Turbo Machines 4

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Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Turbo Machines 4

Part 4: List for questions and answers of Turbo Machines

Q1.Normal standard of compression for rotary compressor is
a) Adiabatic compression
b) Polytropic compression
c) Isentropic compression
d) Constant pressure compression

Q2.Though there is 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

Q3.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

Q4.Curtis turbine is
a) In impulse turbine
b) A velocity compounded turbine
c) A pressure compounded turbine
d) A velocity pressure compounded turbine

Q5.The source of power for driving a turbocharger is
a) Kinetic energy of exhaust gases from the engine
b) Chemical energy of exhaust gases
c) Air motor
d) Electric motor

Q6.Maximum delivery pressure in case of rotary compressors is usually restricted to
a) 2 atmospheres
b) 5 atmospheres
c) 10 atmospheres
d) 20 atmospheres

Q7.Which of the following is a displacement compressors?
a) Reciprocating air compressor
b) Vane blower
c) Centrifugal blower
d) Axial flow compressors

Q8.Which type of rotary compressor is used in oil fired furnaces?
a) Sliding vane type blower
b) Screw compressor
c) Axial flow compressor
d) Centrifugal blower

Q9.In rotary compressors, slip factor is the ratio of
a) Stagnation pressure to static pressure
b) Isentropic work done to actual work
c) Outlet whirl velocity to the blade velocity
d) None of the above

Q10.In rotary compressors, the ratio of isentropic work to Euler’s work is known as
a) Slip factor
b) Work factor
c) Pressure coefficient
d) Degree of reaction

Q11.Stalling of the blades of axial flow compressor is
a) An unsteady periodic and reversal of flow
b) The fixed mass flow rate regardless of pressure ratio
c) The reduction in lift force at higher angle of incidence
d) None of the above

Q12.Surging is
a) An unsteady, periodic and reversal of flow in the compressor
b) The fixed mass flow rate regardless of pressure ratio
c) The reduction in lift force at higher angles of incidence
d) None of the above

Q13.Choking is
a) Variation of mass flow rate in proportion to pressure ratio
b) Variation of mass flow rate in inverse proportion to pressure ratio
c) Fixed mass flow rate regardless of pressure ratio
d) None of the above

Q14.Gas turbines are taken to
a) The gasoline and diesel engines in its working medium
b) The petrol and diesel engines in its internal combustion
c) The steam turbine in its aspect of steady flow of the working medium
d) All of the above

Q15.Which gas turbine has lest weight per bhp developed?
a) Simple open cycle gas turbine
b) Open cycle gas turbine with intercooling and reheating
c) Open cycle gas turbine with intercooling, reheating and regeneration
d) Closed cycle gas turbine

Q16.In gas turbines, intercooling results in
a) Decrease in net output as well as thermal efficiency
b) Decrease in net output and increase in thermal efficiency
c) Increase in net output but decrease in thermal efficiency
d) Increase in net output as well as thermal efficiency

Q17.Working medium for closed cycle gas turbine should have
a) High molecular weight
b) Low specific volume
c) Higher adiabatic index
d) Lower specific speed

Q18.The advantage of closed cycle gas turbine over open cycle gas turbine is
a) No contamination of working substance with combustion gases
b) Inferior quality fuel can be used
c) Low maintenance costs
d) All of the above

Q19.The range of compression ratio in a gas turbine is
a) 3 to 6
b) 5 to 8
c) 8 to 12
d) 12 to 22

Q20.A constant volume combustion gas turbine operates on
a) Ericsson cycle
b) Brayton cycle
c) Joule cycle
d) Atkinson cycle

Part 4: List for questions and answers of Turbo Machines

Q1. Answer: c

Q2. Answer: c

Q3. Answer: c

Q4. Answer: d

Q5. Answer: a

Q6. Answer:

Q7. Answer: b

Q8. Answer: d

Q9. Answer: c

Q10. Answer: c

Q11. Answer: c

Q12. Answer: a

Q13. Answer: c

Q14. Answer: d

Q15. Answer: a

Q16. Answer: d

Q17. Answer: c

Q18. Answer: d

Q19. Answer: b

Q20. Answer: d