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Mechanical Engineering :: Compressors, Gas Turbines and Jet Engines

  1. The following property is most important for material used for gas turbine blade

  2. A.

     Toughness

    B.

     Fatigue

    C.

     Creep

    D.

     Corrosion resistance


  3. The main purpose of reheating in gas turbine is to

  4. A.

     Increase temperature

    B.

     Reduce turbine size

    C.

     Increase power output

    D.

     Increase speed


  5. In the cross compounding of the gas turbine plant

  6. A.

     H.P. compressor is connected to H.P. turbine and L.P. compressor to L.P. turbine

    B.

     H.P. compressor is connected to L.P. turbine and L.P. compressor is connected to H.P. turbine

    C.

     Both the arrangements can be employed

    D.

     All are connected in series


  7. The advantage of multistage compression over single stage compression is

  8. A.

     Lower power consumption per unit of air delivered

    B.

     Higher volumetric efficiency

    C.

     Decreased discharge temperature

    D.

     All of the above


  9. 1 m of air at atmospheric condition weighs approximately

  10. A.

     0.5 kg

    B.

     1.0 kg

    C.

     1.3 kg

    D.

     2.2 kg


  11. A simple turbojet engine is basically

  12. A.

     A propeller system

    B.

     Gas turbine engine equipped with a propulsive nozzle and diffuse

    C.

     Chemical rocket engine

    D.

     Ramjet engine


  13. The efficiency of a jet engine is higher at

  14. A.

     Low speeds

    B.

     High speeds

    C.

     Low altitudes

    D.

     High altitudes


  15. The degree of reaction in an axial flow compressor is defined as the ratio of static enthalpy rise in the

  16. A.

     Rotor to static enthalpy rise in the stator

    B.

     Stator to static enthalpy rise in the rotor

    C.

     Rotor to static enthalpy rise in the stage

    D.

     Stator to static enthalpy rise in the stage


  17. The performance of air compressor at high altitudes will be ________ as compared to that at sea level.

  18. A.

     Same

    B.

     Lower

    C.

     Higher

    D.

     None of these


  19. Maximum work is done in compressing air when the compression is

  20. A.

     Isothermal

    B.

     Adiabatic

    C.

     Polytropic

    D.

     None of the above