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Mechanical Engineering :: Steam Nozzles and Turbines

  1. The stage efficiency (ηS) is given by (where ηB = Blading efficiency, and ηN = Nozzle efficiency)

  2. A.

     ηS = ηB × ηN

    B.

     ηS = ηB / ηN

    C.

     ηS = ηN / ηB

    D.

     None of these


  3. The dry saturated steam at very low pressure, (510 kg/cm²) when throttled to atmosphere will become

  4. A.

     Wet

    B.

     Superheated

    C.

     Remain dry saturated

    D.

     Dry


  5. The dry saturated steam at very high pressure (150200 kg/cm²) when throttled to atmosphere will become

  6. A.

     Wet

    B.

     Superheated

    C.

     Remain dry saturated

    D.

     Dry


  7. Reheating of steam under ideal conditions takes place at constant

  8. A.

     Entropy

    B.

     Enthalpy

    C.

     Pressure

    D.

     Temperature


  9. A binary vapor plant consists of

  10. A.

     Steam turbine

    B.

     Steam condenser

    C.

     Mercury boiler

    D.

     All of these


  11. Feed water conditioning in thermal power plants in done to

  12. A.

     Reduce hardness and for removal of solids

    B.

     Increase efficiency of thermal power plant

    C.

     Increase heat transfer rate

    D.

     Increase steam parameters


  13. The density of supersaturated steam is about __________ that of the ordinary saturated vapor at the corresponding pressure.

  14. A.

     Same as

    B.

     2 times

    C.

     4 times

    D.

     8 times


  15. A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is known as

  16. A.

     Superheater

    B.

     Air-preheater

    C.

     Economizer

    D.

     Injector


  17. The ratio of brake power to the indicated power is known as

  18. A.

     Mechanical efficiency

    B.

     Overall efficiency

    C.

     Indicated thermal efficiency

    D.

     Brake thermal efficiency


  19. The ratio of the isentropic heat drop to the heat supplied, is called

  20. A.

     Reheat factor

    B.

     Stage efficiency

    C.

     Internal efficiency

    D.

     Rankine efficiency