The excess of the sum of pressure & velocity heads over the vapor pressure of the liquid at the suction is called the___________________?

Related Mcqs:

1. In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure ______________ the vapor pressure of the liquid at the suction temperature?

   A. Lower than
   B. Higher than
   C. Equal to
   D. None of these

2. The location of centre of pressure, which defines the point of application of the total pressure force on the surface, can be calculated by applying the principle of moments according to which “sum of the moment of the resultant force about an axis is equal to the sum of the components about the same axis”. The centre of pressure of a rectangular surface (of width ‘w’) immersed vertically in a static mass of fluid is at a depth of (where, y = depth of the liquid) ?

   A. 1/(y/3)
   B. 2y/3
   C. 1/(y/4)
   D. 3y/4

3. The net positive suction head (NPSH) of a centrifugal pump is defined as the sum of the velocity head and the pressure head at the_________________?

   A. Discharge
   B. Suction
   C. Suction minus vapor pressure of the liquid at suction temperature
   D. Discharge minus vapor pressure of the liquid at the discharge temperature

4. A compressor that takes suction at a pressure below atmospheric and discharge against atmospheric pressure is called a ____________ pump?

   A. Sump
   B. Volute
   C. Vacuum
   D. Submerged

5. For a fluid rotating at constant angular velocity about vertical axis as a rigid body, the pressure intensity varies as the___________________?

   A. Square of the radial distance
   B. Radial distance linearly
   C. Inverse of the radial distance
   D. Elevation along vertical direction

6. Umf is the minimum fluidisation velocity for a bed of particles. An increase in the superficial gas velocity from 2 Umf to 2.5 Umf results in (all velocities are smaller than the entrainment velocity of the particles) no change in the_______________?

   A. Drag on particles
   B. Drag on column walls
   C. Bed height
   D. Bed voidage

7. Cd, Cc and Cv are related (for flow through an orifice) as (where, Cd = discharge co-efficient, Cc = co-efficient of contraction = (area of jet at vena-contracta/area of opening), Cv = co-efficient of velocity = (actual velocity at vena-contracta/theoretical velocity)?

   A. Cd = Cc/Cv
   B. Cd = Cc.Cv
   C. Cd = Cv/ Cc
   D. None of these

8. Cavitation occurs in a centrifugal pump when the suction pressure is________________?

   A. Less than the vapour pressure of the liquid at that temperature
   B. Greater than the vapour pressure of the liquid at that temperature
   C. Equal to the vapour pressure
   D. Equal to the developed head

9. For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is________________?

   A. More
   B. Less
   C. Equal
   D. Independent of porosity

10. Piezometric head is the sum of the ______________ heads?

    A. Elevation & kinetic energy
    B. Elevation & pressure
    C. Kinetic energy & pressure
    D. None of these