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Mechanical Engineering :: Steam Nozzles and Turbines

  1. In a 50% reaction turbine stage, tangential component of absolute velocity at rotor inlet is 537 m/s and the blade velocity is 454 m/s. The power output in kW of steam will be

  2. A.

     260 kW

    B.

     282 kW

    C.

     296 kW

    D.

     302 kW

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  3. A compound steam engine in which piston rods of high pressure and low pressure cylinders are attached to two different cranks set at 90° to each other, is called

  4. A.

     Receiver type compound engine

    B.

     Tandem type compound engine

    C.

     Woolf type compound engine

    D.

     Both (A) and (B)

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  5. A compound steam engine in which piston rods of high pressure and low pressure cylinders ' are attached to two different cranks set at 180° to each other, is called

  6. A.

     Receiver type compound engine

    B.

     Tandem type compound engine

    C.

     Woolf type compound engine

    D.

     Both (A) and (B)

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  7. The temperature of flue gases at air heater outlet should be

  8. A.

     100°C

    B.

     Above dew point temperature of flue gases

    C.

     Below dew point temperature of flue gases

    D.

     Less than wet bulb temperature of flue gases

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  9. The blade friction in the impulse turbine reduces the velocity of steam by __________ while it passes over the blades.

  10. A.

     10 to 15%

    B.

     15 to 20%

    C.

     20 to 30%

    D.

     30 to 40%

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  11. In a reaction turbine

  12. A.

     The steam is allowed to expand in the nozzle, where it gives a high velocity before it enters the moving blades

    B.

     The expansion of steam takes place partly in the fixed blades and partly in the moving blades

    C.

     The steam is expanded from a high pressure to a condenser pressure in one or more nozzles

    D.

     The pressure and temperature of steam remains constant

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  13. The isentropic enthalpy drop in moving blade is two-third of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be

  14. A.

     0.4

    B.

     0.56

    C.

     0.67

    D.

     1.67

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  15. The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam.

  16. A.

     More

    B.

     Less

    C.

     Same

    D.

     None of these

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  17. In turbines, the fluid undergoes a continuous steady flow process and the speed of flow is

  18. A.

     Low

    B.

     Very low

    C.

     High

    D.

     Very high

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  19. Expanding steam to a very low pressure (high vacuum) in steam engines is

  20. A.

     Desirable

    B.

     Economical

    C.

     Essential

    D.

     Uneconomical

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