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Mechanical Engineering :: Steam Nozzles and Turbines

  1. The capacity of induced draft fan compared to forced draft fan in a boiler is

  2. A.

     Same

    B.

     More

    C.

     Less

    D.

     Less or more depending on size of boiler


  3. Which of the following statement indicates the difference between Cornish boiler and Lancashire boiler?

  4. A.

     Cornish boiler is a water tube boiler whereas Lancashire boiler is a fire tube boiler

    B.

     Cornish boiler is a fire tube boiler whereas Lancashire boiler is a water tube boiler

    C.

     Cornish boiler has one flue tube whereas Lancashire boiler has two flue tubes

    D.

     Cornish boiler has two flue tubes whereas Lancashire boiler has one flue tube


  5. The ratio of the useful heat drop to the isentropic heat drop is called

  6. A.

     Condenser efficiency

    B.

     Nozzle efficiency

    C.

     Boiler efficiency

    D.

     Vacuum efficiency


  7. In recuperative air preheaters, the heat is transferred

  8. A.

     From a metal wall from one medium to another

    B.

     From heating an intermediate material and then heating the air from this material

    C.

     By direct mixing

    D.

     Heat is transferred by bleeding some gases from furnace


  9. In regenerative air preheaters, the heat is transferred

  10. A.

     From a metal wall from one medium to another

    B.

     From heating an intermediate material and then heating the air from this material

    C.

     By direct mixing

    D.

     Heat is transferred by bleeding some gas from furnace


  11. Which of the following statement is wrong?

  12. A.

     The factor of evaporation for all boilers is always greater than unity

    B.

     The amount of water evaporated in kg per kg of fuel burnt is called equivalent evaporation from and at 100° C

    C.

     The ratio of heat actually used in producing the steam to the heat liberated in the furnace is called boiler efficiency

    D.

     None of the above


  13. Which of the following statement is wrong?

  14. A.

     The critical pressure gives the velocity of steam at the throat equal to the velocity of sound

    B.

     The flow in the convergent portion of the nozzle is subsonic

    C.

     The flow in the divergent portion of the nozzle is supersonic

    D.

     To increase the velocity of steam above sonic velocity (supersonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary


  15. Which of the following statement is wrong?

  16. A.

     Locomotive boiler is a water tube boiler

    B.

     Water tube boilers are internally fired

    C.

     Lamont boiler is a low pressure water tube boiler

    D.

     All of the above


  17. Which of the following statement is wrong?

  18. A.

     The mechanical draught reduces the height of chimney

    B.

     The natural draught reduces the fuel consumption

    C.

     A balanced draught is a combination of induced and forced draught

    D.

     All of the above


  19. An air preheater is installed

  20. A.

     Before the economiser

    B.

     Before the superheater

    C.

     Between the economiser and chimney

    D.

     None of these