Fluid Mechanics

541.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

1. Discharge
2. Suction
3. Suction minus vapor pressure of the liquid at suction temperature
4. Discharge minus vapor pressure of the liquid at the discharge temperature

View answer

542.The nominal size of a hose pipe is specified by its

1. I.D.
2. O.D.
3. Thickness
4. None of these

View answer

543.The normal stress is the same in all directions at a point in a fluid, when the fluid is

1. Non-viscous
2. Incompressible
3. Both (A) and (B)
4. Having no motion of one fluid layer relative to the other

View answer

544.The percentage slip in a reciprocating pump set is given by the & of (where, Q₁ = actual discharge Q₂ = theoretical discharge).

1. Q₁/Q₂
2. Q₂/Q₁
3. (Q₂ - Q₁)/Q₁
4. (Q₂ - Q₁)/Q₂

View answer

545.The peripheral velocity at inlet of a centrifugal pump having inlet diameter of 25 cms and rotating at 950 rpm is _________ m/sec.

1. 1.8
2. 12.4
3. 186.2
4. 736.4

View answer

546.The phenomenon occuring during pumping of a liquid solution containing dissolved gases, which may come out of the solution giving rise to gas pockets, is termed as

1. Evaporation
2. Cavitation
3. Sublimation
4. Stripping

View answer

547.The pipe wall thickness is minimum for a pipe of given nominal size having schedule number

1. 160
2. 120
3. 80
4. 40

View answer

548.The pitot static tube does not measure the _________ pressure.

1. Static
2. Total
3. Difference in static & dynamic
4. All (A), (B) and (C)

View answer

549.The Prandtl mixing length is

1. Zero at the pipe wall and is a universal constant
2. Independent of radial distance from the pipe axis
3. Independent of the shear stress
4. Useful for computing laminar flow problems

View answer

550.The Prandtl Pitot tube measures the

1. Velocity at a point in the flow
2. Pressure at a point
3. Average flow velocity
4. Pressure difference in pipe flow

View answer