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Mechanical Engineering :: Steam Boilers and Engines

  1. A device used to heat feed water by utilising the heat in me exhaust flue gases before leaving through the chimny, is known as

  2. A.

    economiser

    B.

    fusible plug

    C.

    superheater

    D.

    stop valve


  3. The factor of evaporation for all boilers is always

  4. A.

    equal to unity

    B.

    less than unity

    C.

    greater than unity


  5. The ratio of the actual vacuum to the ideal vacuum in a condenser is called

  6. A.

    condenser efficiency

    B.

    vacuum efficiency

    C.

    nozzle efficiency

    D.

    boiler efficiency


  7. The draught (in mm of water), for maximum discharge of flue gases through the chimney, is given by (where H = Height ot the chimney in metres, and T1 = Absolute temperature of air outside the chimney in K)

  8. A.

    \(\frac{T_1}{88.25 H}\)

    B.

    \(\frac{88.25 H}{T_1}\)

    C.

    \(\frac{T_1}{176.5 H}\)

    D.

    \(\frac{176.5 H}{T_1}\)


  9. An air preheater

  10. A.

    increases evaporative capacity of the boiler

    B.

    increases the efficiency of the boiler

    C.

    enables low grade fuel to be burnt

    D.

    all of the above