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Mechanical Engineering :: Hydraulic Machines

  1. Manometric head is the actual head of water against which a centrifugal pump has to work.

  2. A.
    Correct
    B.
    Incorrect

  3. The hydraulic efficiency of an impulse turbine is the

  4. A.
    ratio of the actual power produced by the turbine to the energy actually supplied by the turbine
    B.
    ratio of the actual work available at the turbine to the energy imparted to the wheel
    C.
    ratio of the work done on the wheel to the energy of the jet
    D.
    none of the above

  5. The overall efficiency for a Pelton wheel lies between

  6. A.
    0.50 to 0.65
    B.
    0.65 to 0.75
    C.
    0.75 to 0.85
    D.
    0.85 to 0.90

  7. Which of the following statement is wrong ?

  8. A.
    The reaction turbines are used for low head and high discharge.
    B.
    The angle of taper on draft tube is less than 8°.
    C.
    An impulse turbine is generally fitted slightly above the tail race.
    D.
    A Francis turbine is an impulse turbine.

  9. Which of the following statement is correct as regard to water wheels?

  10. A.
    They have slow speeds.
    B.
    They are suitable even for low water heads.
    C.
    They give constant efficiency, even if the discharge is not constant
    D.
    all of the above

  11. The efficiency of a hydraulic press is given by (where W = Weight lifted by ram, P = Force applied on plunger, A = Area of ram, and a = Area of plunger)


  12. Braking jet in an impulse turbine is used

  13. A.
    to break the jet of water
    B.
    to bring the runner to rest in a short time
    C.
    to change the direction of runner
    D.
    none of these

  14. The water in a jet propelled boat is drawn through the openings facing the direction of motion of the boat. The efficiency of propulsion is given by


  15. Head developed by a centrifugal pump is

  16. A.
    proportional to diameter of impeller
    B.
    proportional to speed of impeller
    C.
    proportional to diameter and speed of impeller
    D.
    none of the above

  17. The ratio of the normal force of jet of water on a plate inclined at an angle of 30° as compared to that when the plate is normal to jet, is

  18. A.
    1/2
    B.
    1/2
    C.
    1
    D.
    2