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Mechanical Engineering :: Hydraulics and Fluid Mechanics

  1. In a short cylindrical external mouthpiece, the vena contracta occurs at a distance __________ the diameter of the orifice from the outlet of orifice.

  2. A.

     Equal to

    B.

     One-fourth

    C.

     One-third

    D.

     One-half


  3. The total pressure on the top of a closed cylindrical vessel of radius (r) completely filled up with liquid of specific weight (w) and rotating at (ω) rad/s about its vertical axis, is

  4. A.

     π w ω² r²/4g

    B.

     π w ω² r³/4g

    C.

     π w ω² r⁴/4g

    D.

     π w ω² r²/2g


  5. Which of the following instrument can be used for measuring speed of a submarine moving in deep sea?

  6. A.

     Venturimeter

    B.

     Orifice plate

    C.

     Hot wire anemometer

    D.

     Pitot tube


  7. A pressure of 25 m of head of water is equal to

  8. A.

     25 kN/ m²

    B.

     245 kN/ m²

    C.

     2500 kN/m²

    D.

     2.5 kN/ m²


  9. In a centrifugal pump casing, the flow of water leaving the

  10. A.

     Radial

    B.

     Axial

    C.

     Centrifugal

    D.

     Vortex


  11. According to fan laws, for the fans having constant wheel diameters, the power demand varies

  12. A.

     Directly as fan speed

    B.

     Square of fan speed

    C.

     Cube of fan speed

    D.

     Square root of fan speed


  13. The number of buckets on the periphery of a Pelton wheel is given by

  14. A.

     (D/2d) + 5

    B.

     (D/2d) + 10

    C.

     (D/2d) + 15

    D.

     (D/2d) + 20


  15. The pressure at a point in a fluid will not be same in all the directions when the fluid is

  16. A.

     Moving

    B.

     Viscous

    C.

     Viscous and static

    D.

     Viscous and moving


  17. When a body is placed over a liquid, it will sink down if

  18. A.

     Gravitational force is equal to the up-thrust of the liquid

    B.

     Gravitational force is less than the up-thrust of the liquid

    C.

     Gravitational force is more than the up-thrust of the liquid

    D.

     None of the above


  19. The kinematic viscosity of an oil (in stokes) whose specific gravity is 0.95 and viscosity 0.011 poise, is

  20. A.

     0.0116 stoke

    B.

     0.116 stoke

    C.

     0.0611 stoke

    D.

     0.611 stoke