A.Sealed motors
B.Drip proof motors
C.Enclosed motors
D.Watertight motors
您可能感興趣的試卷
你可能感興趣的試題
A.both meters in series with the resistance
B.both meters in parallel with the resistance
C.the ammeter in series and the voltmeter in parallel with the resistance
D.the ammeter in parallel and the voltmeter in series with the resistance
A.open circuit
B.short circuit
C.polarized ground
D.ground reference point
A.Contactors control current and relays control voltage
B.A relay is series connected and a contactor is parallel connected
C.Contactors can handle heavier loads than relays
D.Contactors are made from silver and relays are made from copper
A.short proof
B.ground proof
C.explosion proof
D.overload proof
A.AC
B.DC
C.generator
D.fresh water generator
最新試題
A purge recovery system is used in a centrifugal air conditioning or refrigeration system to （）
Which of the diesel engine components listed increase air density and helps to improve engine operating efficiency?（）
The flash point of a residual fuel oil should be used to determine the highest temperature to which oil may be heated（）
If two A.C.generators are to be operated in parallel, the load is distributed evenly by（）
The main purpose of port State control is not to（）
The shipboard oil pollution emergency plan will be invalid after （）
To shut down a diesel engine after it exceeds the set maximum speed，which type of device listed should be used?（）
When does auxiliary burner of incinerator put into operation? （）Ⅰ. start incinerator when it is coldⅡ. the sludge for dealing with is littleⅢ. the sludge for dealing with is largeⅣ. the water and impurity in sludge are too muchⅤ. the temperature in incinerator is lowⅥ. dealing with little solid rubbish
One of the reasons that cause oil flowed from sludge outlet of a self-cleaning separator is（）
The ISPS Code consists of a mandatory section-Part A, which shows（）