Q717 - General Subjects, USCG prep certification 2026

Progress: 24% (23/94)

Learning progress ?

1. For the various sizes of tubing and wall thickness used in a hydraulic system, the inside diameter can be determined if it is remembered that the inside diameter equals the outside diameter less __________.Not learned 2. The letters 'NC' in '1/4-20 NC' indicates the bolt is __________.Not learned 3. To measure the circumference of a piece of pipe, you should use a __________.Not learned 4. Which of the instruments listed is used to measure the gauge of a piece of sheet metal?Not learned 5. Charring or glazing of the inner circumference of the packing rings in a centrifugal pump is caused by __________.Not learned 6. Which of the following statements is true regarding mechanical seals?Not learned 7. Concerning sentinel valves, what statement is true?Not learned 8. The function of seal cages, or lantern rings installed in the centrifugal pump stuffing boxes, is to __________.Not learned 9. Air leakage between the shaft and stuffing box packing in a centrifugal pump is prevented by __________.Not learned 10. One disadvantage of using a mechanical shaft seal instead of mechanical packing is that __________.Not learned 11. One of the consequences in continuing to operate a centrifugal bilge pump with the discharge valve closed, is that the _______.Not learned 12. If a centrifugal pump were continually operated with the discharge valve closed, the __________.Not learned 13. Why does a centrifugal bilge pump require priming?Not learned 14. Liquid is kept from leaking out at the shaft ends of a helical gear pump by __________.Not learned 15. In order to distribute the side pressures over a wide area of the cylinder walls and liners, which of the listed types of pistons are used in modern low-pressure air compressors?Not learned 16. Aftercoolers are used with air compressors to __________.Not learned 17. The general purpose of a heat exchanger is to __________.Not learned 18. With regard to the number of passes through the tubes of shell-and-tube heat exchangers, what statement is true?Not learned 19. What is meant by the term emergency bilge suction?Not learned 20. What is an engine room bilge oily-water separator designed to do?Not learned 21. What type of fuel oil as part of an oily-water mixture is most likely to have a density approaching that of water?Not learned 22. If an oily-water separator uses an inclined plate pack to facilitate separation, what statement concerning the plate pack is true?Not learned 23. Which of the following desalination plants will always require a sterilizer when providing water to a potable water system?Not learned 24. Which of the following statements concerning the arrangements of a potable water system is true?Not learned 25. What is the primary purpose of the lead-lag arrangement of the two potable water pumps supporting a typical potable water system?Not learned 26. Hot water heaters used in potable water systems may have multiple heat sources, such as an electric heating element and a jacket water heated tube bundle. What is the primary purpose of such an arrangement?Not learned 27. What operating condition (or conditions) would necessitate shifting from a high sea suction to a low sea suction for a machinery space sea water cooling system?Not learned 28. What provision is made for sea chests for removal of ice from within the sea chest of a machinery space sea water cooling system during operation in icy waters?Not learned 29. A reservoir, as used in hydraulic systems aboard ship, is used to store hydraulic oil. Another function is to __________.Not learned 30. The determining factor for the strength of a flexible rubber hydraulic hose is the __________.Not learned 31. A flare-type tubing connector is used in the hydraulic hatch cover system and has developed a slight leak. To stop the leak, you should __________.Not learned 32. The component used in a hydraulic system to store potential energy in the form of hydraulic fluid under pressure, is the __________.Not learned 33. The output volume of a positive fixed displacement pump can be changed only by __________.Not learned 34. Both the direction of flow and fluid flow rate of a variable displacement radial piston pump are determined by the relative positions of the __________.Not learned 35. To convert a vane type hydraulic pump to a hydraulic motor, which of the following would have to be done?Not learned 36. With an increase in temperature, the volume of hydraulic fluid __________.Not learned 37. Energy losses occurring in a hydraulic system are ultimately absorbed by the __________.Not learned 38. What is one benefit of maintenance of proper air circulation in an air-conditioned cargo space?Not learned 39. A reheater in an air conditioning system performs what function?Not learned 40. What type of HVAC system is characterized by poor air distribution and ventilation and low system heat loads?Not learned 41. What type of HVAC system is characterized by having control dampers in locations other than the outside air supply, outside air exhaust, and recirculation damper applications?Not learned 42. For safe storage, the maximum allowable temperature to which refrigerant bottles should be exposed is what temperature?Not learned 43. Which of the fluids listed is suitable and commonly used as a secondary refrigerant?Not learned 44. The amount of HCFC-123 in a storage cylinder is measured by what means?Not learned 45. What is the physical state and pressure condition of refrigerant as it leaves a receiver in a typical refrigeration system?Not learned 46. What is the pressure and condition of the refrigerant entering the receiver of a refrigeration system?Not learned 47. Why can CFC or HCFC refrigerants leaking into a confined space or in limited surroundings cause suffocation?Not learned 48. The gas that exists in the stratosphere forming a protective shield that helps to protect the environment from the harmful effects of ultraviolet radiation is called what?Not learned 49. A device used to hold open the refrigeration compressor suction valve during starting to reduce the compression load is called what?Not learned 50. The carbon seal ring of a refrigeration compressor crankshaft mechanical seal is held in position against the stationary ring face by using what device?Not learned 51. In general, the thermal bulb for a thermal expansion valve used in a reciprocating air conditioning system is usually charged with what substance?Not learned 52. In a refrigeration system, the pressure within the power element of a thermostatic expansion valve depends directly upon what factor?Not learned 53. In a refrigeration system, the bulb for the thermal expansion valve is always located where?Not learned 54. What is the purpose of running a refrigeration compressor in short intermittent spurts or throttling the suction isolation valve when starting the system after a prolonged shutdown?Not learned 55. When opening or closing compressor service and line isolation valves on a typical refrigeration system that is fitted with packed valves, what must you do?Not learned 56. Personnel servicing refrigeration systems that exposes them to commonly used refrigerants should wear what type of personal protective equipment?Not learned 57. Before charging a refrigeration unit, unless quick disconnect fittings are used, the refrigerant charging hoses should be prepared in what way?Not learned 58. Concerning the charging of refrigerant into a vapor compression refrigerating system, which of the following is true?Not learned 59. What must be done, at a minimum, before a system can legally be opened up for repairs while adhering to the prohibition against the venting of halogenated fluorocarbon refrigerants to the atmosphere?Not learned 60. What is the correct color-coding of refrigerant recovery cylinders regardless of the refrigerant contained within?Not learned 61. In a refrigeration system, the push-pull technique can be used for the recovery of the refrigerant in what state?Not learned 62. Which of the following fixed temperature heat-actuated fire detectors is the most prone to false alarms?Not learned 63. Probably the most useful troubleshooting tools used in a predictive maintenance management program for shipboard machinery are vibration meters, analyzers, and monitors. What is the term that represents the rate of change of the velocity as a result of a part vibrating during its periodic or oscillatory motion?Not learned 64. What is meant by a critical speed for rotating machinery?Not learned 65. Concerning governor speed droop, what statement is true?Not learned 66. Which of the following speed control devices is used strictly as a safety device to prevent prime mover damage and acts by shutting down the prime mover?Not learned 67. What type of temperature transmitter would be most suitable for measuring running gear bearing temperatures in a diesel engine in that it requires no contact with the bearing?Not learned 68. What type of temperature transmitter would be most suitable for measuring diesel engine exhaust and boiler stack temperatures and generates its own electromotive force?Not learned 69. In which lubrication application is a detergent type oil most likely to be used?Not learned 70. What is the operating principle of detergent type lubricating oil that provides the oil with its unique properties?Not learned 71. With respect to lubricating oils, what statement is true concerning viscosity and viscosity index?Not learned 72. The multiplier prefix "giga" (G) such as used in "gigabytes" represents what multiplication factor?Not learned 73. Contact with any energized electrical system conductor is potentially hazardous and precautions should be taken to prevent exposure. With all other factors considered equal (such as voltage, conducting path through the body and the duration of contact), contact with an energized electrical system conductor of which system type would produce the most damaging effect?Not learned 74. Which of the following devices would be forbidden to use as a primary means of electrical isolation?Not learned 75. Which of the following voltage testers would be associated with high quality, be safe to use, and minimize the electric shock hazard?Not learned 76. Which of the substances listed can be used to shield sensitive equipment from static magnetic fields?Not learned 77. Three 12-volt, lead-acid, batteries connected in series will develop how many volts?Not learned 78. According to 46 CFR Subchapter J, what is true concerning the installation of batteries used for diesel engine starting?Not learned 79. How will the value of the output frequency change if the load is removed from a turbogenerator having a governor speed droop setting of 3%?Not learned 80. Which of the methods listed below is used to provide the rotational torque to cause an AC generator to turn?Not learned 81. Which of the illustrated motors has an open motor enclosureNot learned 82. Of the following, what shipboard system is MOST likely to use the synchronous transmission system featuring a transmitter and receiver?Not learned 83. What is the functional name of an electrical device which prevents simultaneous energization of loads thereby preventing damage or injury?Not learned 84. Which of the following statements represents the main difference between an electromagnetic relay and an electromagnetic contactor as used in motor control and power circuits?Not learned 85. To facilitate communication between the wheelhouse and the steering gear room in a steering emergency where no external source of power is required, what means of two-way communication would be provided?Not learned 86. What does the symbol in figure "1" shown in the illustration representNot learned 87. A common-emitter circuit has an input voltage of 0.1 volt, an output voltage of 2.0 volts, an input current of 0.5 milliamps, and an output current of 10 milliamps. What is the power gain?Not learned 88. Which of the listed temperature sensors consists of finely coiled wire, such as platinum, where the resistance varies directly with temperature?Not learned 89. What is used to protect a direct sensing steam pressure gauge from damage from contact with steam?Not learned 90. A bearing temperature monitoring system such as that used for measuring selected propulsion plant bearings uses what technology?Not learned 91. Which of the following rotational shaft speed sensors produces a digital signal?Not learned 92. Which of the following liquid level sensors would be most suitable for measuring the liquid level in a pressure vessel, such as a water-tube boiler steam drum?Not learned 93. In a closed-loop process control system, what term is used to describe the action of measuring the difference between the actual result and the desired result and using that difference to drive the actual result toward the desired result?Not learned 94. In accordance with 33 CFR Subchapter O (Pollution), which type of Marine Sanitation Device (MSD) is used solely for the storage of sewage and flush water at ambient air pressure and temperature?Not learned 95. A common type of molded case circuit breaker has both thermal and magnetic trip elements. If a branch circuit breaker has only thermal or magnetic trip elements (but not both), it is common to use multiple series-connected protective devices to provide both short-circuit and overload protection. If a motor branch circuit is protected with both a thermal trip-type circuit breaker and fuses, what is the protective purpose of the fuses used in this arrangement?Not learned 96. The component labeled "CR1" in the circuit shown in the illustration serves what functional purposeNot learned 97. In which of the following branch circuits types would time lag fuses (or dual-element fuses) be MOST likely used?Not learned 98. Which of the following motors has a frame configuration for solid base mounting onlyNot learned 99. What is the functional purpose of a generic electromagnetic relay?Not learned 100. What is the functional purpose of the Zener diode "CR1" as shown in section "D" of the regulated DC power supplyNot learned 101. From the information given in the illustration, which of the following statements is correctNot learned 102. From the information given in the illustration, what would be the maximum output amperage available from the emergency generator if it operated with a power factor of 0Not learned 103. What is the name for the device shown in figure "A" of the illustrationNot learned 104. What is the name of the semiconductor device with the essential characteristic that it decreases in resistance with an increase in temperature?Not learned 105. Which pair of safety disconnect switches shown in the illustration represents the exterior and interior views of a double-throw switchNot learned 106. After prior isolation and lock-out/tag-out procedures are performed, which electrical device requires discharging any stored electrical energy before any work may safely begin?Not learned 107. As shown in the illustration, the wet cell storage batteries are connected in what configurationNot learned 108. A silicon-controlled rectifier (SCR) is a solid-state device used for what functional purpose?Not learned 109. Which of the wave shapes shown in the illustration is termed a sinusoidal waveNot learned 110. According to the illustration, which of the following conditions would most likely cause Pump "A" to short cycleNot learned 111. The best tool to use to measure the number of threads per inch on a bolt is a __________.Not learned 112. A 'centerline' depicted in a drawing or blueprint is represented by which of the figures shown in the illustrationNot learned 113. The components indicated as "7" and "8" as shown in the illustration, are known as the __________Not learned 114. Through which of the components shown in the illustration is flash gas formation a normal occurrenceNot learned 115. Concerning the proper installation of the sensing bulb of a thermal expansion valve that is attached to the evaporator tail coil on a horizontal run, what statement is true?Not learned 116. Which of the conditions listed does the blueprint symbol shown in the illustration representNot learned 117. The device illustrated would be best used as a __________Not learned 118. Which of the devices shown in the illustration is designed for both inside and outside measurementsNot learned 119. What is the drive arrangement of refrigeration compressor shown in figure "B" of the illustrationNot learned 120. In what remote temperature indicating system is a voltage generated by the magnitude of temperature difference between hot and cold junctions?Not learned 121. Which of the figures illustrated is not suitable for use as a hex head set screwNot learned 122. Which of the figures illustrated would be LEAST desirable for use as a set screwNot learned 123. Which of the figures shown in the illustration depicts an orthographic projectionNot learned 124. The function of item "7" shown in the illustration is to __________Not learned 125. The function of the section labeled "C" in the device illustrated is to provide a/an __________Not learned 126. Given that valve "14" is the king solenoid valve, which of the following statements is trueNot learned 127. In the illustrated huddling-chamber safety valve, what statement is true concerning the opening and closing forces acting upon the discNot learned 128. In the illustrated pneumatically operated, diaphragm actuated control valve, what statement is true concerning the opening and closing forces acting upon the control diaphragmNot learned 129. In the illustration, line "D" is a/an __________Not learned 130. In the illustration, line "C" is a __________Not learned 131. Which of the listed components of a hydraulic system would enable the pump to be temporarily shut down, and yet still provide an instantaneous source of hydraulic force?Not learned 132. Which of the listed valve types is typically used for the intermediate and high pressure stages of a reciprocating air compressor?Not learned 133. Which of the listed valve types is typically used for the low-pressure stage of a reciprocating air compressor?Not learned 134. The locking plates shown in the illustration are used in many marine applications. Which figure indicates the improper method for using these devicesNot learned 135. The low-pressure cut-out switch settings vary with the refrigerant used and the temperature application. If the low-pressure cut-out switch for a particular application is set with a cut-in pressure of 5 psig, what would be the cut-out pressure if the differential is 7.5 psig?Not learned 136. What is meant by a critical speed for rotating machinery?Not learned 137. What is meant by the term "deadband" as it applies to prime mover speed control governors?Not learned 138. What is the normal direction of flow through the device shown in the illustration while operating in the processing modeNot learned 139. When the oily-water separator, shown in the illustration, is in operation and processing clear bilge water, what should be the internal water levelNot learned 140. Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by __________.Not learned 141. What is the primary function of the devices shown in the illustrationNot learned 142. Probably the most useful troubleshooting tools used in a predictive maintenance management program for shipboard machinery are vibration meters, analyzers, and monitors. What is the term that represents the number of vibration cycles per unit time as a result of a part vibrating during its periodic or oscillatory motion?Not learned 143. A radiation pyrometer is sensitive to what form of radiation?Not learned 144. When reading a pressure that fluctuates severely on a direct-reading pressure gauge, what should be done?Not learned 145. Referring to the illustrated diagram, what type of HVAC system is shownNot learned 146. Referring to the illustrated huddling-chamber safety valve, what statement concerning the blowdown adjusting ring (B) is trueNot learned 147. Referring to the illustrated huddling-chamber safety valve, what statement is true concerning the adjustment of blowdownNot learned 148. Referring to the illustrated motor ship freshwater cooling system drawing, which cooling system has cooling water passing through passages within components that are continuously undergoing motionNot learned 149. Referring to the illustrated motorship freshwater cooling system drawing, which cooling system tanks are MOST likely to have oil separation capabilityNot learned 150. Referring to the illustrated motorship freshwater cooling system drawing, what statement is true concerning the evaporatorNot learned 151. Referring to the illustrated motor ship fresh water cooling system drawing, what statement is true concerning the jacket water heaterNot learned 152. Referring to the illustrated motorship freshwater cooling system drawing, what statement is true concerning the main engine jacket water cooling system heat recovery capability as associated with generating fresh waterNot learned 153. Referring to the illustrated pneumatically operated diaphragm actuated control valve, what statement is trueNot learned 154. Referring to the illustrated steam plant sea water cooling system drawing, which pump can be used to pump out the main machinery space bilge in a flooding emergencyNot learned 155. In a refrigeration system featuring low-side pumpdown prior to the automatic shutdown of the compressor, the temperature of the refrigerated space is controlled by the action of a thermostat wired to what device?Not learned 156. The shaft sleeve for the pump shown in the illustration is identified by which item numberNot learned 157. As shown in figure "B" in the illustrated block diagram of a central operating system configured for supervisory control, what is the function of the block "ANALOG (A-D MUX)"Not learned 158. As shown in figure "B" of the illustrated block diagram of a central operating system configured for supervisory control, which statement is true concerning the block "COMPUTER" with respect to closed-loop control processesNot learned 159. As shown in figure "B" of the illustrated self-contained recovery unit connection diagrams, what is the recovery method supported by the connection schemeNot learned 160. As shown in figure "A" of the illustrated block diagram of a central operating system configured for direct digital control, what does the output system block "DIGITAL CONTACT" representNot learned 161. As shown in figure "A" of the illustrated block diagram of a central operating system configured for direct digital control, what does the output system block "DIGITAL OUTPUT" representNot learned 162. When starting a reciprocating refrigeration compressor that has been shut down for a period of time, you should manually throttle which valve?Not learned 163. Which of the statements listed is applicable to the thermostatic expansion valve shown in the illustrationNot learned 164. What statement is true concerning critical speeds associated with rotating machinery?Not learned 165. What statement is true concerning the term "isochronous" as it applies to prime mover speed control governors?Not learned 166. Suppose the illustrated pneumatically operated diaphragm actuated control valve is used to control the fuel oil outlet temperature of a steam-heated heavy fuel oil heater by controlling the steam flow. What would be the result if there was a complete loss of pilot air being delivered to the valve actuatorNot learned 167. Suppose that a standard remote reading bourdon tube thermometer has a scale of 40 to 240°F. If the accuracy of the thermometer is plus or minus 1% of the span, what would the range of measured temperature be if the thermometer indicates 180°F?Not learned 168. The term "oil foaming" in refrigeration practice, is used to describe what event?Not learned 169. What type of pump is shown in the illustrationNot learned 170. A typical oily-water separator has three stages of separation. Which statement represents the correct sequential order of the stages?Not learned 171. Which of the projections represents the left side view of the object "X" in the illustrationNot learned 172. In comparing a semiconductor diode to a vacuum tube diode, what statement is true?Not learned 173. How is accidental flooding of the engine room bilges through the bilge system prevented?Not learned 174. Which of the illustrated motors has an open, drip-proof (ODP) motor enclosureNot learned 175. Probably the most useful troubleshooting tools used in a predictive maintenance management program for shipboard machinery are vibration meters, analyzers, and monitors. What is the term that represents the distance a mass travels in a given direction as a result of a part vibrating during its periodic or oscillatory motion?Not learned 176. What is the physical state and pressure condition of refrigerant as it enters the condenser of a typical refrigeration system?Not learned