Thermal efficiency of a gas turbine is in the range
A.50 to 60 percent
B.40 to 50 percent
C.30 to 40 percent
D.20 to 30 percent
Category: Turbo machines Mcqs
The effect of blade friction in a steam turbine is to
A.reheat the steam
B.increase the specific output
C.reduce exhaust pressure
D.reduce work done
Which of the following is a positive displacement rotory compressor?
A.Roots blower
B.Centrifugal compressor
C.Axial flow compressor
D.All of the above
Brayton cycle cannot be used in reciprocating engines even for same compression ratio and work output because
A.Otto cycle is more efficient
B.Brayton cycle is less efficient
C.Brayton cycle is for slow speed engines only
D.Large volume of low pressure gas cannot be efficiently handled in reciprocating engines
For a jet prepulsion unit, ideally the compressor work and turbine work are
A.unequal
B.equal
C.not related to each other
D.none of the above
Though there are no cyclic variations even then rotary compressors need precise balancing because
A.It is bulky in size
B.cooling arrangement does not exist
C.operating speeds are too high
D.it is driven by an electric motor
The flow on two sides of a normal shock wave is
A.subsonic
B.sonic
C.supersonic
D.supersonic on one side and subsonic on the other side
In air compressor performance curve a surge line represents
A.limits of compressor discharge
B.limit of compressor efficiency
C.limit of stable operation
D.lower critical speed of shaft
For efficient operation of axial flow compressors the blades are made
A.straight
B.slightly curved
C.aerofoil section
D.forward curved
In which of the following plant inferior quality fuel can be used?
A.Open cycle gas turbine with regeneration
B.Open cycle gas turbine with intercooling
C.Open cycle gas turbine with reheating and regeneration
D.Closed cycle gas turbine
