单项选择题During which of the listed piston stroke of a four-stroke/cycle diesel engine, is the piston moving downward?()

A.Intake stroke
B.Compression stroke
C.Exhaust stroke
D.Pumping stroke


您可能感兴趣的试卷

你可能感兴趣的试题

1.单项选择题A piston is at bottom dead center when it is()

A.opening the exhaust ports
B.closing the fuel ports
C.farthest from the cylinder head
D.nearest to the cylinder head

2.单项选择题The average pressure exerted on piston during each power stroke is termed()

A.indicated horsepower
B.mean effective pressure
C.exhaust back pressure
D.compression pressure

3.单项选择题If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two-stroke/cycle diesel engine will develop approximately()

A.the same indicated horsepower as a four-stroke/cycle engine
B.twice the indicated horsepower as a four-stroke/cycle engine
C.one half indicated horsepower as a four-stroke/cycle engine
D.one power stroke for every two crankshaft revolutions

4.单项选择题In comparing engines of equal horsepower, higher exhaust gas temperatures occur in a/an()

A.opposed-piston engine
B.double-acting engine
C.two-stroke/cycle engine
D.four-stroke/cycle engine

5.单项选择题A disadvantage of a two-stroke/cycle diesel engine is()

A.more power strokes per revolution
B.the use of scavenge air
C.more complicated valve gear
D.higher working temperature of the piston and cylinder

6.单项选择题Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of ()

A.less even torque
B.higher cylinder head temperatures
C.fewer power strokes per revolution
D.greater weight/size requirements

7.单项选择题A disadvantage of a four-stroke/cycle diesel engine is ()

A.higher working temperature of piston and cylinder
B.the use of scavenge ports
C.fewer power strokes per revolution of the crankshaft
D.part of the fuel is burned as the piston is moving away from top dead center

8.单项选择题The cubic inch(or liter) displacement of a cylinder is determined by the diameter of the piston and the ()

A.length of the crankshaft
B.volume of the clearance space
C.weight of piston
D.length of the stroke

9.单项选择题(Piston area)X(Piston stroke)K(numbers of the cylinders)=engine()

A.brake horsepower
B.displacement
C.cylinder volume
D.cylinder clearance

10.单项选择题Which of the listed conditions will affective pressure the most in the cylinder of a diesel engine?()

A.TBN of the lubricating oil
B.Temperature of the lube oil
C.Completeness in the mixing of the fuel and air
D.Temperature of the cooling (sea) water