Home / Mechanical Engineering / Steam Nozzles and Turbines :: section-4

Mechanical Engineering :: Steam Nozzles and Turbines

  1. The critical pressure gives the velocity of steam at the throat

  2. A.

     Equal to the velocity of sound

    B.

     Less than the velocity of sound

    C.

     More than the velocity of sound

    D.

     None of these


  3. A regenerative steam cycle renders

  4. A.

     Increased work output per unit mass of steam

    B.

     Decreased work output per unit mass of steam

    C.

     Increased thermal efficiency

    D.

     Decreased work output per unit mass of steam as well as increased thermal efficiency


  5. The flow of steam is supersonic

  6. A.

     At the entrance to the nozzle

    B.

     At the throat of the nozzle

    C.

     In the convergent portion of the nozzle

    D.

     In the divergent portion of the nozzle


  7. The equivalent evaporation of a boiler is a measure to compare

  8. A.

     The given boiler with the model

    B.

     The two different boilers of the same make

    C.

     Two different makes of boilers operating under the same operating conditions

    D.

     Any type of boilers operating under any conditions


  9. Desecration of feed water is carried out because it reduces

  10. A.

     Cavitation of boiler feed pumps

    B.

     Corrosion caused by oxygen

    C.

     Heat transfer coefficient

    D.

     pH value of water


  11. The velocity of steam at throat of the nozzle is __________ the velocity of sound.

  12. A.

     Equal to

    B.

     Less than

    C.

     More than

    D.

     None of these


  13. The friction in the nozzle __________ exit velocity of steam.

  14. A.

     Has no effect on

    B.

     Decreases

    C.

     Increases

    D.

     None of these


  15. For water, at pressures below atmospheric;

  16. A.

     Melting point rises slightly and boiling point drops markedly

    B.

     Melting point rises markedly and boiling point drops markedly

    C.

     Melting point drops slightly and boiling point drops markedly

    D.

     Melting point drops slightly and boiling point drops slightly


  17. If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by

  18. A.

     Throttling calorimeter

    B.

     Separating calorimeter

    C.

     Combined separating and throttling calorimeter

    D.

     Bucket calorimeter


  19. Which of the following statement is correct?

  20. A.

     The efficiency of steam turbines is greater than steam engines

    B.

     A flywheel is a must for steam turbine

    C.

     The turbine blades do not change the direction of steam issuing from the nozzle

    D.

     The pressure of steam, in reaction turbines, is increased in fixed blades as well as in moving blades