721. Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m³, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is
90
60
45
30
✅ The correct answer is option B.
Fluid Mechanics MCQs
722. In fluid flow, the boundary layer separation can not occur
In case of boundaries experiencing form drag
At points of abrupt changes in the flow directions
In laminar flow
None of these
✅ The correct answer is option D.
723. 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
Discharge
Suction
Suction minus vapor pressure of the liquid at suction temperature
Discharge minus vapor pressure of the liquid at the discharge temperature
✅ The correct answer is option C.
724. In magnetic flow meters, voltage generation is
Due to the motion of conducting fluid through an externally generated uniform field
Proportional to the fluid velocity
Both A and B
Neither A nor B
✅ The correct answer is option C.
725. A mixed flow centrifugal pump
Employs such an impeller, through which the flow is a combination of radial & axial flow
Mixes the two fluids before pumping them
Pumps the two fluids separately and then mixes them
Employs impellers in both the radial & axial directions
✅ The correct answer is option A.
726. The specific speed of a pump is defined as the speed of a unit of such a size, that it
Delivers unit discharge at unit head
Requires unit power for unit head
Delivers unit discharge at unit power
None of these
✅ The correct answer is option A.
727. In case of coutte flow, the fluid flow is between two large flat parallel plates with
Top plate moving and the bottom plate fixed
Bottom plate moving and the top plate fixed
Both the plates fixed
Both the plates moving
✅ The correct answer is option A.