問題一覧
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51. What cause carbon deposits on the boiler burner throat ring?
•A dirty atomizer sprayer plate
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52. In a water-tube boiler, how is water level confirmed?
•Gauge glass
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53. What may happen if bubbles are present in a refrigeration system?
•Bubbles may carry moisture that may lead to corrosion.
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54. In the refrigeration system, the refrigerant absorbs the latent heat of vaporization in the ?
•evaporator
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55. Why is the heating capacity of the fuel oil heater reduced when there is a build up of carbonization in the heater surfaces ?
•Because thermal conductivity of solidified contaminant is poor
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56. Scavenging fire occur if the engine piston rings are ?
Leaking
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57. Sub-cooling is the method of reducing the temperature of the liquid refrigerant below its ?.
•condensing temperature
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58. How can we quickly reduce high water level in a steaming boiler?
•By the used of surface blow valve
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59. Humidity is the measure of the ?
•water vapor content
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60. Which turbocharger component increases air density and helps improve engine operating efficiency?
•After cooler
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61. The correct radial clearances between the rotor and the casing in a propulsion turbine are maintained by the turbine
•journal bearings
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62. Excess refrigerant in a refrigeration system is normally removed from the
•charging connection of the system.
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63. How is power transfered from the main engine located deep inside the hull of a vessel to the propeller at the aft?
• Via intermediate and propeller shaft
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64. Which one of the following devices use to control the admission of steam to the steam cylinder of a reciprocating pump ?
•Pilot valve and operating rod
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65. Cylinder inlet valve failure in a low pressure air compressor can be caused by ?
•sticking valves due to carbon buildup on the seats
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66. When should be a boiler water sample be taken for testing?
•Before the boiler has been blown down or chemicals added
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67. What is the possible cause why a lube oil pump fails to build up discharge pressure?
•suction valve is closed
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68. What is the heat exchanger used to heat the boiler feed water by means of waste gas as it passes from the boiler to the stack?
•Economizer
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69. The most common problem encountered by turbo-chargers in a two-stroke engine is ?
•surging
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70. The amount of supplied fuel oil on the boiler atomizer depends on the ?
•Fuel pressure
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71. If the existing vapour pressure is subtracted from the indicated pressure at the pump suction, the remainder is the ?
•apparent net positive suction head
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72. When the hydraulic control lever for a deck winch is placed in the neutral or off position, the spring set brake on the fluid motor drive shaft is
•engaged by spring action and only released by hydraulic pressure
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74. Oil mist detector is an instrument used to detect an oil mist formation in the engine crankcase , what cause oil formation ?
•Overheating of oil
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73. What is the purpose of the boiler drum air cock?
•permit escape of air when steam is forming in the drum after lighting off
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75. oil mist detector is an instrument used to detect an oil mist formation in the engine crankcase, what cause oil formation
• overheating of oil
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76. In a large, low-speed diesel engine the clearance between the piston crown and cylinder
•insert shims between the crankpin bearing box and the connecting rod foot
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77. Increasing the valve clearance of a diesel engine intake valve will cause the valve to open ?
•later and have greater lift
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78. Condensers located in the various stages of the flash evaporator are cooled by ?
•seawater
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79. What would be the result if the fuel used for boiler burners has sediments?
•Clogged atomizer tips
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80. An air compressor can be unloaded at start up by?
• relieving the intercooler pressure to the atmosphere.
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81. When operating under constant load, the superheated steam temperature may rise above normal it
•feed water temperature is too low
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82. An engineer on duty inspecting an unmanned engine room at night should be aware of which of the following precautions ?
•Switch on the dead man alarm upon entering the control room
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83. You observedan efficiency drop caused by compressor fouling of the gasturbine, what is the most effective counter measure to carry out?
•Off-line washing
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84. In a fuel oil burner having a standard mechanical atomizer, the fuel and air are mixed as the fuel leaves the ?
•orifice
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85. The difference between the setpoint and the measured parameter in an automatic flow controller is called:
•Error
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86. Why diesel engine lubricating oil need more purification compare with the lubricating oil in a gas turbine?
•Gas turbine lubricant does not come into contact with the combustion process
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87. The pressure developed in the high pressure cylinder of a reciprocating air compressor, in order to assure an output near the end of its compression stroke, is ?
•above the line discharge pressure
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88. Feedwater supplied to a flash type distilling plant will flash to vapor in the first-stage due to ?
•flash chamber pressure being lower than the saturation pressure corresponding to the feedwater temperature
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89. Every automated machinery plant must have an engineers assistance alarm. Power for this alarm should be taken from the
•general alarm power supply
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90. If an air compressor is used to supply air primarily to the combustion control system and other pneumatic controllers, the entire system is known as the ?
•control air system
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91. If the exhaust oil is returned directly to the pump suction, what type of hydraulic circuit is the system?
•closed loop
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92. Explain what is the use of Stern tube ?
•support and seal the propeller shaft
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93. The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speed. In maintaining this relationship, the camshaft drive causes the camshaft to rotate at ?
•crankshaft speed in a two-stroke cycle diesel engine
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94. A centrifugal pump may fail to deliver water when first started if the
•pump is not primed
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95. Boiler safety valves are set not to go above maximum operating pressure of higher than ?
•10%
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96. Which of the following is used as moisture arrester and dryer in the refrigeration system?
•Silica gel
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97. Fuel oil enters the main engine cylinder through?
•fuel oil injector
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98. Gland sealing steam is used during steam turbine operation to prevent the loss of
•vacuum
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99. The operation of a thermostatic steam trap depends upon the ?
•change in the amount of vapor produced within an enclosed chamber
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100. Which combination of the main shaft segments listed below that are located furthest from the main engine are connected by the inboard stern tube shaft coupling?
•Line shaft and stern tube shaft