1. Normal standard of compression for rotary compressor is
Correct : C. isentropic compression
2. The continuity equation in compressible fluids is derived on the basis of
Correct : B. conservation of mass
3. Gas turbine used in aircraft is of
Correct : D. open cycle type
4. With increase in pressure ratio, thermal efficiency of a simple gas turbine plant with fixed turbine inlet temperature
Correct : C. first increases and then decreases
5. The ratio of actual velocity to the local velocity of sound is called
Correct : C. Mach number
6. Actual gas turbine cycle is different from ideal cycle because
Correct : D. all of the above
7. Gas turbines are taken to
Correct : D. All of the above
8. Which component of a gas turbine consumes maximum power?
Correct : D. Compressor
9. Critical pressure for steam is
Correct : C. 225.65 kg/cm2
10. Which of the following preferred for supercharging of internal combustion engines?
Correct : A. Roots blower
11. Which gas turbine has lest weight per bhp developed?
Correct : A. Simple open cycle gas turbine
12. In which of the following plant inferior quality fuel can be used?
Correct : C. Closed cycle gas turbine
13. Which of the following loss in steam turbines is negligible?
Correct : B. Radiation loss
14. Most serious energy loss in reaction steam turbine
Correct : D. Leakage over blade ends through radia clearance passages
15. An axial flow compressor is suitable for
Correct : B. high volume flow rates with a small pressure rise
16. For a jet prepulsion unit, ideally the compressor work and turbine work are
Correct : B. equal
17. Stalling of the blades of axial flow compressor is
Correct : C. the reduction in lift force at higher angle of incidence
18. In a two stage gas turbine plant reheating after first stage
Correct : B. decreases thermal efficiency
19. In a nozzle if back pressure is equal to inlet pressure
Correct : B. no flow occurs
20. The source of power for driving a turbocharger is
Correct : C. kinetic energy of exhaust gases from the engine
21. The diverging portion of the nozzle acts as a diffuser for
Correct : A. the subsonic flow
22. Efficiency of gas turbine is increased by
Correct : D. All of the above
23. Curtis turbine is
Correct : A. a velocity pressure compounded turbine
24. Which of the following is a pressure compounded turbine?
Correct : C. Rateau turbine
25. The work ratio of closed cycle gas turbine plant with fixed top temperature of the cycle and fixed pressure ratio rp
Correct : B. increases with decrease in an inlet temperature to compresor
26. In an axial flow compressor, the pressure rise occurs in
Correct : C. Both fixed and moving blades
27. Surging is
Correct : A. an unsteady, periodic and reversal of flow in the compressor
28. A regenerator can be used on
Correct : C. both open as well as closed cycle gas turbines
29. Maximum delivery pressure in a rotary air compressor is of the order of
Correct : B. 16 KSC
30. An axial flow compressor has
Correct : C. larger blades at gas entry and smaller blades at exit
31. In a gas turbine cycle regenerator is used to
Correct : B. heat air supplied to combustion chamber
32. In a nozzle, once the critical conditions are achieved at the throat, than which of the following remains constant
Correct : D. All of the above
33. The range of compression ratio in a gas turbine is
Correct : B. 5 to 8
34. In a hot wire anemometer the rate of heat loss from sensing element is a function of
Correct : C. velocity of flow
35. When working substance is released through nozzles, the direction of reaction will be
Correct : B. counter clockwise
36. Though there are no cyclic variations even then rotary compressors need precise balancing because
Correct : D. operating speeds are too high
37. In a velocity compounded steam turbine, as steam moves along moving and guide blades
Correct : D. pressure is low and velocity gradually decreases
38. Generally, steam turbines in power stations operate at
Correct : A. 3000 rpm
39. An ideal fluid for vapour turbine cycle should have
Correct : B. high critical temperature with low pressure
40. Overall efficiency of a gas turbine is
Correct : A. less than Diesel cycle efficiency
41. In gas turbines, intercooling results in
Correct : C. increase in net output as well as thermal efficiency
42. Maximum delivery pressure in case of rotary compressors is usually restricted to
Correct : B. 10 atmospheres
43. For efficient operation of axial flow compressors the blades are made
Correct : A. aerofoil section
44. Under standard atmospheric condition, the velocity of air is
Correct : C. 336 m/s
45. A diffuser
Correct : C. converts kinetic energy into thermal energy
46. Which of the following is a positive displacement rotory compressor?
Correct : A. Roots blower
47. In which of the following heat exchanger, heat is extracted from air?
Correct : C. Intercooler
48. The following property is the most important for material used for gas turbine blades
Correct : D. Group
49. Which of the following fluid can be used in binary vapour cycle?
Correct : D. any of the above
50. A control volume has an inlet area of 0.1 m2 and exit area of 0.05 m2. The density is 3.89 kg/m2 and constant. If the inlet velocity is 30 m/s, the force on the control volume will be
Correct : A. 350 N
51. In a reheating gas turbine cycle, reheating is done
Correct : C. in separate combustion chamber
52. The ratio of outlet whirl velocity to blade velocity in case of centrifugal compressor is called
Correct : C. slip factor
53. Thermal efficiency of a gas turbine is in the range
Correct : D. 30 to 40 percent
54. A roots blower compresses 0.06 cubic metres of air from 1.0 bar to 1.45 bar per revolution. The compressor efficiency is nearly
Correct : C. 87%
55. Basic closed cycle for gas turbine is
Correct : C. Brayton cycle
56. The advantage of a gas turbine over a reciprocating engine is
Correct : D. all of the above
57. A diffuser is used to
Correct : D. decrease velocity and increase pressure
58. Air fuel ratio for a gas turbine is closer to
Correct : A. 60 ; 1
59. Which of the following steam turbine has identical fixed and moving blades?
Correct : C. Parson's turbine
60. Bleeding in steam turbine refers to
Correct : C. purposely withdrawn for feed water heating
61. As a result of blade friction, the outlet relative velocity of impulse turbine compared to inlet relative velocity is
Correct : C. 10% - 15% less
62. As there is plenty of time for heat transfer across the walls, the flow in long pipes at low velocities attains
Correct : B. isothermal conditions
63. The normal shock wave in compressible flow is analogous to
Correct : C. hydraulic jump in channel flow
64. Greater the difference between jet velocity and aeroplane velocity
Correct : B. Lesser the propulsive efficiency
65. If stage efficiency is S, blade efficiency is B and nozzle efficiency in N, then
Correct : C. S = B.N
66. Choking is
Correct : C. fixed mass flow rate regardless of pressure ratio
67. The advantage of closed cycle gas turbine over open cycle gas turbine is
Correct : D. All of the above
68. Brayton cycle cannot be used in reciprocating engines even for same compression ratio and work output because
Correct : A. Large volume of low pressure gas cannot be efficiently handled in reciprocating engines
69. Working medium for closed cycle gas turbine should have
Correct : C. higher adiabatic index
70. Thermal efficiency of a gas turbine cycle can be improved by
Correct : D. any of the above
71. Thermal efficiency of closed cycle gas turbine plant increases by
Correct : D. All of the above
72. For gas turbine, compressors used are
Correct : C. Axial flow type
73. Which of the following is the least efficient method of governing steam turbines?
Correct : B. Throttle governing
74. The effect of blade friction in a steam turbine is to
Correct : B. reduce work done
75. In rotory compressors, the ratio of isentropic work to Eulers work is known as
Correct : D. pressure coefficient
76. Ljungstrom steam turbine is a
Correct : A. radial flow turbine
77. A constant volume combustion gas turbine operates on
Correct : D. Atkinson cycle
78. All of the following are positive displacement compressors EXCEPT
Correct : D. Axial flow compressor
79. De Laval turbine is used for applications requiring
Correct : B. Low power, high speed
80. Which type of rotary compressor is used in oil fired furnaces?
Correct : D. Centrifugal blower
81. In a two stage gas turbine plant, reheating after first stage
Correct : A. increases work ratio
82. The efficiency of a simple open cycle gas turbine depends upon
Correct : D. All of the above
83. In a nozzle under choked flow conditions pressure waves travel, in the divergent portion, at
Correct : C. sonic speed
84. Which of the following is a displacement compressors?
Correct : D. Vane blower
85. With ideal regencrative heat exchanger, the thermal efficiency of gas turbine cycle is
Correct : A. equal to work ratio
86. In a modern steam turbine, the steam rte is nearly
Correct : C. 4 kg/kWhr
87. In air compressor performance curve a surge line represents
Correct : D. limit of stable operation
88. In rotary compressors, slip factor is the ratio of
Correct : C. outlet whirl velocity to the blade velocity
89. In a gas turbine combined cycle plant, a waste heat boiler is used to
Correct : C. recover heat form exhaust gases
90. The flow on two sides of a normal shock wave is
Correct : A. supersonic on one side and subsonic on the other side
91. Which of the following rotary compressor has two shafts?