the following statements is correct in the 496. maintenance of contacts in relays ? a. they should dressed with wire wheel b. they should be dressed w/ fine cut file if surface is uneven c. if burns are noticed, at should be removed w/ 164 sandpaper d. should be held together with every paper driven between contacts Ans. B A signal derived from a controlled function and 497. returned to the initiating point is called a/an _____________. a. monitoring signal b. inverse signal c. reverse signal d. feedback signal Ans. D A device which prints out a permanent record of 498. the plant operating conditions is known as the _____________. a. analog logger b. bell book c. alarm logger d. data logger Ans. D The speed of squirrel cage induction motor is 499. determined by the _______. a. diameter of the stator b. no. of stator poles c. rotor winding resistance d. stator winding resistance 165 Ans. B Under which of the listed conditions can the 500. engine room retake the throttle control from the bridge ? a. anytime it deemed necessary b. only w/ master’s permission c. after 10 min. delay to the command d. only when the throttle is at stop Ans. A A generator has been exposed to water and is 501. being checked for its safe operation. Therefore it is necessary to ________. a. check for shorted coils b. take moisture reading c. test insulation reading d. ground the commutator and run it for half an hour Ans. C A squirrel-cage motor is designed to have 502. _____________. a. low starting voltage b. low starting current c. high starting voltage d. low starting resistance 166 Ans. B In a DC series circuit, all the conductors have the 503. same _____________. a. power consumption b. voltage drop across c. current passing thru them d. resistance passing thru them Ans. C Which of the AWG wire sizes listed below would 504. have the smallest diameter ? a. 000 b. 0 c. 12 d. 250 Ans. C When using a megger to test insulation, good 505. insulation will be indicated by ______. a. slight kick of the needle downscale b. downward dip followed by gradual climb to the true resistance value c. initial dip of pointer d. gradual rise in the pointer Ans. B A reverse-current relay will prevent DC generator 506. motorization by _______. a. automatically redirecting the load b. automatically speeding up the prime mover c. tripping the panel board main switch d. tripping the generator circuit breaker 167 Ans. D If many turns of an alternating current coil 507. contractor become short circuited, the coil ___. a. temperature will drop b. will probably burn out completely c. will continue to operate d. will operate on reduced current Ans. B How is a wattmeter electrically connected in a 508. circuit ? a. in series b. in parallel c. in series-parallel d. inductively Ans. C Which of the listed conditions would indicate the 509. need for cleaning electrical insulation ? a. low ambient temperature b. low operating temperature c. high dielectric strength d. low megger readings Ans. D Multiple grounds have developed and were 510. initially indicated by the ground detecting system as one ground. The first step in locating ground is to _____________. 168 a. examine the main bus bars for signs of overheating b. eliminate the individual circuits one by one until the ground detecting system no longer indicates any grounds c. change over generators d. check each circuit with a megohmeter Ans. B To protect the rotor of a motor disassembled for 511. maintenance or overhaul, it should be _____________. a. suspended by wire slings in one corner of the shop b. wrapped it with heavy papers or lint free cloth c. support by flat wood blocks on the workbench d. return to the frame as soon as the bearing is removed Ans. B Which of the following material is a good 512. insulator ? a. glass b. steel c. aluminum d. copper Ans. A Which of the conditions listed below will indicate 513. the need to clean the insulation on the windings of an electric motor? a. higher than normal operating temperature 169 b. excessive vibration at normal speed c. sparking at the brushes d. high megger readings Ans. A If the energy input is significantly reduced to the 514. prime mover of one shipboard alternator operating in parallel with others, that alternator will ___. a. continue to operate at no load b. lose its load and overspeed c. begin to motorize and then trip out d. slow down and operate at reduced load Ans. C The failure of ball bearings used in electric motors 515. can result from ________. a. failure to clean the bearing before repacking b. failure to maintain proper alignment c. excessive grease in bearing thus eliminating room for expansion d. all of these choices Ans. D Which of the listed condition will occur if dirt and 516. grease are allowed to accumulate between the commutator segments of a motor? a. partial short circuit b. a dead short circuit c. misalignment of the motor shaft d. overspeeding of the motor Ans. A 170 A damp armature windings in an AC motor may 517. lead to _______________. a. reduced voltage b. reduced current c. Increased resistance d. overheating Ans. D A single-phase induction motor starts, reaches 518. 75% rated speed, slows down and accelerates again. The problem is most likely in the _____. a. starting winding b. running winding c. starting capacitor d. running centrifugal switch Ans. B On large generators, space heaters are used to 519. _______________. a. keep the machine at ambient temperature of the machinery space b. maintain motor parts above dew point to prevent condensation c. prevent condensation on the bearings d. prevent stack up of rotating parts Ans. B If a brush on a DC generator is only partially 520. seated, which of the following problems may occur? a. high current density developing at the contact surface b. continual overheating at the brush line 171 c. the brush will spark during the operation of the generator d. all of these choices Ans. D Most conducting materials such as copper, 521. aluminum, iron, nickel and tungsten ______. a. increase in resistance with increased temperature b. increase in resistance with decreased temperature c. decrease in resistance with increased temperature d. increase in conductance with increased temperature Ans. A Electric motor ball bearings designed to be filled 522. with grease should have the relief plug temporarily renewed while grease is being added. This plug should remain out until the machinery has been operated and warmed up to ensure that __________. 172 a. a path of expansion is provided for the grease b. all air pockets are vented from the grease c. dirt and grit are flushed from the bearing house d. the grease is properly distributed within the bearing Ans. A A large generator is provide with a space heater 523. to ________________. a. keep the machine at ambient temperature of the machinery space b. maintain rotor and stator winding temperature above dew point c. prevent condensation in the lube oil d. prevent electrolysis due to condensation in the bearings Ans. B If air gap readings from an electrical generating 524. machine have changed significantly from the last reading, you should check __________. a. the bearings b. insulation readings and machine cleanliness 173 c. prime movers thrust bearing d. the field coil bolts for proper tightness Ans. A Routine AC motor maintenance should include 525. periodic ____________. a. temperature readings at normal loads to detect abnormal temperature rise b. inspection of motor internals for loose rotor bars c. verifying the RPM is within normal range d. all of these choices Ans. A When removing ball or roller bearings from the 526. shaft of a motor, you should use a ___. a. rawhide hammer b. brass mallet c. wheel puller d. soft iron pry bar Ans. C A circuit that has one of two wires in contact with 527. the hull of a ship is called a_______. a. grounded circuit b. short circuit c. series circuit d. closed circuit 174 Ans. A Encrusted dirt accumulated inside a motor should 528. be removed with a _________. a. fiber scrapper b. painted welding rod c. hammer and chisel d. paint scraper Ans. A Silicone diodes designed for a specific reverse 529. breakdown voltage, become useful as an electronic power supply voltage regulator is called ________________. a. tunnel diodes b. hot-carrier diodes c. compensating diodes d. zener diodes Ans. D Which of the listed devices may be used as a 530. digital device? a. variable resistor b. diode c. strain gauge d. thermistor Ans. B Which of the listed condition is an advantage of a 531. PN diode over a vacuum diode? a. longer life b. no warm up time c. less delicate 175 d. all of these choices Ans. D 532. Heat sinks are frequently used with _______. a. power transistors b. vacuum tubes c. tunnel rectifier diodes d. all of these choices Ans. A 533. A semiconductor is a material with a ________. a. conductivity higher than a normal conductor b. conductivity higher than a normal insulator c. high conductivity at low temperature d. low conductivity at high temperature Ans. B Which of the listed conditions describes the effect 534. on intrinsic semiconductor operation as a result of a temperature increase? a. capacitive reactance will decrease b. conductivity will increase c. inductive reactance will decrease d. resistivity will increase Ans. B Brushless generators are designed to operate w/ 535. out the use of _____________. a. brushes b. slip rings 176 c. commutator d. all of these choices Ans. D On a diesel electric plant, raising the generators 536. field excitation will cause the DC propulsion motor to _____________. a. increase in speed b. decrease in speed c. affect the generator speed only d. affect the main motor speed Ans. A Electric propulsion coupling excitation is reduced 537. at slow speeds to_____________. a. increase speed control b. increase shaft torque c. prevent coupling from overheating d. prevent coupling from slippage Ans. C When choosing a battery for a particular 538. application, major consideration should be given to the battery’s _____________. 177 a. ampere hour capacity b. terminal polarity c. stability under changes d. ambient temperature rise Ans. A An electrical device w/c employs a stationary 539. armature and a rotating electromagnetic field is used aboard ship as a ___________. a. magnetic amplifier b. ship service alternator c. three-wire generator d. saturable reactor Ans. B A lead-acid battery is considered fully charged 540. _____________. a. when the electrolyte is gassing b. ammeter indicates positive reading c. terminal voltage reaches constant value d. specific gravity no longer increases 1 to 4 hours Ans. D Electrical circuits are protected against 541. overheating by means of a/an _______. a. circuit breaker b. amplifier c. diode 178 d. capacitor Ans. A Which of the following electrical properties will be 542. the same with respect to each component in series circuit? a. voltage b. current c. resistance d. inductance Ans. B Which of the following components are used to 543. convert AC to DC? a. armature and equalizer b. commutator and brushes c. rotor and interpoles d. field excitation Ans. B Line loses in a distribution circuit are kept to a 544. minimum by _____________. a. adding rubber insulation in the circuit b. using high current and low voltage c. increase boosters in the line d. using higher voltage and low current Ans. D To minimize magnetic field excitation between 545. electrical conductors in physical proximity, it is best to keep them _____________. a. parallel and as close as possible to each other 179 b. at right angles with each other c. parallel and far away from one another d. at right angles and as far away as practicable for one another Ans. D As insulation resistance reading is taken at 20 546. degrees Celsius and found to be 10 megohms. What would expect the resistance reading a. 2.5 ohms b. 10 ohms c. 15 ohms d. 20 ohms Given: Insulation Resistance Temp. = 20o Standard Insulation Temp. = 40oC Resistance RDG? Formula R40 = KT x RT Where: R40 = Corrected IR KT = Correction Factor RT = Insulation Resistance RDG for diff. temp. Ans. A The amount of current flow required for the 547. cathodic protection of a vessel is dependent upon the _____________. a. amount of bare steel surface b. speed of the ship through water c. temperature of the water d. all of these choices Ans. D When paralleling two AC generator, which of the 548. following actions should be the final step? a. adjusting the governor b. balancing the load c. closing the circuit breakers d. closing the equalizing switch 180 Ans. B Which type of AC single-phase motor will also 549. operate on DC ? a. split-phase b. series-wound c. shaded pole d. repulsion-start Ans. B The standard procedure for maintaining the 550. charge in a battery is to trickle charge _______. a. continuously b. at least once a week c. whenever the charge falls below 75% d. whenever the specific gravity falls below 1.2 Ans. A A lead acid battery may become hotter than 551. normal during a charge if the _______. a. battery has shorted cell b. charging voltage is low c. specific gravity is too high d. battery room door is secured Ans. A Before touching a small capacitor connected to 552. de-energize circuit, or even the one that is completely disconnected, one should _______________. a. tap it with screwdriver b. use a de-energise tag 181 c. use a puller d. short circuit the terminal Ans. D Kilowatt load is divided between two AC 553. generators operating in parallel by _______. a. adjusting the governor control b. varging the excitation voltage c. increase prime mover speed d. decrease prime mover speed Ans. A In a simple series circuit, the entire source voltage 554. will drop across _____________. a. the resistor next to the negative terminal b. a short circuit c. an open circuit d. resistor next to the terminal Ans. C Excessive heat in an operating motor controller 555. can result from _____________. a. a closed starter contact b. loose connection c. missing arc chute d. low motor starting torque 182 Ans. B 556. An ammeter should be used to measure _____. a. the voltage between two points in a circuit b. circuit continuity c. current flow in a circuit d. total or partial circuit resistance Ans. C What is the approximate voltage per cell produced 557. by the nickel-iron battery? a. 0.25 volts b. 1.35 volts c. 1.5 volts d. 6.0 volts Ans. B Which of the methods listed below is used to start 558. an AC generator turning? a. residual magnetism remaining in the field poles b. residual magnetism remaining in the field coils 183 c. residual magnetism remaining in the armature d. none of these choices Ans. D A handheld digital tachometer could give a bad 559. reading if _____________. a. aimed directly at the shaft b. partially aimed at the fluorescent light bulb c. the tape is too shiny d. positioned too close to the shaft Ans. B Under normal condition storage batteries used for 560. starting emergency diesel generator are maintained in a charged state by which of the following methods? a. trickle charging b. fast charging c. equalizing charge d. full charging Ans. A The number of cycles per second occurring in an 561. AC voltage is known as the ____. a. phase angle b. frequency c. wave form 184 d. half mode Ans. B When the electrolyte level of lead-acid storage 562. battery has decreased due to normal evaporation, the level should be re-established by adding _______? a. distilled water only b. sulfuric acid only c. a weak solution of distilled water and sulfuric acid d. a strong solution of distilled water and sulfuric acid Ans. A Which of the listed classes of electrical insulation 563. are suited for the highest operating temperature? a. class O-90 b. class A-105 c. class B-130 d. class H-180 Ans. D The armature cores of DC motors are constructed 564. with laminators to _________. a. eliminate hysteresis b. minimize brush sparking c. reduce eddy current loses d. compensate for armature reaction 185 Ans. C When paralleling two AC alternators using 565. synchronizing lamp only, both lamps will go dark when the alternators are __________. a. running at the same speed b. grounded c. of same polarity d. in phase Ans. D A lead-acid battery cell sustaining short circuit 566. _______________. a. will have unusually high voltage b. will be indicated by lime accumulation on the terminal posts c. have excessively high temperature while being charged d. cannot complete full charging Ans. C Which of the instrument listed below is used for 567. checking insulation? a. magnetometer b. megohmmeter c. dynamometer 186 d. ammeter Ans. B Equalization of the power factors of two 568. alternators operating in parallel is accomplished _____________. a. manually, by adjusting the governor control b. automatically, by automatic voltage regulators c. manually, adjusting the output of current transformer d. automatically, by the designed action of the governors Ans. B The field strength of a ship’s service DC generator 569. is adjusted by varying the ____. a. speed of the generator b. no. of field poles on the line c. power factor of the field d. resistance in the field Ans. D To parallel two generators, you should start the 570. prime mover _____________. a. close the circuit breaker, adjust the voltage then balance the loads 187 b. close the circuit breaker, adjust the bus voltage then balance the loads c. close the circuit breaker and the equalizer switch then balance the loads d. adjust the voltage, close the circuit breaker then balance the loads Ans. D A lead acid battery can deliver 20 amperes 571. continuously for 10 hours with an ampere-hour rating of _____________. a. 20 b. 40 c. 200 d. 400 Ans. C Which of the following statements, concerning the 572. general maintenance of a brushless generator is correct? a. paint should be applied to insulating surfaces on an annual basis b. alcohol should be used to remove dust and grime from the windings c. high pressure air should be used to blow out carbon dust d. accessible generator parts should be wiped with a clean dry rag on a periodic basis Ans. D 573. The inductance of a coil is measured in _____. a. ohms b. volts c. henries 188 d. amperes Ans. C 574. The resistance of a conductor varies ______. a. directly as its length and inversely as its cross sectional area b. inversely as its length and directly as its cross sectional area c. directly as its length and directly its cross sectional area d. inversely as its length and inversely as its cross sectional area Ans. A The Wheatstone bridge is a precision measuring 575. instrument utilizing the principle of changes in _____________. a. inductance b. capacitance c. resistance d. amperage Ans. C Which of the following should be the FIRST step 576. in removing a generator from parallel operation? a. trip the generator off the switchboard b. turn off the electrical equipment c. remove the load from the off-going generator 189 d. increase the cycle of the generator staying on the line Ans. C To limit the current flow through a DC voltmeter to 577. as low as possible, the moving cool circuit is provided with a/an __________. a. high series resistance b. high parallel resistance c. average voltage d. peak voltage only Ans. A Most AC voltmeters are calibrated to indicate 578. _____________. a. peak-to-peak voltage b. root mean square voltage c. average voltage d. peak voltage only Ans. B Which of the ff conditions indicates a short579. circuited capacitor when ducking condition with an ohmmeter? a. the capacitor shows changing but the final resistance reading is appreciably less than normal b. the reading is practically zero and remains 190 there c. the capacitor shows no changing action, but indicates a very high resistance d. the pointer moves quickly to the low resistance side of the scale, then slowly recedes towards infinity Ans. B Hand portable phase sequence indicators are 580. useful when _____________. a. preparing to parallel alternator b. connecting lighting branch circuits c. trouble-shooting DC motors d. correcting shore power lines to the ship Ans. D The capacity of storage battery is measured in 581. _____________. a. amp-hour capacity b. volts c. farads d. amps Ans. A You are paralleling two alternators. The 582. synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the "0" position. This indicates that the _____________. a. alternator voltage are 180 degrees apart 191 b. circuit breaker can be closed c. incoming alternator is running too slowly d. synchroscope is defective or broken Ans. B When mixing electrolyte for a lead-acid battery 583. _____________. a. stirring should always be avoided b. a lead container should always be used c. always pour the water into the acid d. always pour the acid into the water Ans. D Which of the listed forms of water should be 584. added to a lead-acid battery? a. saltwater b. brackish water c. distilled water d. light water Ans. C Which of the problems listed below will occur with 585. a lead-acid battery is allowed to remain in a discharged position for a long period of time? a. the battery may not be able to accept a full charge 192 b. the electrolyte will turn sour c. the corticosteroid sulfuric acid will attack the plates d. the separators will harden Ans. A When you check the specific gravity of the battery 586. electrolyte with a hydrometer, it should be kept in mind that _____________. a. the battery is fully charged when the indicator floats low in the electrolyte b. any water that has been previously added to the cells will dilute the solution and give false reading c. a hydrometer reading is inaccurate if taken immediately after water is added to the cell d. temperature has an effect on hydrometer readings Ans. C A reverse current relay will prevent AC generator 587. motorization by _____________. a. automatically redirecting the load b. automatically speeding up the prime mover c. tripping the panel board main switch 193 d. tripping the generator circuit breaker Ans. D One of the generator or motor bearings is 588. generally insulated from the end housing in order to prevent _____________. a. rapid brush wear b. current leakage from shaft c. excessive field winding heat d. circulation of shaft currents induced in the machine frame Ans. D An increase in the mount of current flow through 589. the armature of a shunt motor is the final result of a/an _____________. a. increase in the load on the motor b. decrease in the load on the motor c. increase in counter EMF d. decrease in armature torque Ans. A A motor enclosure which protects against falling 590. liquids is classified as _________. a. waterproof b. drop proof c. spray tight 194 d. moisture free Ans. B Insufficient brush pressure on a DC motor may 591. cause _____________. a. generator overload b. excess residual magnetism c. water vapor absorption d. sparking of the brushes Ans. D The type of motor control circuit that fails to pick 592. up when the coil voltage is applied to the contractor coil, the cause may be _____________. a. low voltage protection b. low voltage release c. overload lock-out d. reduced voltage starter Ans. A If magnetic controller contactor fails to pick up 593. when the coil voltage is applied to the contactor coil, the cause may be _________. a. overload b. misalignment of contacts 195 c. low spring pressure d. an open contactor coil Ans. D The use of four diodes, in a full-wave bridge 594. rectifier circuit, will _____________. a. provide unidirectional current on load b. allow high leakage current on load c. convert DC to AC d. all of these choices Ans. A Motor controllers are seldom troubled with 595. grounds because _____________. a. the auxiliary contact have high resistance connection b. the contractors and relays are mounted in a non-conducting panel c. the resistor banks are ground-proof d. separate switches are available Ans. B A constant out voltage from an AC generator is 596. maintained by the _____________. a. prime mover b. voltage regulator c. exciter generator 196 d. reverse power relay Ans. B 597. Power transformers are rated in _______. a. kilowatts b. ampere turns c. kilowatt-volts d. kilovolt-amperes Ans. D An insulation test is performed on an electrical 598. equipment. Besides resistance reading, what should be entered in the electrical log? a. maximum allowable temperature b. temperature of machine at the time the reading is taken c. the normal temperature rise of the machine d. none of these choices Ans. B A voltage relay with the addition of an air bleed, or 599. a dashpot to delay the action of its contacts, is often used for ___________. a. sequence control b. acceleration control c. low voltage release 197 d. all of these choices Ans. D Which of the solid AWG wire size has the smallest 600. physical cross-sectional area __. a. 12 b. 14 c. 16 d. 18 Ans. D An adjustable resistor, whose resistance can be 601. changed without opening the circuit in which it is connected is called a/an __________. a. bleeder resistor b. rheostat c. transistor d. bridge Ans. B The function of a stepdown transformer is to 602. reduce the load _____________. a. voltage and current b. voltage and increase line current c. current and increase line voltage 198 d. power Ans. B A loud buzzing noise in an AC controller is 603. probably caused by _____________. a. poor contact with the overload relay b. an incorrect sized heater c. a broken shading coil d. abnormal starting current Ans. C Increasing the load to the secondary windings of a 604. transformer will cause a/an ____. a. decrease in primary voltage b. increase in primary voltage c. decrease in primary current d. increase in primary current Ans. D What is the function of the voltage regulators used 605. with AC generators ? a. to cut out generators when they are no longer 199 b. to cut an additional generator automatically as required c. to divide the KW load between the two generators d. to divide reactive current between generators operating in parallel Ans. D The basic operation principle of a transformer is 606. attributed to _____________. a. electromagnetic induction b. variance of a conductor in a magnetic field c. mutual reaction d. thermal transmission Ans. A Which of the meters listed should be used after a 607. circuit has been electronically disconnected ? a. wattmeter b. frequency meter c. ammeter d. ohmmeter Ans. D The output voltage of a 440V, 60Hz AC generator 608. is controlled by the _________. a. load on the alternator b. load on the prime mover c. speed of the prime mover d. exciter output voltage 200 Ans. C When a transformer is used to step down voltage, 609. the low voltage winding is _____. a. part of core b. the primary coil c. the secondary coil d. not insulated Ans. C Magnetic chatter on “pumping" occurring in a 610. magnetic contactor can be caused by _____________. a. dirt or grease in contact surfaces b. mechanical interference in the contacts c. chattering contacts on the relay d. magnetic lockout of the relay Ans. C Relative to the secondary winding of a step-up 611. transformer, the primary winding will have _____________. a. more turns b. fewer turns c. half as many turns d. twice as many turns Ans. B To equalize the power factor of two alternators 612. operating in parallel, the _________. a. field excitation of both units is adjusted b. governor of both units are adjusted c. kilowatt load is evenly divided 201 d. phase sequence is altered Ans. A When trouble shooting motor controllers, a 613. shorted relay or contractor coil is often indicated by _____________. a. a resistance reading of infinity or an ohmmeter b. charred insulation and/or blown control fuse c. a reading of zero on a megger d. a higher than normal voltage reading Ans. B You can determine if a circuit breaker is tripped by 614. _____________. a. examining the position of the handle b. checking for the warm breaker c. looking for a burnt out link d. looking for the tripped breaker light Ans. A During maintenance of circuit breakers 615. _____________. a. always smooth roughened contact surfaces with a file b. never pass more than rated breaker current through the loaded element 202 c. inspect for wear and misalignment of main contacts d. assume heater elements installed are of correct size Ans. C Accidental grounds is a shipboard electrical 616. system must be repaired as soon as possible as they will _________. a. result in immediate power outages b. damage circuit breakers c. appear on the ground detection system d. damage insulation and may cause outages Ans. D Which of the following statement is TRUE 617. concerning transformer operation? a. the inductance in the primary side is the same as the secondary side b. voltage is the same of primary side and the secondary side c. current is the same of primary side and the secondary side d. power to the primary side is higher than the power in the secondary side Ans. D A lamp has a source voltage of 110 volts and a 618. current of 0.9 amps. What is the resistance of the lamp? a. 0.008 ohm b. 0.08 ohm c. 12.22 ohm 203 d. 122.22 ohm Ans. D A voltage regulator installed in a direct current 619. generator serves the purpose of ___. a. varying the shunt field resistance b. adjusting the cross current c. lowering the armature circuit resistance d. limiting the compensating field resistance Ans. A Electric motors intended for use outside the 620. engine room are frequently rated to run at a designed ambient temperature of 40 degrees centigrade. What is the equivalent temperature in degrees Fahrenheit? a. 54.2 degrees Fahrenheit b. 72 degrees Fahrenheit c. 104 degrees Fahrenheit d. 129.6 degrees Fahrenheit Ans. C A direct current passing through a wire wrapped 621. around a soft iron is a good example of a simple ___________. a. magnetic shield b. electromagnet c. transformer d. armature 204 Ans. B Which of the substances mentioned below can be 622. used to shield sensitive equipment from static magnetic fields? a. permeable iron b. glass c. varnished cloth0 d. bakelite Ans. A The timer element found in a reverse-power relay 623. obtains the operating torque via _________. a. line voltage b. the main bus c. electromagnets d. a separate battery source Ans. C Coast Guard Regulation 46 CFR require each 624. switchboard to have ____________. a. non-conductive deck covering at the front b. conductive deck covering at the front c. a nameplate for each circuit breaker d. all of these choices Ans. D Emergency lightings aboardship should be a/an 625. ______________. a. illuminated at all times while vessel is underway b. illuminated automatically and actuated upon failure of the main lighting system 205 c. portable battery operated and have sufficient capacity d. all of these choices Ans. B As per Coast Guard Regulations 46 CFR, 626. emergency generator set aboard ocean-going vessels must be capable of supplying emergency lightings for a minimum period of ______________. a. 18 hours b. 36 hours c. 24 hours d. 6 hours Ans. A As per Coast Guard Regulations 46 CFR, 627. emergency generator fuel tank full capacity must be capable of supplying the unit for a period of _____________. a. 6 hours b. 18 hours c. 24 hours d. 36 hours Ans. B As per Coast Guard Regulation 46 CFR, which of 628. the below listed items is the only permissible starting aid for the emergency diesel generator engine? a. ether b. lube oil heater c. jacket water heater 206 d. fuel oil heater Ans. C The source of emergency lighting and power loss 629. of normal ship's power on a cargo vessel should be obtained from the ______________. a. emergency generator supply to the emergency switchboard b. emergency generator supply to the main switchboard c. battery supply to the main switchboard d. turbogenerator supply to the emergency switchboard Ans. A An electrical device which employs a stationary 630. armature and a rotating magnetic field is used aboardship as a ___________. a. magnetic amplifier b. ship service generator c. DC generator d. saturable core reactor Ans. B According to USCG Regulations 46 CFR, how 631. often shall internal combustion engine driven emergency generators be operated under load? a. once a week for 2 hours b. once a month for 2 hours c. every six (6) months for 4 hours 207 d. once a week for 4 hours Ans. B Note; Ship below 500GRT The emergency switchboard 24v DC supply is 632. used to provide power to the ______. a. general alarm system b. gyrocompass power supply system c. smoke detection system d. all of these choices Ans. D 633. TV station operates at frequencies in the range of ________. A. 30Mhz to 300Mhz or 50Mhz (VHF) B. 1700Mhz C.2400Mhz D.5Mhz Ans. A 634. What will be the frequency of a three phase, six pole A/C generator operating at 1800 revolutions per minute? a. 60 Hz b. 90 Hz c. 120 Hz d. 180 Hz 208 PN Legend: f= f = frequency 120 P = Number of poles N = RPM 6 (1800) 120 = Constant f= 120 = 90 Hz Ans. B 635. TV stations are confined to broad cost in the frequencies above ______. a. 5.0 mega Hz b. 50.0 mega Hz c. 1,700 kilo Hz d. 2,400 kilo Hz Ans. B 636. What type of motor is NOT suitable for DC source? a. Squirrel cage b. Shunt c. Series d. Compound Ans. A 209 637. What is the approximate voltage per cell produced by the NICKEL-IRON (Edison) battery? a. 0.85 volts b. 1.35 volts c. 2.20 volts d. 6.05 volts Ans. B 638. In order to take a current reading with a CLAMP-ON-AMMETER, the instrument jaws_________. a. should remain open b. can not touch the adjacent conductor c. must be fully closed d. will act as a transformer primary Ans. C 639. When securing an AC generator, what procedure should you follow? a. reduce the load, trip the circuit breaker, stop the prime mover speed b. reduce the load, stop the prime mover speed, trip the circuit breaker c. trip the circuit breaker, reduce the load, stop the prime mover speed 210 Ans. A 640. The ability of a material to RETAIN SMALL AMOUNT OF MAGNETISM or MAGNETIC LINES OF FORCE when the magnetizing force is removed. a. retentivity b. magnetically saturated c. residual magnetism Ans. A 641. One advantage of AC generator over DC generator is that___ a. No sparking at the brushes b. No overheating Ans. A 642. Periodic testing of circuit breakers is necessary to assure that a correctly rated and properly installed unit _______. A. Can trip faster as it increases in age B. Will continue to provide the original degree of protection C.Does not exceed its interrupting capacity D.Be able to withstand at least 125% of applied voltage 211 Ans. B 643. What is the purpose of fuse place in series with a thermal trip type circuit breaker? A. Time-delay protection B. Short circuit protection C.Short duration surge protection D.Sustained overload protection Ans. B 644. The engine starting fuel setting/metering of the governor is usually set at _______. A. Dead slow ahead B. Slow ahead C.Half ahead D.Between slow and half ahead Ans. D 645. Some materials are neither good conductors nor good insulators since their electrical characteristic fall between those of conductors and insulators. These in between materials are known as _____. A. Semi-conductors B. Semi-metals C.Solid-state devices D.Semi-insulators Ans. A 212 646. An inspection which is in regular intervals is called a/an _______. A. Periodic inspection B. Preventive maintenance inspection C.Regular maintenance inspection D.Initial inspection Ans. A 647. Which of the following types of motors is often designed for use in correcting power factor? A. Polyphase B. Wound-rotor C. Induction D. Synchronous Ans. D 648. Failure in the mechanical governor spring will result in _______. A. Increase in engine speed B. Decrease in engine speed C. Governor to hunt D. Will not affect the engine Ans. B 649. Most electronic device/parts is constructed of __. A. Copper 213 B. Gold C.Silver D.Matter Ans. C 650. The air gap in an induction motor should be periodically checked with feeler gauge to prevent possible. A. Rotor contact with the stator/rotor clearance B. Loaded alternator is turning faster than the incoming machine C. Damaged to the motor bearings Ans. A 651. If a speed of an engine fitted with isosynchronous governor suddenly increases, after compensation is performed by the governor, the engine speed will _________. A. Remain the same B. Increase C. Decrease D. None of these Ans. A 214 652. Two base material used in semi-conductors are silicon and _______. A. salt B. gemanium C. diode D. transistor Ans. B 653. What is the simplest way of voltage regulation? A. Zener diode B. Transistor C. Resistor D. Capacitor Ans. A 654. The most outstanding characteristics of a Zener diode is that, even current changes widely, it is constant in ________. A. Load B. Voltage C. Frequency D. Power Ans. B 215 655. Most part of engine system is composed of two alarms. Which of the following system consisting a single alarm only? A. Low lube oil pressure B. Low lube oil sump tank C. High jacket cooling water temperature D. High main bearing temperature Ans. A Note; Only Lube oil pressure alarm consist a single alarm, because this automatically shutdown the engine. While sump tank level consist of low level and low-low level alarm, jacket water and main bearing temperature consist of high temp. and high-high temp (slowdown) alarms. 656. Diesel engine automated control system may utilize sensing devices of dual function, with sensing ranges providing both alarm & engine shutdown capability. Which of the key points listed below would require only an alarm sensor? A. Engine overspeed B. Lube oil sump low level C. Lube oil pressure low D. Main bearing temperature high Ans. B Note; Sump tank level consist only of alarms such as low and low-low level alarm. While engine overspeed and lube oil press. alarm consist of an alarm and shutdown. Then Main bearing temperature consist of an alarm and slowdown. 216 657. Which of the listed logic gates is considered to be a BASIC building block used in logic diagrams? I – NAND II – OR III – NOR A. I only B. II only C. III only D. All of these Ans. B 658. Which device/machine designated to operate without the use of commutator & brushes? A. Brushless AC generator B. Brushless DC generator C. Slip ring AC generator D. Slip ring DC generator Ans. A 659. Routine maintenance of lead acid batteries should include ______. A. Keeping the terminals clean B. Coating cable connections with petroleum jelly C. Maintaining a trickle charge D. All of these Ans. D 660. The transmit & receive elements of a soundpowered telephone handset are ________. 217 A. Identical & can be used for either function B. Of similar construction but different enough to be used only of its own function C. Of very different construction & must be used only for its own function D. Constructed so that each can fit only in its own recess Ans. A 661. A continuous fluctuation of the governorcontrolled speed is known as _______. A. hunting B. droop C. sensitivity D. stability Ans. A 662. When working on a high voltage circuit, you should always have another person present with you. This person should have a good working knowledge of _________. I – The circuit being worked on & the location of all switches & circuit breakers controlling it II – First aid techniques for treating electrical shock III – Cardiopulmonary resuscitation (CPR) A. I only B. II only C. III only D. I, II & III Ans. D 218 663. Which of the following statements about a threephase wye connection is correct? A. The line current is 1.73 times the phase current B. The phase current is 1.73 times the line current C. The line voltage is 1.73 times the phase voltage D. The phase voltage is 1.73 times the line voltage Ans. C 664. The need for insulation cleaning may be determined by _____. A. B. C. D. Visual inspection for dirt accumulation High megger readings Low operating temperature The time period since the last cleaning Ans. A 665. Periodical testing by a shoreside support using a special camera which can detect potentially dangerous loose or corroded bus bar & controller connections is termed _______. A. B. C. D. Heat sensitive thermography Visual pyrotronics Corrosion electrolysis Electric vibroanalysis Ans. A 219 666. You have installed a Zener diode in parallel with the load. While measuring the voltage across the Zener it is found that it does not change as the current through load increases which means ____. A. B. C. D. is working as it should is shorted is open does not regulate as it should Ans. A 667. The basic control action of an magnetic amplifier depends upon ____. A. B. C. D. Variations in the load capacitance Changes in inductance Type of core material Construction of the core Ans. B 668. When a ship service generator equipped with centrifugal type hydraulic governor load increases, what action will occur in the governor internal mechanism? A. B. C. D. Weigh will move inward Lifting will have inward Pilot valve bushing is lowered Oil is pumped into the cylinder Ans. C 669. If only one brush on a commutator is sparking excessively, you should look for _______. 220 A. B. C. D. A high commutator bar Copper imbedded in the brush A loose commutator bar Flux in the commutator zone Ans. B 670. The rated temperature rise of an electric motor is the ________. A. Average temperature at any given latitude B. Normal temperature rise above the standard ambient temperature at rated load C. Average temperature at rated load D. Permissible difference in the ambient temperature of the motor due to existing weather condition Ans. B 671. The heat required to changed a substance from a solid to a liquid while at its freezing temperature, is known as the latent heat of ________. A. B. C. D. fusion vaporization condensation sublimation Ans. A 672. What is placed in a circuit for current to flow in one direction only? A. Transformer B. Capacitor 221 C. Transistor D. Diode Ans. D 673. Charge bodies attract or repel each other is in what law? A. B. C. D. Magnetism law Ohm’s law Electromagnet law Kirchoff’s law Ans. A 674. What law that describes how the materials attract & repel when ENERGIZED? A. B. C. D. Magnetism law Ohms law Electromagnet law Kirchoff’s law Ans. C 675. When a transistor has very and almost equal forward & reverse resistance between its emitter & base leads, the device is ________. A. B. C. D. good grounded bad shorted Ans. D 676. If atom loses an electron and has an overall (+) positive charge, it becomes ______. 222 A. B. C. D. Light atoms + ion Fast moving atoms Slow moving atoms Ans. B 677. Which of the combustion parameters listed is used in a diesel engine, but NOT related to the injection system? A. B. C. D. Atomization Metering Effective stroke Penetration Ans. D 678. Which of the listed governor operating characteristics is considered to be isochronous? A. B. C. D. Zero speed droop Positive speed droop Negative speed droop Varying speed droop Ans. A The full torque electric brake on an electric cargo 679. winch functions to ___. a. act as a backup brake in case the mechanical brake should fail b. automatically hold the load as seen as 223 current to the machine is shut off c. automatically reduce lowering speed d. automatically reduce hoisting speed Ans. B Moisture damage due to consideration inside the 680. cargo winch master switches can be reduced by _____________. a. installing light bulb in the pedestal stand b. sealing the switchbox c. venting the switchbox regularly d. using strip heaters inside the switch box Ans. D In the event of a power failure during cargo 681. loading operations, the movement of an electric powered cargo will be stopped by ______. a. manual override switch b. spring set brake c. hand-operated brake d. weight of the boom load Ans. B The greatest enemy of an idle electrical 682. equipment such as a pump room fan motor is the _____________. a. loss of magnetism b. moisture in the insulation c. insulation varnish flaking d. dirt accumulation on the windings Ans. B 224 Which of the following represents the best method 683. of cleaning dust from electrical circuits in order to limit damage to electronic components? a. wipe off with soft cotton rag b. use high velocity compressed air c. use vacuum cleaner d. use chemical solvent Ans. C In an induction motor, rotor currents are circulated 684. in the rotor by ____. a. slip ring and brushes b. armature and brushes c. inductive reaction of rotating stator field d. external variable resistor Ans. C A circuit breaker and a fuse have basic similarity 685. in that they both ____. a. can be reset to energize the circuit b. should open the circuit when overload develops c. will burn out when overload develops d. all of these choices Ans. B Electrical leads and insulation on a motor should 686. be painted with ___. a. heat resisting acrylic b. heat resistant aluminum c. insulating varnish 225 d. insulating white lead Ans. C A degree of control over speed of slip ring 687. induction motor can be obtained by _______. a. adjusting governor linkage b. changing the number of coils on the motor c. inserting assistance to the stator d. inserting resistance to the rotor Ans. D A circuit breaker differs from a fuse because a 688. circuit breaker can ___. a. melt and be replaced b. enclosed tube has insulating material c. gives no visual condition d. trips to break the circuit and my be reset Ans. D The main purpose of an auxiliary windings as a 689. split-phase, single-phase motor is to____. a. limit the starting voltage b. increase starting current c. start the motor d. keep the motor running Ans. C The state of charge of a lead acid storage battery 690. is best indicated by _____________. a. testing individual cell voltages 226 b. ampere hour capacity c. specific gravity of electrolyte d. total cell voltage Ans. C A low voltage source is being used for testing 691. armature coils. A short circuit will be indicated by a _____________. a. high voltage reading b. zero or low voltage reading c. fluctuating voltmeter reading d. steady voltmeter reading Ans. B Which of the listed procedures should be carried 692. out to prevent moisture damage to idled electrical apparatus? a. inert the space b. strap silica gel c. place heat lamps d. cover the equipment with canvass Ans. C Electric heaters are used in motor controllers to 693. _____________. a. prevent movable contacts from freezing b. keep components warm c. prevent condensation of moisture d. maintain good resistance of circuit Ans. C A fuse that blows often should be replaced only 694. with fuse of _______. 227 a. recommended current and rating b. higher current and rating c. lower current and rating d. none of these choices Ans. A Which of the listed precautions should be 695. observed before spraying liquid solvent on the insulation of an electric motor? a. slow the motor down to low speed b. disconnect the motor from the power source c. secure all ventilation in the area d. pre-heat the insulation Ans. B On a tanker vessel with electrically driven 696. capstan, the motor should be megged periodically to test _____________. a. insulation resistance b. eddy currents c. capacitance d. armature reactance Ans. A A reverse power current relay prevents AC 697. generator motorization automatically by ___. a. transferring the load b. speed up the prime mover c. secure the exciter generator d. tripping the circuit breaker Ans. D 228 Which of the following devices will prevent an AC 698. generator from becoming motorized? a. overcurrent relay b. relay trip c. governor control d. reverse current/power relay Ans. D 699. A grounded switch or cable will be indicated by a megohmeter of _____________. a. infinity b. zero c. unsteady reading in high range d. unsteady reading in low range Ans. B Batteries used for diesel engine starting should 700. _____________. a. be located in a locker on the weather deck b. be located as close as possible to the engine c. have capacity to start the engine up to 50 times d. none of these choices Ans. B Before testing insulation with a megohmeter, the 701. windings of large machines should be grounded for 15 minutes because ___________. a. static charge in the machine may give false 229 reading b. insulation may get damaged c. insulation may be wet d. machine may run automatically Ans. A Battery charging rooms should be well-ventilated 702. because the charging process _____. a. produces highly poisonous hydrogen b. produces highly combustible oxygen c. liberates explosive gases d. liberates corrosive gases Ans. C When a megger is used to test insulation, the 703. gradual rise of the pointer reading as a result of continued cranking, is caused by ___________. a. good resistance b. leakage in the winding c. inductive resistance in windings d. dielectric-absorption effect of the insulation Ans. D Most 3-phase induction motors for driving engine 704. room auxiliaries are started by ______. a. resistor starters b. across-the-line starters c. impedance starters d. reactor starters Ans. B 230 First aid treatment for battery acid or alkali burns, 705. especially in the eyes, includes ______. a. flushing with large amounts of fresh water b. wiping the affected area with clean dry cloth c. using talcum powder to counter itching d. all of these choices Ans. A A hydrometer is used to measure 706. _____________. a. specific gravity of battery electrolyte b. water pressure on deck line c. amount of distilled water evaporator produced d. power developed by sea water service pump Ans. A Discharge switches are often located on hand707. driven meggers. The purpose of these switches is to discharge capacitive charges stored in the _______________. a. megger hand generator b. movement coils c. tested equipment while conducting test d. tested equipment after conducting test Ans. D A megohmmeter can be used to test for 708. _____________. 231 a. an open field b. synchronous speed c. frequency d. high voltage prsence Ans. A You are attempting to parallel two AC generator 709. and the synchroscope pointer is revolving slowly in the fast direction. You should ________. a. use the governor switch to adjust incoming voltage so it is equal to the voltage b. use the governor switch to increase the speed of the prime mover c. close the circuit breaker when the synchroscope pointer approaches “0” position d. close the circuit breaker when the synchroscope pointer approaches “180” position Ans. C A fuse will blow for all the listed reasons except 710. _____________. a. excessive vibration b. extremely hot surroundings c. loose fuse clips d. low contact resistance within the fuse Ans. D Moisture absorbed in the windings or condensed 711. on the surface of electrical machinery insulation _____________. 232 a. is good for the machinery as additional insulation b. lowers insulation value and may create grounds c. enhance insulation value of the machine d. reduce the amount of current to be fed to the machine Ans. B In which of the situation listed will a megohmmeter 712. give the most accurate reading ? a. while the machine is in operation b. while the machine is about to stop operation c. immediately after the machine has stopped d. 15 minutes after the machine has been isolated and grounded Ans. D When using a multimeter for resistance 713. measurements, it should be calibrated by clipping the loose ends of the leads together and ____. a. setting the instrument pointer at zero ohms b. adjusting the line voltage to calibrate the instrument c. plugging each end of one test lead into the plus and minus terminals d. using special purpose resistance measuring instruments Ans. A Which of the following insulation will deteriorate 714. first as a result of heat 233 generated in the conductor it surrounds ? a. rubber b. varnished cloth c. silicon d. asbestos Ans. A A multimeter can be used to measure 715. _____________. a. resistance b. voltage c. current d. all of these choices Ans. D Which of the following problems will most likely 716. occur if the starting winding of a split-phase induction motor failed to cut-out once the motor was in continuous operation? a. the motor will overspeed b. the motor will run at a reduced speed c. the motor will stop d. the winding will burn out Ans. D When insulation failure produces a low resistance 717. current path between two conductors, the resulting condition is known as _____________. a. an open circuit b. a short circuit c. a ground 234 d. a surge Ans. B When disassembling motor for maintenance or 718. overhaul _________. a. punch mark frame and end bells for proper assembly b. wrap bearings in lint free cloth if they are to be reversed c. tag and store small parts in a box d. all of these choices Ans. D 719. Fuses are usually rated in _____________. a. watts b. amps only c. volts only d. amps and volts Ans. D When used for taking resistance measurements, 720. voltage-ohmmeter is normally paired by _____________. a. a hand cranked generator b. internal storage batteries c. the current in the circuit being tested d. a step-down transformer Ans. B When an AC or DC motor fails to start, the FIRST 721. step in troubleshooting should be to check the _____________. a. motor windings for obvious opens 235 b. motor controller leads for continuity c. fuse or circuit breaker d. motor controller leads to ground Ans. C A current-carrying conductor making electrical 722. contact with a wiring conduit will be indicated by a _____________. a. high switchboard wattmeter reading b. totally dark switchboard ground detecting light c. low switchboard wattmeter reading d. all of these choices Ans. B To remove an alternator operating in parallel with 723. mother unit from the main electrical bus, you must FIRST _____________. a. adjust the power factor on both units b. set the desired voltage on the outgoing alternator c. open the circuit breaker on the outgoing alternator d. remove the load from the outgoing alternator Ans. D When testing for blown fuses in a three-phase 724. supply circuit to a motor, you should first _____________. a. apply the megger across the tops of the line fuses b. apply the megger across the bottom of the line fuses 236 c. apply the voltage faster across the bottom of the line fuses d. de-energize the circuit and then use a continuity tester Ans. D In a three-phase electrical system, three ground 725. detecting lamps are provided. If all three lamps REMAIN at half brilliance when the ground detecting switch is operated _____________. a. there is a slight ground on all three phases b. the switch must be replaced c. there are no grounds present d. the light bulbs are of improper voltage Ans. C Electrical failures in motors are caused by the 726. breakdown of insulation, which maybe caused by _____________. a. penetration of moisture b. accumulation of dirt c. overheating d. all of these choices Ans. D In order to safely carry out repairs to a generator 727. circuit breaker, it must be isolated from the bus. This is accomplished by opening the ________. a. reverse power relay b. bus disconnect link c. generator bus fuse connection d. power directional relay 237 Ans. B If the voltage supplied to the lightning circuit is 110 728. volts. How much current is used by a 100 watt light bulb ? a. 0.08 amps b. 0.91 amps c. 1.10 amps d. 90.9 amps Ans. B According to USCG regulation (CFR 46) which of 729. the ff systems must be arranged so as to be energized by emergency power supply in case of power failure? a. at least one light is steering gear room b. each power operated watertight door system c. each changing panel for temporary emergency batteries d. all of these choices Ans. D Diesel generator # 1 & 2 are operating in parallel 730. at near full load capacity. Diesel generator # 1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions properly and trips generator # 1 off the board. Which of the following should you do FIRST? a. start the standby generator b. ascertain cause of low lube oil pressure 238 c. strip the board of non-vital loads d. secure alarm, reset all tripped relays and restart generator # 1 Ans. C The source of emergency lightning and power at 731. loss of normal-ship’s power on a cargo vessel should be obtained from the _____________. a. emergency switchboard b. main switchboard c. emergency batteries d. emergency power from main switchboard Ans. A International regulations states that continuous 732. trickle charge supplied from the ship’s required service power system, is for batteries supplying power to the __________. a. emergency diesel starting system b. emergency power system for radar c. emergency power system for steering gear d. emergency power system for lifeboat radios Ans. A According to USCG Regulation 46CFR, the the 733. talking and calling circuits of a sound powered telephone system must be __________. a. intrinsically safe b. independent of each other c. independently grounded d. connect to a common ground 239 Ans. B Which of the listed safety features should be 734. provided in a small room or locker where batteries are stored? a. install a CO2 system b. install an exhaust system fan c. an exhaust duct to be made 3 feet above the deck d. exhaust duct is to be provided from the top of the locker to open air Ans. D You should not allow salt water to enter a lead 735. acid battery or come in contact with sulfuric acid because _____________. a. resulting gas is extremely flammable b. the resulting gas is a respiratory irritant that can be fatal c. the primary constituent, sodium, reacts lethally with lead peroxide d. continuing salt water with lead acid creates a harmful gas Ans. B Which of the ff should be done when a 10 amp 736. blown fuse is replaced ? a. short out the fuse b. replace blown fuse with less than 10 amp rating c. replace blown fuse with exactly 10 amp rating d. none of these choices 240 Ans. C International Regulations requires that an 737. indicating light at the propulsion control station will activate if overloading or overheating occurs in a ____________. a. forced draft fan b. steering gear motor c. fuel pump motor d. condensate pump motor Ans. B International regulations requires that a remote 738. stop/start button for engine room bilge pump shall be located at _____________. a. main deck / upper deck b. emergency generator room c. engine control room d. cargo control room Ans. A International regulations requires a continuous 739. trickle charge is to be applied from the ship’s service power system for batteries supplying power to the ___________. a. emergency power for bridge and engine control rooms b. portable radios fro the lifeboat c. emergency power and lightings d. all of the above Ans. C 241 A multimeter may be damaged by taking a 740. _____________. a. voltage reading while in the resistance mode b. current reading while in voltmeter mode c. resistance reading while in the ammeter mode d. resistance reading while in the voltmeter mode Ans. A When replacing fuses, always make sure 741. _____________. a. to stand on a rubber mat and use rubber gloves b. to use insulated pliers or screwdrivers c. the fuse clips are straight, tight and holding the new fuses well d. to increase the fuse rating by 1-% to guard against “nuisance” blowing Ans. C If all the grounds lamps burn with equal brilliance, 742. whether the test button is depressed and released, which of the listed conditions is indicated? a. no ground exist b. all three phases are grounded c. the test switch is faulty d. the current transformers are shorted out Ans. A 743. The ground indicating light on the main 242 switchboard is indicating a ground. The last procedure for locating the grounded circuit is to ____________. a. trace the circuit’s paths while looking for burned spots b. open the circuit breakers on the distribution panel one by one until the lights no longer indicate a ground c. check circuits for continuity d. none of these choices Ans. B An ohmmeter can be used to test for 744. _____________. a. an open field coil b. a shorted field pole c. reverse polarity d. low voltage supply Ans. A Electrical machinery insulation will breakdown 745. more rapidly due to ________. a. low loading of motor and generators b. frequent megger testing c. high temperature and vibration d. high operating frequencies Ans. C Low horsepower, poly-phase conduction motors 746. can be started with full voltage by means of _____________. a. compensator starters b. auto transformer starters 243 c. across the line starters d. primary resistor starters Ans. C Which of the following conditions will occur if the 747. solenoid coil burns out on a cargo winch with an electric brake ? a. the brake will be set by spring force b. the motor will overspeed and burn out c. the load suspended from the cargo boom will fall d. none of these choices Ans. A External shunts are sometimes used with 748. ammeters to _____________. a. increase meter sensitivity b. prevent shunts with larger resistance to be utilized c. prevent damage to the meter movement from heat generated by the shunt d. enable the construction of a compact meter with a virtually unlimited range Ans. C Which of the following statements is correct in the 749. maintenance of contacts in relays ? a. they should dressed with wire wheel b. they should be dressed w/ fine cut file if surface is uneven c. if burns are noticed, at should be removed w/ sandpaper d. should be held together with every paper 244 driven between contacts Ans. B A signal derived from a controlled function and 750. returned to the initiating point is called a/an _____________. a. monitoring signal b. inverse signal c. reverse signal d. feedback signal Ans. D A device which prints out a permanent record of 751. the plant operating conditions is known as the _____________. a. analog logger b. bell book c. alarm logger d. data logger Ans. D The speed of squirrel cage induction motor is 752. determined by the _______. a. diameter of the stator b. no. of stator poles c. rotor winding resistance d. stator winding resistance Ans. B Under which of the listed conditions can the 753. engine room retake the throttle control from the bridge ? a. anytime it deemed necessary 245 b. only w/ master’s permission c. after 10 min. delay to the command d. only when the throttle is at stop Ans. A A generator has been exposed to water and is 754. being checked for its safe operation. Therefore it is necessary to ________. a. check for shorted coils b. take moisture reading c. test insulation reading d. ground the commutator and run it for half an hour Ans. C A squirrel-cage motor is designed to have 755. _____________. a. low starting voltage b. low starting current c. high starting voltage d. low starting resistance Ans. B In a DC series circuit, all the conductors have the 756. same _____________. a. power consumption b. voltage drop across c. current passing thru them d. resistance passing thru them Ans. C 757. Which of the AWG wire sizes listed below would 246 have the smallest diameter ? a. 000 b. 0 c. 12 d. 250 Ans. C When using a megger to test insulation, good 758. insulation will be indicated by ______. a. slight kick of the needle downscale b. downward dip followed by gradual climb to the true resistance value c. initial dip of pointer d. gradual rise in the pointer Ans. B A reverse-current relay will prevent DC generator 759. motorization by _______. a. automatically redirecting the load b. automatically speeding up the prime mover c. tripping the panel board main switch d. tripping the generator circuit breaker Ans. D If many turns of an alternating current coil 760. contractor become short circuited, the coil ___. a. temperature will drop b. will probably burn out completely c. will continue to operate d. will operate on reduced current 247 Ans. B How is a wattmeter electrically connected in a 761. circuit ? a. in series b. in parallel c. in series-parallel d. inductively Ans. C Which of the listed conditions would indicate the 762. need for cleaning electrical insulation ? a. low ambient temperature b. low operating temperature c. high dielectric strength d. low megger readings Ans. D A multimeter maybe damaged by taking a 763. _____________. a. voltage reading while in the ammeter mode b. current reading while in the voltmeter mode c. resistance reading in the ammeter mode d. resistance reading in the voltmeter mode Ans. A Multiple grounds have developed and were initially 764. indicated by the ground detecting system as one ground. The first step in locating ground is to _____________. a. examine the main bus bars for signs of 248 overheating b. eliminate the individual circuits one by one until te ground detecting system no longer indicates any grounds c. change over generators d. check each circuit with a megohmeter Ans. B To protect the rotor of a motor disassembled for 765. maintenance or overhaul, it should be _____________. a. suspended by wire slings in one corner of the shop b. wrapped it with heavy papers or lint free cloth c. support by flat wood blocks on the workbench d. return to the frame as soon as the bearing is removed Ans. B Which of the following material is a good 766. insulator ? a. glass b. steel c. aluminum d. copper Ans. A Which of the conditions listed below will indicate 767. the need to clean the insulation on the windings of an electric motor? a. higher than normal operating temperature b. excessive vibration at normal speed 249 c. sparking at the brushes d. high megger readings Ans. A If all the ground detection lamps burn with equal 768. brilliance, whether the test button is depressed or released, then ________. a. no ground exist b. all phases are grounded c. all lamps show a ground d. all of these choices Ans. A If the energy input is significantly reduced to the 769. prime mover of one shipboard alternator operating in parallel with others, that alternator will ___. a. continue to operate at no load b. lose its load and overspeed c. begin to motorize and then trip out d. slow down and operate at reduced load Ans. C The failure of ball bearings used in electric motors 770. can result from ________. a. failure to clean the bearing before repacking b. failure to maintain proper alignment c. excessive grease in bearing thus eliminating room for expansion d. all of these choices Ans. D 250 Which of the listed condition will occur if dirt and 771. grease are allowed to accumulate between the commutator segments of a motor? a. partial short circuit b. a dead short circuit c. misalignment of the motor shaft d. overspeeding of the motor Ans. A A damp armature windings in an AC motor may 772. lead to _______________. a. reduced voltage b. reduced current c. Increased resistance d. overheating Ans. D A single-phase induction motor starts, reaches 773. 75% rated speed, slows down and accelerates again. The problem is most likely in the _____. a. starting winding b. running winding c. starting capacitor d. running centrifugal switch Ans. B On large generators, space heaters are used to 774. _______________. a. keep the machine at ambient temperature of the machinery space b. maintain motor parts above dew point to 251 prevent condensation c. prevent condensation on the bearings d. prevent stack up of rotating parts Ans. B If a brush on a DC generator is only partially 775. seated, which of the following problems may occur? a. high current density developing at the contact surface b. continual overheating at the brush line c. the brush will spark during the operation of the generator d. all of these choices Ans. D Most conducting materials such as copper, 776. aluminum, iron, nickel and tungsten ______. a. increase in resistance with increased temperature b. increase in resistance with decreased temperature c. decrease in resistance with increased temperature d. increase in conductance with increased temperature Ans. A Electric motor ball bearings designed to be filled 777. with grease should have the relief plug temporarily renewed while grease is being added. This plug should remain out until the machinery has 252 been operated and warmed up to ensure that __________. a. a path of expansion is provided for the grease b. all air pockets are vented from the grease c. dirt and grit are flushed from the bearing house d. the grease is properly distributed within the bearing Ans. A A large generator is provide with a space heater to 778. ________________. a. keep the machine at ambient temperature of the machinery space b. maintain rotor and stator winding temperature above dew point c. prevent condensation in the lube oil d. prevent electrolysis due to condensation in the bearings Ans. B If air gap readings from an electrical generating 779. machine have changed significantly from the last reading, you should check __________. a. the bearings b. insulation readings and machine cleanliness c. prime movers thrust bearing d. the field coil bolts for proper tightness Ans. A Routine AC motor maintenance should include 780. periodic ____________. 253 a. temperature readings at normal loads to detect abnormal temperature rise b. inspection of motor internals for loose rotor bars c. verifying the RPM is within normal range d. all of these choices Ans. A When removing ball or roller bearings from the 781. shaft of a motor, you should use a ___. a. rawhide hammer b. brass mallet c. wheel puller d. soft iron pry bar Ans. C A circuit that has one of two wires in contact with 782. the hull of a ship is called a_______. a. grounded circuit b. short circuit c. series circuit d. closed circuit Ans. A Encrusted dirt accumulated inside a motor should 783. be removed with a _________. a. fiber scrapper b. painted welding rod c. hammer and chisel d. paint scraper Ans. A 784. Silicone diodes designed for a specific reverse 254 breakdown voltage, become useful as an electronic power supply voltage regulator is called ________________. a. tunnel diodes b. hot-carrier diodes c. compensating diodes d. zener diodes Ans. D Which of the listed devices may be used as a 785. digital device? a. variable resistor b. diode c. strain gauge d. thermistor Ans. B Which of the listed condition is an advantage of a 786. PN diode over a vacuum diode? a. longer life b. no warm up time c. less delicate d. all of these choices Ans. D Heat sinks are frequently used with 787. _____________. a. power transistors b. vacuum tubes c. tunnel rectifier diodes d. all of these choices Ans. A 255 A semiconductor is a material with a 788. _______________. a. conductivity higher than a normal conductor b. conductivity higher than a normal insulator c. high conductivity at low temperature d. low conductivity at high temperature Ans. B Which of the listed conditions describes the effect 789. on intrinsic semiconductor operation as a result of a temperature increase? a. capacitive reactance will decrease b. conductivity will increase c. inductive reactance will decrease d. resistivity will increase Ans. B Brushless generators are designed to operate w/ 790. out the use of _____________. a. brushes b. slip rings c. commutator d. all of these choices Ans. D On a diesel electric plant, raising the generators 791. field excitation will cause the DC propulsion motor to _____________. a. increase in speed b. decrease in speed c. affect the generator speed only d. affect the main motor speed 256 Ans. A Electric propulsion coupling excitation is reduced 792. at slow speeds to_____________. a. increase speed control b. increase shaft torque c. prevent coupling from overheating d. prevent coupling from slippage Ans. C 793. When choosing a battery for a particular application, major consideration should be given to the battery’s _____________. a. ampere hour capacity b. terminal polarity c. stability under changes d. ambient temperature rise Ans. A An electrical device w/c employs a stationary 794. armature and a rotating electromagnetic field is used aboard ship as a ___________. a. magnetic amplifier b. ship service alternator c. three-wire generator d. saturable reactor Ans. B A lead-acid battery is considered fully charged 795. _____________. a. when the electrolyte is gassing b. ammeter indicates positive reading 257 c. terminal voltage reaches constant value d. specific gravity no longer increases 1 to 4 hours Ans. D Electrical circuits are protected against 796. overheating by means of a/an _______. a. circuit breaker b. amplifier c. diode d. capacitor Ans. A Which of the following electrical properties will be 797. the same with respect to each component in series circuit? a. voltage b. current c. resistance d. inductance Ans. B Which of the following components are used to 798. convert AC to DC? a. armature and equalizer b. commutator and brushes c. rotor and interpoles d. field excitation Ans. B Line loses in a distribution circuit are kept to a 799. minimum by _____________. a. adding rubber insulation in the circuit 258 b. using high current and low voltage c. increase boosters in the line d. using higher voltage and low current Ans. D To minimize magnetic field excitation between 800. electrical conductors in physical proximity, it is best to keep them _____________. a. parallel and as close as possible to each other b. at right angles with each other c. parallel and far away from one another d. at right angles and as far away as practicable for one another Ans. D As insulation resistance reading is taken at 20 801. degrees Celsius and found to be 10 megohms. What would expect the resistance reading a. 2.5 ohms b. 10 ohms c. 15 ohms d. 20 ohms Ans. A The amount of current flow required for the 802. cathodic protection of a vessel is dependent upon the _____________. a. amount of bare steel surface b. speed of the ship through water c. temperature of the water d. all of these choices 259 Ans. D When paralleling two AC generator, which of the 803. following actions should be the final step? a. adjusting the governor b. balancing the load c. closing the circuit breakers d. closing the equalizing switch Ans. B Which type of AC single-phase motor will also 804. operate on DC ? a. split-phase b. series-wound c. shaded pole d. repulsion-start Ans. B The standard procedure for maintaining the 805. charge in a battery is to trickle charge _____________. a. continuously b. at least once a week c. whenever the charge falls below 75% d. whenever the specific gravity falls below 1.2 Ans. A A lead acid battery may become hotter than 806. normal during a charge if the _______. a. battery has shorted cell b. charging voltage is low c. specific gravity is too high 260 d. battery room door is secured Ans. A Before touching a small capacitor connected to 807. de-energize circuit, or even the one that is completely disconnected, one should _______________. a. tap it with screwdriver b. use a de-energise tag c. use a puller d. short circuit the terminal Ans. D Kilowatt load is divided between two AC 808. generators operating in parallel by _______. a. adjusting the governor control b. varging the excitation voltage c. increase prime mover speed d. decrease prime mover speed Ans. A In a simple series circuit, the entire source voltage 809. will drop across _____________. a. the resistor next to the negative terminal b. a short circuit c. an open circuit d. resistor next to the terminal Ans. C Excessive heat in an operating motor controller 810. can result from _____________. a. a closed starter contact b. loose connection 261 c. missing arc chute d. low motor starting torque Ans. B An ammeter should be used to measure 811. _____________. a. the voltage between two points in a circuit b. circuit continuity c. current flow in a circuit d. total or partial circuit resistance Ans. C What is the approximate voltage per cell produced 812. by the nickel-iron battery? a. 0.25 volts b. 1.35 volts c. 1.5 volts d. 6.0 volts Ans. B Which of the methods listed below is used to start 813. an AC generator turning? a. residual magnetism remaining in the field poles b. residual magnetism remaining in the field coils c. residual magnetism remaining in the armature d. none of these choices Ans. D A handheld digital tachometer could give a bad 814. reading if _____________. 262 a. aimed directly at the shaft b. partially aimed at the fluorescent light bulb c. the tape is too shiny d. positioned too close to the shaft Ans. B Under normal condition storage batteries used for 815. starting emergency diesel generator are maintained in a charged state by which of the following methods? a. trickle charging b. fast charging c. equalizing charge d. full charging Ans. A The number of cycles per second occurring in an 816. AC voltage is known as the ____. a. phase angle b. frequency c. wave form d. half mode Ans. B When the electrolyte level of lead-acid storage 817. battery has decreased due to normal evaporation, the level should be reestablished by adding a. distilled water only b. sulfuric acid only c. a weak solution of distilled water and sulfuric acid d. a strong solution of distilled water and sulfuric acid 263 Ans. A Which of the listed classes of electrical insulation 818. are suited for the highest operating temperature? a. class O b. class A c. class B d. class H Ans. D The armature cores of DC motors are constructed 819. with laminators to _________. a. eliminate hysteresis b. minimize brush sparking c. reduce eddy current loses d. compensate for armature reaction Ans. C When paralleling two AC alternators using 820. synchronizing lamp only, both lamps will go dark when the alternators are __________. a. running at the same speed b. grounded c. of same polarity d. in phase Ans. D A lead-acid battery cell sustaining short circuit 821. _______________. a. will have unusually high voltage b. will be indicated by lime accumulation on the 264 terminal posts c. have excessively high temperature while being charged d. cannot complete full charging Ans. C Which of the instrument listed below is used for 822. checking insulation? a. magnetometer b. megohmmeter c. dynamometer d. ammeter Ans. B Equalization of the power factors of two 823. alternators operating in parallel is accomplished _____________. a. manually, by adjusting the governor control b. automatically, by automatic voltage regulators c. manually, adjusting the output of current transformer d. automatically, by the designed action of the governors Ans. B The field strength of a ship’s service DC generator 824. is adjusted by varying the ____. a. speed of the generator b. no. of field poles on the line c. power factor of the field d. resistance in the field Ans. D 265 To parallel two generators, you should start the 825. prime mover _____________. a. close the circuit breaker, adjust the voltage then balance the loads b. close the circuit breaker, adjust the bus voltage then balance the loads c. close the circuit breaker and the equalizer switch then balance the loads d. adjust the voltage, close the circuit breaker then balance the loads Ans. D A lead acid battery can deliver 20 amperes 826. continuously for 10 hours with an ampere-hour rating of _____________. a. 20 b. 40 c. 200 d. 400 Ans. C Which of the following statements, concerning the 827. general maintenance of a brushless generator is correct? a. paint should be applied to insulating surfaces on an annual basis b. alcohol should be used to remove dust and grime from the windings c. high pressure air should be used to blow out carbon dust d. accessible generator parts should be wiped with a clean dry rag on a periodic basis 266 Ans. D The inductance of a coil is measured in 828. _____________. a. ohms b. volts c. henries d. amperes Ans. C The resistance of a conductor varies 829. _____________. a. directly as its length and inversely as its cross sectional area b. inversely as its length and directly as its cross sectional area c. directly as its length and directly its cross sectional area d. inversely as its length and inversely as its cross sectional area Ans. A The Wheatstone bridge is a precision measuring 830. instrument utilizing the principle of changes in _____________. a. inductance b. capacitance c. resistance d. amperage Ans. C Which of the following should be the FIRST step 831. in removing a generator from parallel operation? 267 a. trip the generator off the switchboard b. turn off the electrical equipment c. remove the load from the off-going generator d. increase the cycle of the generator staying on the line Ans. C To limit the current flow through a DC voltmeter to 832. as low as possible, the moving cool circuit is provided with a/an __________. a. high series resistance b. high parallel resistance c. average voltage d. peak voltage only Ans. A Most AC voltmeters are calibrated to indicate 833. _____________. a. peak-to-peak voltage b. root mean square voltage c. average voltage d. peak voltage only Ans. B Which of the ff conditions indicates a short834. circuited capacitor when ducking condition with an ohmmeter? a. the capacitor shows changing but the final resistance reading is appreciably less than normal b. the reading is practically zero and remains there 268 c. the capacitor shows no changing action, but indicates a very high resistance d. the pointer moves quickly to the low resistance side of the scale, then slowly recedes towards infinity Ans. B Hand portable phase sequence indicators are 835. useful when _____________. a. preparing to parallel alternator b. connecting lighting branch circuits c. trouble-shooting DC motors d. correcting shore power lines to the ship Ans. D The capacity of storage battery is measured in 836. _____________. a. amp-hour capacity b. volts c. farads d. amps Ans. A You are paralleling two alternators. The 837. synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the "0" position. This indicates that the _____________. a. alternator voltage are 180 degrees apart b. circuit breaker can be closed c. incoming alternator is running too slowly d. synchroscope is defective or broken Ans. B 269 When mixing electrolyte for a lead-acid battery 838. _____________. a. stirring should always be avoided b. a lead container should always be used c. always pour the water into the acid d. always pour the acid into the water Ans. D Which of the listed forms of water should be 839. added to a lead-acid battery? a. saltwater b. brackish water c. distilled water d. light water Ans. C Which of the problems listed below will occur with 840. a lead-acid battery is allowed to remain in a discharged position for a long period of time? a. the battery may not be able to accept a full charge b. the electrolyte will turn sour c. the corticosteroid sulfuric acid will attack the plates d. the separators will harden Ans. A When you check the specific gravity of the battery 841. electrolyte with a hydrometer, it should be kept in mind that _____________. a. the battery is fully charged when the indicator 270 floats low in the electrolyte b. any water that has been previously added to the cells will dilute the solution and give false reading c. a hydrometer reading is inaccurate if taken immediately after water is added to the cell d. temperature has an effect on hydrometer readings Ans. C A reverse current relay will prevent AC generator 842. motorization by _____________. a. automatically redirecting the load b. automatically speeding up the prime mover c. tripping the panel board main switch d. tripping the generator circuit breaker Ans. D One of the generator or motor bearings is 843. generally insulated from the end housing in order to prevent _____________. a. rapid brush wear b. current leakage from shaft c. excessive field winding heat d. circulation of shaft currents induced in the machine frame Ans. D An increase in the mount of current flow through 844. the armature of a shunt motor is the final result of a/an _____________. a. increase in the load on the motor b. decrease in the load on the motor 271 c. increase in counter EMF d. decrease in armature torque Ans. A A motor enclosure which protects against falling 845. liquids is classified as _________. a. waterproof b. drip proof c. spray tight d. moisture free Ans. B Insufficient brush pressure on a DC motor may 846. cause _____________. a. generator overload b. excess residual magnetism c. water vapor absorption d. sparking of the brushes Ans. D The type of motor control circuit that fails to pick 847. up when the coil voltage is applied to the contractor coil, the cause may be _____________. a. low voltage protection b. low voltage release c. overload lock-out d. reduced voltage starter Ans. A If magnetic controller contactor fails to pick up 848. when the coil voltage is applied to the contactor coil, the cause may be 272 _________. a. overload b. misalignment of contacts c. low spring pressure d. an open contactor coil Ans. D The use of four diodes, in a full-wave bridge 849. rectifier circuit, will _____________. a. provide unidirectional current on load b. allow high leakage current on load c. convert DC to AC d. all of these choices Ans. A Motor controllers are seldom troubled with 850. grounds because _____________. a. the auxiliary contact have high resistance connection b. the contractors and relays are mounted in a non-conducting panel c. the resistor banks are ground-proof d. separate switches are available Ans. B A constant out voltage from an AC generator is 851. maintained by the _____________. a. prime mover b. voltage regulator c. exciter generator d. reverse power relay Ans. B 273 Power transformers are rated in 852. _____________. a. kilowatts b. ampere turns c. kilowatt-volts d. kilovolt-amperes Ans. D An insulation test is performed on an electrical 853. equipment. Besides resistance reading, what should be entered in the electrical log? a. maximum allowable temperature b. temperature of machine at the time the reading is taken c. the normal temperature rise of the machine d. none of these choices Ans. B A voltage relay with the addition of an air bleed, or 854. a dashpot to delay the action of its contacts, is often used for ___________. a. sequence control b. acceleration control c. low voltage release d. all of these choices Ans. D Which of the solid AWG wire size has the smallest 855. physical cross-sectional area __. a. 12 b. 14 c. 16 274 d. 18 Ans. D An adjustable resistor, whose resistance can be 856. changed without opening the circuit in which it is connected is called a/an __________. a. bleeder resistor b. rheostat c. transistor d. bridge Ans. B The function of a stepdown transformer is to 857. reduce the load _____________. a. voltage and current b. voltage and increase line current c. current and increase line voltage d. power Ans. B A loud buzzing noise in an AC controller is 858. probably caused by _____________. a. poor contact with the overload relay b. an incorrect sized heater c. a broken shading coil d. abnormal starting current Ans. C Increasing the load to the secondary windings of a 859. transformer will cause a/an ____. a. decrease in primary voltage b. increase in primary voltage 275 c. decrease in primary current d. increase in primary current Ans. D What is the function of the voltage regulators used 860. with AC generators ? a. to cut out generators when they are no longer b. to cut an additional generator automatically as required c. to divide the KW load between the two generators d. to divide reactive current between generators operating in parallel Ans. D The basic operation principle of a transformer is 861. attributed to _____________. a. electromagnetic induction b. variance of a conductor in a magnetic field c. mutual reaction d. thermal transmission Ans. A Which of the meters listed should be used after a 862. circuit has been electronically disconnected ? a. wattmeter b. frequency meter c. ammeter d. ohmmeter Ans. D 276 The output voltage of a 440V, 60Hz AC generator 863. is controlled by the _________. a. load on the alternator b. load on the prime mover c. speed of the prime mover d. exciter output voltage Ans. C When a transformer is used to step down voltage, 864. the low voltage winding is _____. a. part of core b. the primary coil c. the secondary coil d. not insulated Ans. C The cycle per second developed by an alternator 865. aboard your vessel is determined by _____________. a. The speed of the prime mover b. The resistance applied to the field rheostat c. The output of voltage regulator d. The output of excitation Ans. A Magnetic chatter on “pumping" occurring in a 866. magnetic contactor can be caused by _____________. a. dirt or grease in contact surfaces b. mechanical interference in the contacts c. chattering contacts on the relay d. magnetic lockout of the relay 277 Ans. C Relative to the secondary winding of a step-up 867. transformer, the primary winding will have _____________. a. more turns b. fewer turns c. half as many turns d. twice as many turns Ans. B To equalize the power factor of two alternators 868. operating in parallel, the _________. a. field excitation of both units is adjusted b. governor of both units are adjusted c. kilowatt load is evenly divided d. phase sequence is altered Ans. A When trouble shooting motor controllers, a 869. shorted relay or contractor coil is often indicated by _____________. a. a resistance reading of infinity or an ohmmeter b. charred insulation and/or blown control fuse c. a reading of zero on a megger d. a higher than normal voltage reading Ans. B You can determine if a circuit breaker is tripped by 870. _____________. a. examining the position of the handle b. checking for the warm breaker 278 c. looking for a burnt out link d. looking for the tripped breaker light Ans. A During maintenance of circuit breakers 871. _____________. a. always smooth roughened contact surfaces with a file b. never pass more than rated breaker current through the loaded element c. inspect for wear and misalignment of main contacts d. assume heater elements installed are of correct size Ans. C Accidental grounds is a shipboard electrical 872. system must be repaired as soon as possible as they will _________. a. result in immediate power outages b. damage circuit breakers c. appear on the ground detection system d. damage insulation and may cause outages Ans. D Which of the following statement is TRUE 873. concerning transformer operation? a. the inductance in the primary side is the same as the secondary side b. voltage is the same of primary side and the secondary side c. current is the same of primary side and the secondary side d. power to the primary side is higher than the 279 power in the secondary side Ans. D A lamp has a source voltage of 110 volts and a 874. current of 0.9 amps. What is the resistance of the lamp? a. 0.008 ohm b. 0.08 ohm c. 12.22 ohm d. 122.22 ohm Ans. D A voltage regulator installed in a direct current 875. generator serves the purpose of ___. a. varying the shunt field resistance b. adjusting the cross current c. lowering the armature circuit resistance d. limiting the compensating field resistance Ans. A Electric motors intended for use outside the 876. engine room are frequently rated to run at a designed ambient temperature of 40 degrees centigrade. What is the equivalent temperature in degrees fahrenheit? a. 54.2 degrees Fahrenheit b. 72 degrees Fahrenheit c. 104 degrees Fahrenheit d. 129.6 degrees Fahrenheit Ans. C A direct current passing through a wire wrapped 877. around a soft iron is a good 280 example of a simple ___________. a. magnetic shield b. electromagnet c. transformer d. armature Ans. B Which of the substances mentioned below can be 878. used to shield sensitive equipment from static magnetic fields? a. permeable iron b. glass c. varnished cloth0 d. bakelite Ans. A The timer element found in a reverse-power relay 879. obtains the operating torque via _____________. a. line voltage b. the main bus c. electromagnets d. a separate battery source Ans. C Coast Guard Regulation 46 CFR require each 880. switchboard to have ____________. a. non-conductive deck covering at the front b. non conductive deck covering at the rear c. a nameplate for each circuit breaker d. all of these choices Ans. D 281 Emergency lightings aboardship should be a/an 881. ______________. a. illuminated at all times while vessel is underway b. illuminated automatically and actuated upon failure of the main lighting system c. portable battery operated and have sufficient capacity d. all of these choices Ans. B As per Coast Guard Regulations 46 CFR, 882. emergency generator set aboard ocean-going vessels must be capable of supplying emergency lightings for a minimum period of ______________. a. 18 hours b. 36 hours c. 24 hours d. 6 hours Ans. A As per Coast Guard Regulations 46 CFR, 883. emergency generator fuel tank full capacity must be capable of supplying the unit for a period of _____________. a. 6 hours b. 18 hours c. 24 hours d. 36 hours Ans. B 884. As per Coast Guard Regulation 46 CFR, which of 282 the below listed items is the only permissible starting aid for the emergency diesel generator engine? a. ether b. lube oil heater c. jacket water heater d. fuel oil heater Ans. C The source of emergency lighting and power loss 885. of normal ship's power on a cargo vessel should be obtained from the ______________. a. emergency generator supply to the emergency switchboard b. emergency generator supply to the main switchboard c. battery supply to the main switchboard d. turbogenerator supply to the emergency switchboard Ans. A An electrical device which employs a stationary 886. armature and a rotating magnetic field is used aboardship as a ___________. a. magnetic amplifier b. ship service generator c. DC generator d. saturable core reactor Ans. B According to USCG Regulations 46 CFR, how 887. often shall internal combustion 283 engine driven emergency generators be operated under load? a. once a week for 2 hours b. once a month for 2 hours c. every six (6) months for 4 hours d. once a week for 4 hours Ans. B The emergency switchboard 24v DC supply is 888. used to provide power to the ______. a. general alarm system b. gyrocompass power supply system c. smoke detection system d. all of these choices Ans. D 284
