【正文】 1864 The rate of heat transfer between the hot and cold fluids passing through a shellandtube type heat exchanger will_____. A. remain constant along the tube39。 ? A. Electrical energy B. Thermal energy C. Potential energy D. Kiic energy 1842 If the discharge valves on a refrigeration pressor are leaking badly, the pressor should_____. A. run continuously B. not start C. have high discharge pressure D. short cycle on the high pressure switch 1843 Increasing the speed of a centrifugal pump will result in an increase in its capacity. Another means of increasing the capacity of a centrifugal pump is to increase the _____. A. diameter of the discharge piping, with all other factors remaining the same B. diameter of the suction piping, with all other factors remaining the same C. width of the impeller only D. diameter of the impeller 1844 Excessive air leakage into the suction side of a centrifugal pump would be indicated by which of the following operational problems? A. The pump delivers full capacity when started, but gradually slackens off to an abnormally low flow. B. The pump packing gland overheats after short operating periods. C. The motor overcurrent protective device continually shuts the pump down. D. Pounding noises can be heard at the pump suction chest. 1845 While inspecting the steering system at sea, you should check for_____. A. air bubbles in the sight glass B. any leaks in the system C. overtravel in the rudder angle indicator D. lost motion in the rams 1846 Which of the following forms of energy is demonstrated釋放 through the process of bustion? A. Chemical energy B. Mechanical energy C. Thermal energy D. Electrical energy 1847 The capacity of a centrifugal pump can be increased by the installation of a larger diameter impeller. Another means of increasing the pump capacity is to_____. A. increase speed B. increase the size of the cardent assembly C. reduce wearing ring clearances D. change the pump to a close coupled arrangement 1848 A spur gear pump should be operated with the discharge valves_____. A. slightly opened B. throttled C. fully opened D. halfway opened 1849 The oil in a cargo winch gear box should be sampled periodically to_____. A. prevent the gear box from leaking B. prevent the oil from being inflammable C. make sure it has not bee contaminated D. make sure the motor bearings are lubricated 1850 When the steering gear is in operation, you should_____. A. check hydraulic oil levels every hour B. check the rams for overheating C. check for excessive oil leakage from rams D. drain water from telemeters cylinders each watch 1851 An excessive charge of refrigerant in an aircooled refrigeration system can cause _____. A. oil foaming in the pressor B. higher than normal suction and discharge pressures with a higher box temperature C. higher than normal discharge pressure with a normal box temperature D. the pressor to run continuously 1852 The output volume of a positive fixed displacement pump can be changed only by_____. A. changing the angle of the tilting plate B. changing the speed of the pump C. moving the slide block and rotor D. moving the shaft turnsion block 1853 If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should_____. A. add fluid that is the same color as the fluid in the reservoir B. add turbine oil because it is always a good substitute C. add any oil that has the same viscosity as the hydraulic fluid D. check the winch manufacturer39。 D. flooding of the receiver 1839 In a refrigeration system equipped with a reciprocating pressor and a water cooled condensing unit, leaking pressor discharge valves will result in_____. A. refrigerant flooding of the pressor B. low suction pressure C. noisy pressor operation D. low head pressure 1840 The delivery rate of an axialpiston hydraulic pump is controlled by varying the position of the_____. A. sliding block B. pintle C. reaction ring D. tilting box or swash plate 1841 Which of the following terms could be applied to the simple definition the energy of motion39。s efficiency B. a danger of explosion exists whenever water is present in a pressor C. water causes erratic（ 不穩(wěn)定的）operation of pneumatic ponents D. the volumetric capacity of the first stage is reduced if water remains 1819 If a refrigeration system were short of refrigerant, the condition would result in_____. A. continuous running of the pressor B. high suction pressure C. high discharge pressure D. short cycling of the pressor on the water failure switch 1820When air bees trapped（收集） in the hydraulic fluid of a steering system, the_____. A. rudder will respond sluggishly B. hydraulic rams will overspeed C. sight glass will show bubbles D. ram relief valves will lift 1821 Before starting a reciprocating, steamdriven pump that has been idle for a period of time, you should_____. A. open the steam line root valve B. drain the steam cylinder C. close the steam cylinder drains D. open the liquid cylinder drains 1822 The air charge leaving an intercooler, or aftercooler of an air pressor can be expected to be_____. A. superheated B. supercooled C. at or below the dew point D. All of the above *1823 Noise in a refrigeration pressor can