Turbo Machines 5

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Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Turbo Machines 5

Part 5: List for questions and answers of Turbo Machines

Q1.When working substance is released through nozzles, the direction of reaction will be
a) Clockwise
b) Counter clockwise
c) Either of (A) and (B) above
d) Direction depends on other design features

Q2.In a velocity compounded steam turbine, as steam moves along moving and guide blades
a) Pressure is low and velocity gradually decreases
b) Pressure gradually increases and velocity is low
c) Both pressure and velocity gradually decrease
d) Both pressure and velocity gradually increase

Q3.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

Q4.If stage efficiency is S, blade efficiency is B and nozzle efficiency in N, then
a) N = B.S
b) S = B.N
c) B = SN
d) BSN = 1

Q5.Bleeding in steam turbine refers to
a) Leakage of steam through bearings
b) Leakage of steam through packings
c) Purposely withdrawn steam for process application
d) Purposely withdrawn for feed water heating

Q6.Critical pressure for steam is
a) 185.85 kg/cm^2
b) 212.55 kg/cm^2
c) 225.65 kg/cm^2
d) 245.55 kg/cm^2

Q7.An ideal fluid for vapour turbine cycle should have
a) High critical temperature with low pressure
b) High critical temperature with high pressure
c) Low critical temperature with high pressure
d) Low critical temperature with low pressure

Q8.Which of the following fluid can be used in binary vapour cycle?
a) Mercury
b) Diphenyl oxide
c) Aluminium bromide
d) Any of the above

Q9.Which of the following loss in steam turbines is negligible?
a) Residual velocity loss
b) Leakage loss
c) Mechanical friction loss
d) Radiation loss

Q10.Which of the following is the least efficient method of governing steam turbines?
a) Nozzle control governing
b) Throttle governing
c) Bypass governing
d) Combined throttle and nozzle governing

Q11.Ljungstrom steam turbine is a
a) Radial flow turbine
b) Axial flow turbine
c) Mixed flow turbine
d) Any of the above

Q12.In a modern steam turbine, the steam rte is nearly
a) 1 kg/kwhr
b) 2 kg/kwhr
c) 4 kg/kwhr
d) 8 kg/kwhr

Q13.Which of the following rotary compressor has two shafts?
a) Axial flow compressor
b) Sliding vane compressor
c) Centrifugal compressor
d) Lobe type compressor

Q14.The ratio of outlet whirl velocity to blade velocity in case of centrifugal compressor is called
a) Slip factor
b) Velocity ratio
c) Blade efficiency
d) Diagram efficiency

Q15.The following property is the most important for material used for gas turbine blades
a) Fatigue
b) Strength against bending
c) Group
d) Strength against direct force

Q16.Which of the following is the smallest and lighest for generating a given amount of power
a) Steam power plant
b) Petrol engine
c) Diesel engine
d) Gas turbine plant

Q17.Generally, steam turbines in power stations operate at
a) 3000 rpm
b) 1500 rpm
c) 1000 rpm
d) 375 rpm

Q18.For gas turbine, compressors used are
a) Reciprocating type
b) Centrifugal type
c) Axial flow type
d) Lobe type

Q19.De Laval turbine is used for applications requiring
a) High power, high speed
b) High power, low speed
c) Low power, high speed
d) Low power, low speed

Q20.As a result of blade friction, the outlet relative velocity of impulse turbine compared to inlet relative velocity is
a) Nearly same
b) 2% less
c) 10% – 15% less
d) 30% less

Part 5: List for questions and answers of Turbo Machines

Q1. Answer: a

Q2. Answer: a

Q3. Answer: d

Q4. Answer: b

Q5. Answer: d

Q6. Answer: c

Q7. Answer: a

Q8. Answer: d

Q9. Answer: d

Q10. Answer: b

Q11. Answer: a

Q12. Answer: c

Q13. Answer: d

Q14. Answer: d

Q15. Answer: c

Q16. Answer: d

Q17. Answer: a

Q18. Answer: c

Q19. Answer: c

Q20. Answer: c