10 Feb 2014

JET ENGINE - JUN 2003 SESSION.



TOTAL QUE 80                                                                     

1. Torque meter is used in
(a)    Turbofan
(b)   Turbo shaft
(c)    Turbo prop
(d)   All of the above

2. Mark correct statement
(a)    Throttle control & propeller control is interconnected I the ground operation
(b)   In flight propeller control is interconnected in the ground operation
(c)    ---------------------------------------------------------------------------------
(d)   Both 1 & 2

3. If throttle of constant speed propeller is reduced slightly
(a)    Pitch angle reduce
(b)   Pitch angle increase
(c)    Pitch angle remains same
(d)   Pitch angle will reverse

4. Antiicing operation check is viewed by
(a)    Fluctuation of RPM
(b)   Fluctuation of EPR
(c)    Flickering of antiicing valve
(d)   TGT increase

5. Notch in turbine blade is
(a)    To measure wear
(b)   Relieve stress
(c)    Giving thickness
(d)   Air seal

6. Aluminum propeller blade cleaning is done by
(a)    Acid
(b)   Caustic soda wash
(c)    None

7. Mark the correct statement
(a)    Governor speed progressively increases as load added
(b)   Governor speed progressively decreases as load added
(c)    Governor speed remains constant as load added
(d)   Governor speed remains constant as load removed



8. Mark the correct statement
(a)    Governor droop is decrease of speed when load added
(b)   Governor droop is increase of speed when load unloaded
(c)    Droop makes stable
(d)   All of the above

9. Mark the correct statement regarding ass flow rate
(a)    Proportional to pressure & inversely proportional to temperature
(b)   Proportional to pressure & temperature
(c)    Proportional to temperature & inversely proportional to pressure
(d)   Proportional to temperature & inversely proportional to square root to temperature

10. In modern APU
(a)    Load control valve can be adjusted only after shut down
(b)   Load control valve works in conjunction of surge valve
(c)    Clockwise rotation of trimming means increasing
(d)   All of the above

11. Compressure blade is loose fit due to
(a)    Reduce vibrational stress
(b)   Ease of removal
(c)    Temperature compensation
(d)   All of above

12. If EPR reads 2.4 then turbine discharge pressure is 2.4 times of
(a)    Inlet static pressure
(b)   Inlet ram pressure
(c)    Ambient pressure
(d)   Compressure inlet total pressure

13. Last chance filter in the oil system screen type
(a)    Cleared during engine overhaul
(b)   Prevent clogging of jet
(c)    Cleaner during 100 hrs inspection
(d)   Both 1 & 2

14. Engine preservation depends on
(a)    Times remains inactive
(b)   Duration of preservation
(c)    Depends on engine rotation
(d)   All of the above


15. Mark correct statement regarding double entry centrifugal compressor
(a)    Prevent tip velocity loss
(b)   Air entry from both side of comrpessure
(c)    Required big inlet chamber
(d)   All of the above

16. After burner thrust augmentation
(a)    Thrust of basic engine can be increased
(b)   Thrust increase by after burner for take off climb for military aircraft
(c)    Both 1 & 2 are correct
(d)   None of the above

17. If JPT is high then water is injected in
(a)    Inlet
(b)   Diffuser
(c)    Both
(d)   Combustion




18. If water is injected in the diffuser
(a)    Mass flow increased in entire engine
(b)   Less pr. & temp drop in turbine hence more pr. in tail
(c)    ----------------------------------
(d)   All are correct

19. I water in injected in the inlet and diffusers
(a)    N1 shift towards surge
(b)   N1 shift away surge
(c)    N2 shift away surge
(d)   Both N1 & N2 away surge

20. Variable propelling nozzle is used due reduce TSEC
(a)    By pass engine
(b)   After burner
(c)    Water injection
(d)   All of above

21. Velocity in combustion chamber is reduced
(a)    Increased static pr
(b)   Ease of burning
(c)    ----------------------
(d)   ----------------------

22. Stable combustion means
(a)    Low emission
(b)   Combustion alighted over long range
(c)    As 1 & 2
(d)   --------------------------------------------

23. In can annular liner
(a)    Continues shroud
(b)   Circular & outer
(c)    Inner & cylindrical
(d)   As 2 & 3










24. Mark incorrect statement regarding combustion chamber drain valve
(a)    Mechanically operation by spring force
(b)   Failure of valve gives false start
(c)    Located in LH or RH side bottom
(d)   None of the above

25. Canted vanes in the first few stage of compressor
(a)    Increase pressure
(b)   Increase velocity
(c)    Increase temperature
(d)   Reduce boundary layer separation

26. Knife edge (profile) blade
(a)    Wears & sets tip clerance
(b)   Used in supersonic aircraft
(c)    Is not used
(d)   Used in turbine blade

27. Repair of compressure or fan blade is called
(a)    Grinding
(b)   Brinelling
(c)    Galling
(d)   Blending

28. Balancing of compressure
(a)    Individual stage is balanced
(b)   As a unit balanced
(c)    Both 1 & 2
(d)   Not required

29. Turbine blade design is based on
(a)    Corrosion resistance
(b)   Creep
(c)    Fatigue & vibration resistance
(d)   Both 2 & 3

30. Fatigue stress causes
(a)    Elongation of blade
(b)   Crack in LE & TE
(c)    Change of shape
(d)   All of above





31. Mark current statement regarding radial inflow turbine
(a)    Air enters at eye & leaves at radial outward
(b)   Used in big engine
(c)    Air enters at peripheral nozzle & flows radial inward
(d)   As 2 & 3

32. Function of NGV is
(a)    Convert PE to KE
(b)   Convert KE to PE
(c)    Directs air perpendicular to bucket
(d)   As 1 & 3

33. In pure turbojet engine temperature drop across turbine is
(a)    Same as compressor
(b)   About same as compressor
(c)    Higher than compressor very low than compressor
(d)   Very low than compressor

34. For load balancing in the turbine rear stages
(a)    More turbine area is required
(b)   More length is required
(c)    Less turbine area is required
(d)   As 1 & 2

35. If exhaust nozzle area is decreased
(a)    CDP increases
(b)   CDP decreases
(c)    SFC decreases
(d)   As 1 & 3

36. What component prevent stall during low speed ground operation
(a)    Bleed valve
(b)   P & D Valve
(c)    Chock Valve
(d)   As 1 & 2

37. During starting starter & fuel flow are ok, but hung start cuase is
(a)    CDP sensor loss
(b)   CIT loss
(c)    -----------
(d)   -----------------------

38. Mark correct statement
(a)    Engine running at high RPM & CDP lost then stabilize at idle
(b)   Engine running at idle RPM & CDP lost then stabilize at high RPM
(c)    CDP lost during starting it is a hung start 
(d)   All are correct

39. Minimum fuel flow is critical
(a)    Acceleration
(b)   Deceleration
(c)    Idle
(d)   Ground run

40. Which component is not installed in the engine?
(a)    Fuel pump
(b)   FCOC
(c)    Filter
(d)   Boost pump

41. Deareator is located in
(a)    Scavenge sub system
(b)   Pressure sub system
(c)    Inlet of the pump
(d)   Oil tank

42. After engine shut down oil found in the exhaust
(a)    Seal failure
(b)   Bearing seal failure
(c)    Replace engine
(d)   Air pressurization seal failure

43. Air tight seal is
(a)    Carbon seal
(b)   Ring seal
(c)    Multi grove seal
(d)   Threaded seal





44. Mark correct statement
(a)    Pressure pump capacity is scavenge pump
(b)   Scavenge pump capacity is more pressure pump
(c)    Both pumps capacity 
(d)   As 3 & both are located in oil system

45. Mg is found in SOAP analysis then failure is
(a)    Gear
(b)   Gear box
(c)    Bearing
(d)   Bearing shaft

46. Oil SOAP analysis then failure is
(a)    Pin point impending failure
(b)   Take sample for entire engine life
(c)    First sample gives food analysis
(d)   As 1 & 2

47. Property of lubricating oil is
(a)    High flash point
(b)   Low flash point
(c)    High pore point
(d)   Low viscosity index

48. Synthetic oil is used in turbojet engine
(a)    Corrosion resistance
(b)   Low carbon / wax formation
(c)    High temperature operation
(d)   All the above

49. Input to hydro-mechanical FCU
(a)    Burner pressure compressure inlet pressure EGT
(b)   Burner pressure compressure inlet pressure, RPM
(c)    ----------------------------------------------------------
(d)   ----------------------------------------------------------


50. In part EEC system
(a)    Control till part throttle and then switch off.
(b)   -----------------------------------------------------
(c)    -----------------------------------------------------
(d)   It is like FADEC

51. In supervisory EEC
(a)    Develops command
(b)   Control standard hydro-mechanical system
(c)    Control valve
(d)   As 1 & 2

52. Acceleration & deceleration control is
(a)    Flam blow out
(b)   To prevent over flow
(c)    For max speed
(d)   -------------------------

53. High power to weight ratio is in which starter
(a)    Electric starter
(b)   Starter generator
(c)    Air turbine starter
(d)   Pawl & ratchet starter

54. White repair AME increased length of thermo-couple
(a)    Over read
(b)   Under read
(c)    No effect 
(d)   Over read at hi temperature

55. During feathering pitch angle
(a)    Course & higher
(b)   Low pitch
(c)    Course
(d)   Negative

56. Propeller lock LP solenoid
(a)    -------------------
(b)   -------------------
(c)    -------------------
(d)   -------------------





57. EGT gauge yellow amber arc
(a)    Maximum continues to maximum permissible
(b)   Minimum to continue
(c)    Maximum
(d)   As 1 & 2

58. Torque is measured by
(a)    Helical gear
(b)   Rack & pinion
(c)    Spur gear
(d)   Planetary gear

59. As altitude increases stall margin
(a)    Reinold No. Effect
(b)   Increases that’s why aircraft flying only at high altitude
(c)    Decreases
(d)   ---------------------------------------------------------------------
60. Trimble coil in ignition system
(a)    Connected parallel to primary capacitor
(b)   Connected series to primary capacitor
(c)    Not used in ignition system
(d)   Used in starting system

61. Shaft engine forward bearing is
(a)    Baller bearing
(b)   Roller bearing
(c)    1 + is locator bearings
(d)   2 + is takes radial load

62. MCS
(a)    APU generator frequency is maintained by CSD and is constant speed rated
(b)   APU does not have CSD in its operation and is constant speed rated
(c)    APU generator requires axial flow compressor and is constant speed rated
(d)   Both B and C are correct

63. MCS
(a)    In turbo-jet TSFC increases as airspeed increases
(b)   In turbo prop TSFC decreases as airspeed increases
(c)    In turbo prop TSFC increases as airspeed increases up to 450 mph
(d)   Both A and B are correct

64. MCS
(a)    Temp drop through turbines is greater than that of temp rise through compressor
(b)   Temp drop through turbine is same as the temp rise through same no of stages of compressor
(c)    Temp drop through turbine is about the same as that of temp rise through compressor
(d)   Temp drop through turbine is less that that of temp rise through compressor

65. TSFC is
(a)    Directly proportional to the rpm
(b)   Directly proportional to the efficiency
(c)    Inversely proportional to the efficiency
(d)   Directly proportional to the compressor ratio

66. Primary function of inlet duct is
(a)    To convert kinetic energy of rapidly moving air stream into ram pressure rise
(b)   To convert potential energy into kinetic energy inside the duct
(c)    To convert potential energy into ram pressure rise inside the duct
(d)   To convert kinetic energy into potential energy outside the duct

67.Compressor inlet screens
(a)    Are found in rotorcraft TPE and ground turbine installations
(b)   Are sued mostly in axial flow turbojet engines
(c)    A + have problems of icing and fatigue failure
(d)   B + if fitted they may be located either the inlet or the compressor inlet

68. Two shaft whose axes are at an angle to one another but in the same plane to gear used
(a)    Bevel gear
(b)   Spiral bevel gear
(c)    Spur gear
(d)   Helical gear

69. Prime requirement for stator anes is (RR31)
(a)    Corrosion resistance
(b)   Fatigue strength
(c)    Smooth surface finish
(d)   Heat resistance
 .

70. Function of P & D valve is
(a)    Flow divider
(b)   Dumping fuel after engine shut down
(c)    Fuel pressure control
(d)   All of the above

71. Propulsive efficiency of high by pass turbofan is high due to
(a)    Same length
(b)   Small turbine
(c)    Small dia
(d)   All correct

72. AME’s knows OAT is significantly shifted but TGT is same at ground. In the high power run every thing is normal then snag is
(a)    CIT system
(b)   CPP system
(c)    FCU temperature compensator
(d)   Throttle missrig

73. Trimming means
(a)    Adjustingidle & max power
(b)   Adjusting exhaust nozzle
(c)    Adjusting throttle for full forward
(d)   All of the above

75. There is a problem in the turbine then
(a)    Vibration increases with RPM increases
(b)   Vibration decreases with RPM increases
(c)    No change of vibration
(d)   None of the above

76. Ignition plug correct statement (Compare to PE)
(a)    Wider gap
(b)   Less fouling problem due to high spark
(c)    -----------------------------------------------
(d)   As 1 & 2

77. Propeller feather
(a)    Electric cut out switch
(b)   ---------------------------
(c)    ---------------------------
(d)   ---------------------------




78. Part throttle
(a)    Throttle movement less than full forward
(b)   -------------------------------------------------
(c)    -------------------------------------------------
(d)   -------------------------------------------------

79. ----------------------------------------------------
(a)    ------------------------------------------------
(b)   -----------------------------------------------
(c)    ------------------------------------------------
(d)   ------------------------------------------------
 Answers: 1- b, 2- d, 3 - a, 4 - d, 5 - a, 6 - c, 7 - b, 8 – d, 9 – d, 10 – b.
Answers: 11 – d, 12 – d, 13 – d, 14 – d, 15 – d, 16 – c, 17 – a, 18 – b, 19 – c, 20 – b,
21 – b, 22 – c, 23 – c.
Answers: 24 – c, 25 – d, 26 – a, 27 – d, 28 – c, 29 – d, 30 – b, 31 – d, 32 – d, 33 – b,
34 – a, 36 – a.
Answers: 37 – b, 38 – c, 39 – b, 40 – d, 41 – d, 42 – d, 43 – c, 44 – b, 45 – b, 46 – d,
47 – a, 48 – d, 49 – b.
Answers: 50 -  , 51 – b, 52 – a, 54, b, 55 – a, 56 -  , 57 – a, 58 – a, 59 -  , 60 – a.

Answers: 61 – d, 62 – a, 63 – d, 64 – c, 65 – c, 66 – a, 67 – c, 68 – b, 69 – b
Answers: 70 – d, 71 – a, 72 – a, 73 – a, 74 – a, 75 – a, 76 – d, 77 -  , 78 -  , 79 -  , 80