A.Chemical energy B.Mechanical energy C.Thermal energy D.Electrical energy
单项选择题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.over-travel in the rudder angle indicator D.lost motion in the rams
单项选择题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 toan abnormally low flow B.The pump packing gland overheats after short operating periods C.The motor over-current protective device continually shuts the pump down D.Pounding noises can be heard at the pump suction chest
单项选择题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
单项选择题If the discharge valves on a refrigeration compressor are leaking badly, the compressor should ().
A.run continuously B.not start C.have high discharge pressure D.short cycle on the high pressure switch
单项选择题Which of the following terms could be applied to the simple definition the energy of motion?()
A.Electrical energy B.Thermal energy C.Potential energy D.Kinetic energy