单选题Diesel fuel vapors （）.Acan not be ignited by a spark unless the vapor is in a confined spaceBare nontoxic in all concentrationsCcan not be ignited by a spark unless they are at their auto-ignition temperatureDare heavier than air
单选题
Diesel fuel vapors （）.
A
can not be ignited by a spark unless the vapor is in a confined space
B
are nontoxic in all concentrations
C
can not be ignited by a spark unless they are at their auto-ignition temperature
D
are heavier than air
参考解析
解析：
暂无解析
相关考题：
_______can be a direct cause of faulty operation of diesel engine fuel injection nozzles.A.Excessive fuel nozzle holder coolingB.Sediment in the fuel supplyC.Distortion of the fuel spray patternD.Improper atomization of the fuel
When fuel is injected late into a diesel engine cylinder_______.A.the exhaust will be clearB.fuel consumption will be lowC.all the fuel will be burned at top dead centerD.fuel consumption will be high
单选题Problems with the diesel engine fuel injection pump are usually caused by（）Aimproper adjustmentBcontaminated fuelCkinked fuel linesDexcessive engine vibration
单选题Starting a large low-speed propulsion diesel engine on diesel fuel during cold weather conditions, will be made easier by （）Aincreasing the quantity of starting airBincreasing the lube oil pressureCheating the engine fuel supplyDheating the engine coolant
单选题Mist detectors used on large low-speed main propulsion diesel engines monitor and check for the presence of （）.Afuel oil vapor at the sludge tank ventBunburned fuel vapors in the scavenge air receiverClube oil vapors in the crank caseDlube oil vapors in the engine room
单选题Duty officer informs us that the vessel is out of harbor and in “Full Ahead”We are going to run （）.Adiesel oil instead of fuel oilBfuel oil instead of diesel oilCdiesel oil instead fuel oilDfuel oil instead diesel oil
单选题The purpose of the programmed purge cycle on an automatically fired auxiliary boiler is to（）Acool the furnace to prevent pre-ignitionBremove explosive vapors from the furnaceCevaporate accumulated unburned fuel oilDprovide sufficient air in the furnace to allow ignition of the fuel
单选题Injection lag in a diesel engine may be caused by（）Aa higher cetane number of fuel oilBthe diesel fuel used having a high viscosityCmechanical rigidity in the lube pump mechanismDa decrease rigidity in the fuel pump delivery pressure
单选题Diesel fuel vapors （）.Acan not be ignited by a spark unless the vapor is in a confined spaceBare nontoxic in all concentrationsCcan not be ignited by a spark unless they are at their auto-ignition temperatureDare heavier than air
单选题The vapors given off by heated fuel oil are flammable, explosive, and （）Alighter than airBheavier than airCodorlessDnontoxic
单选题Significant retardation of a diesel engine fuel injection timing will result in （）Asmoother engine operationBadvanced fuel ignitionCincreased fuel economyDreduced engine power
单选题Faulty operation of diesel engine fuel injection nozzles can be a direct cause of（）.Aexcessive fuel nozzle holder coolingBsediment in the fuel supplyCdistortion of the fuel spray patternDimproper atomization of the fuel
单选题If the diesel fuel vapors present are within the flammable range （）.Athe vapor air mixture is too rich to burnBan explosion may occur if a source of ignition is presentCthe vapor air mixture is too lean to bum the upper explosiveDlimit has been exceeded
单选题Which of the following statements is least likely to cause the ignition of fuel vapors?（）AStatic electricityBAn open running electric motorCLoose wiringDExplosion proof lights
单选题What causes diesel fuel to be ignited in the cylinder of an operating diesel engine?（）ASpark plugBHeat of compressionCCarburetorDGlow plug
单选题Which may ignite fuel vapors?（）AStatic electricityBAn open and running motorCLoose wiringDAll of the above
单选题After the ship is out of the harbour and in “Full Speed”, well change （）.Ato fuel oil instead of diesel oilBfor fuel oil instead of diesel oilCto diesel oil into fuel oilDfor diesel oil into fuel oil
单选题Fuel injected into a diesel engines cylinder is ignited by （）.Athe heat compressed fuel/air mixture in the cylinderBthe fuel igniterCthe fuel injectorDthe fuel pump
单选题The most common diesel engine fuel system problems are caused by （）.Aincorrect adjustmentsBdirty fuelCbroken fuel linesDexcessive vibration
单选题The vapors given off by heated fuel oil are heavier than air and are（）.AodorlessBexplosiveCnontoxicDvisible
单选题A diesel engine burns （） a gasoline engine of the same capacity in the same period of time.Aas much fuel asBless fuel thanCless fuel asDmore fuel than
单选题When running a large, low-speed, main propulsion diesel engine on heavy fuel, which of the following precautions should be observed when switching back over to diesel oil?（）AThe diesel oil must never be allowed to mix with the heavy fuelBThe temperature of the fuel from the pre–heater should be gradually reduced after switching over the three–way valveCThe heating steam to the pre-heater should be secured as soon as the diesel fuel passes through the three-way valveDThe heating steam must be secured before the diesel oil passes through the three-way valve
单选题Which statement is TRUE concerning fuel vapors on a vessel（）.AFuel vapors gather in the lowest portions of the vesselBFuel vapors can only be ignited by an open flameCVent outlets should be located above the level of the carburetor air intakeDNone of the above
单选题Turbulence in a diesel engine cylinder is of major importance in providing （）.Aproper fuel meteringBcomplete fuel/air mixingCminimal fuel penetrationDproper fuel timing
单选题The most effective method in removing water from diesel fuel oil is by（）Acentrifuging the fuelBusing it in the engineCheating the fuel tanksDstarting the fuel
单选题What is LEAST likely to cause ignition of fuel vapors?（）.AStatic electricityBAn open running electric motorCLoose wiringDExplosion proof lights