单选题The relative air pressure in the inlet manifold of a turbocharged diesel engine is usually（）A greater than the average exhaust manifold pressureB less than the average exhaust manifold pressureC greater at the turbine wheel than at the impellerD greate

Which of the following problems should be taken when cleaning the air filter on a diesel engine equipped with a turbocharger? .

A.Reduce engine speed to idle before removing the filter

B.Soak the dirty filter in kerosene only

C.Blow out the air inlet with compressed air

D.Cover the air inlet after removing the filter

The expression THE AIR IS SATURATED means ______.

A.the relative humidity is 100%

B.the vapor pressure is at its minimum for the prevailing temperature

C.precipitation has commenced

D.cloud cover is 100%

A.Close the inlet and outletvalves for diesel oil

B.Open the air nozzles in the secondary combustion chamber until it stops

C.Open the air nozzles in the primary combustion chamber until it stops

D.Close inlet valve for pressurized air

The relative air pressure in the inlet manifold of a turbocharged diesel engine is usually______.

A.greater than the average exhaust manifold pressure

B.less than the average exhaust manifold pressure

C.greater at the turbine wheel than at the impeller

D.greater at reduced engine speed

The dew point is reached when the ______.

A.temperature of the air equals the temperature of the seawater

B.atmospheric pressure is 14.7 lbs. per square inch

C.relative humidity reaches 50%

D.air becomes saturated with water vapor

The high air velocity leaving the compressor of an exhaust gas turbocharger is converted to pressure in the_______.

A.inlet nozzle ring

B.turbine wheel blade

C.diffuser passages

D.inlet volute