In diesel engines thermal efficiency may be expected in the range
A.10 – 15 percent
B.15 to 25 percent
C.25 to 30 percent
D.35 to 40 percent
E.50 percent
Category: Heat Engines Mcqs
Thermal efficiency of a standard Otto cycle for a compression ratio 5.5, will be
A.20%
B.35.40%
C.47.50%
D.50%
E.100%
If a steam injector fails to lift the water the trouble may not be due to
A.Too low steam pressure for list
B.Water pipe clogged
C.Water supply to cold
D.End of water pipe not submerged
The Clapeyron equation is applicable for
A.System in equilibrium
B.Change of state
C.Change of state when two phases are in equilibrium
D.Change of state when water and water vapours are involved
E.None of the above
Dew point temperature is an indication of
A.Moisture constant of air
B.Dryness of air
C.Lowest temperature where air and water vapour start separating
D.Condition of air
E.Condition of moisture in air
In a diesel engine the injection pressure is of the order of
A.40 kg/cm2
B.100 kg/cm2
C.500 kg/cm2
D.1000 kg/cm2
E.1500 kg/cm2
The work done in compressing 1 kg of air in compression will be least when the value of index is
A.1
B.1.1
C.1.2
D.1.41
E.1.5
If after some use the lower part, electrodes and beathing space of a spark plug are found coated by deposits of soot and carbon, the conclusion will be
A.Spark plug is of proper heat rating
B.Composition of mixture in the engine is correct
C.Spark plug is of too high heat rating
D.Spark advance is incorrect
E.Spark plug is short circuited
A 50 cfm compressor can
A.Compress 50 cu feet per min of free air
B.Compress 50 cu feet per min of standard air
C.Deliver 50 cu feet of compressed air at delivery pressure
D.Delivers 50 cu ft. per minute of compressed air
E.None of the above
Which of the following is false statement?
A.Fuel consumption of engine increases if silencer is choked
B.Fuel consumption of engines decreases if air filter is choked
C.Fuel consumption increases if exhaust valve is burnt
D.Fuel consumption increases if lean mixture is supplied
E.All of the above
