Turbo Machines 6

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Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Turbo Machines 6

Part 6: List for questions and answers of Turbo Machines

Q1.Maximum delivery pressure in a rotary air compressor is of the order of
a) 6 KSC
b) 10 KSC
c) 16 KSC
d) 25 KSC

Q2.Efficiency of gas turbine is increased by
a) Reheating
b) Intercooling
c) Adding a regenerator
d) All of the above

Q3Most serious energy loss in reaction steam turbine
a) Steam leakage between diaphragm and shaft
b) Leakage over blade ends through radia clearance passages
c) Frictional resistance between steam and nozzle side
d) Impact loss as steam enters moving blades

Q4.Basic closed cycle for gas turbine is
a) Carnot cycle
b) Rankine cycle
c) Brayton cycle
d) None of the above

Q5.The work ratio of closed cycle gas turbine plant with fixed top temperature of the cycle and fixed pressure ratio rp
a) Increases with increase in an inlet temperature to compressor
b) Increases with decrease in an inlet temperature to compressor
c) Remain same irrespective of inlet temperature to compressor
d) None of the above

Q6.Thermal efficiency of closed cycle gas turbine plant increases by
a) Reheating
b) Intercooling
c) Regenerator
d) All of the above

Q7.With increase in pressure ratio, thermal efficiency of a simple gas turbine plant with fixed turbine inlet temperature
a) Increases
b) Decreases
c) First increases and then decreases
d) None of the above

Q8.With ideal regenerative heat exchanger, the thermal efficiency of gas turbine cycle is
a) Equal to work ratio
b) Is less than work ratio
c) Is more than work ratio
d) None of the above

Q9.In a two stage gas turbine plant reheating after first stage
a) Increases thermal efficiency
b) Decreases thermal efficiency
c) Doses not affect thermal efficiency
d) None of the above

Q10.In a two stage gas turbine plant, reheating after first stage
a) Increases work ratio
b) Decreases work ratio
c) Does not affect work ratio
d) None of the above

Q11.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

Q12.Greater the difference between jet velocity and aeroplane velocity
a) Greater the propulsive efficiency
b) Lesser the propulsive efficiency
c) Unaffected is the propulsive efficiency
d) None of the above

Q13.What is the head of water available at turbine inlet in hydro-electric power plant called?
a) Head race
b) Tail race
c) Gross head
d) Net head

Q14.Gross head is the difference between _________
a) Head race and tail race
b) Head race and net head
c) Head race and friction losses
d) Net head and friction losses

Q15.What is runaway speed of the runner of Pelton wheel?
a) Maximum unsafe speed of the runner due to sudden increase in load on turbine
b) Minimum safe speed of the runner due to sudden increase in load on turbine
c) Maximum unsafe speed of the runner due to sudden decrease in load on turbine
d) Minimum safe speed of the runner due to sudden decrease in load on turbine

Q16.The gates of aerofoil section in between the outer and inner ring of guide wheel are called as ________
a) Guide gates
b) Guide vanes
c) Scrolling gates
d) Scrolling vanes

Q17.Which of the following components of reaction turbine increases the head on the turbine by an amount equal to the height of runner outlet above the tail race?
a) Scroll casing
b) Guide vanes
c) Moving vanes
d) Draft tube

Q18.In which type of turbine, the runner needs to be run full of water?
a) Impulse turbine
b) Reaction turbine
c) Both a. And b.
d) None of the above

Q19.As the reaction turbine works on the principle of impulse and reaction, it follows the law of _______
a) Impulse momentum
b) Angular momentum
c) Both a. And b.
d) None of the above

Q20.Discharge capacity of the reciprocating pump is __________ that of the centrifugal pump
a) Higher than
b) Lower than
c) Same as
d) Unpredictable

Part 6: List for questions and answers of Turbo Machines

Q1. Answer: c

Q2. Answer: d

Q3. Answer: d

Q4. Answer: c

Q5. Answer: b

Q6. Answer: d

Q7. Answer: c

Q8. Answer: a

Q9. Answer: b

Q10. Answer: a

Q11. Answer: b

Q12. Answer: b

Q13. Answer: d

Q14. Answer: a

Q15. Answer: c

Q16. Answer: b

Q17. Answer: d

Q18. Answer: b

Q19. Answer: b

Q20. Answer: b