1. At a constant speed of the centrifugal pump . it __________ the impeller diameter.
Capacity varies directly with
Head varies as the square of
Horsepower varies as the cube of
All of the above
✅ The correct answer is option D.
Fluid Mechanics MCQs
2. Quicksand is an example of a __________ fluid.
Bingham plastic
Dilatent
Newtonion
Pseudoplastic
✅ The correct answer is option B.
3. Pumping of a corrosive liquid is generally preferred to be done by a __________ pump, as it can be made of a variety of materials including plastics.
Piston
Gear
Positive displacement
Sump
✅ The correct answer is option B.
4. A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke’s law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity
Same as that of A
One fourth as that of A
Twice as that of A
Four times as that of A
✅ The correct answer is option B.
5. At low Reynolds number
Viscous forces are unimportant
Viscous forces control
Viscous forces control and inertial forces are unimportant
Gravity forces control
✅ The correct answer is option C.
6. __________ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500 kgf/cm².
Centrifugal
Piston
Plunger
Vane
✅ The correct answer is option C.
7. Vane anemometer
Is an area meter
Is a variable head meter
Rotates an element at a speed determined by the velocity of the fluid in which the meter is immersed
None of these
✅ The correct answer is option C.
8. Medium viscosity lubricating oil can be most ideally pumped by a __________ pump.
Vane
Piston
Centrifugal
Plunger
✅ The correct answer is option A.
9. Boundary layer thickness in turbulent flow over a flat plate increases as(where, d = distance from the leading edge.)
√d
d2/3
d4/5
d1/3
✅ The correct answer is option C.
10. With increase in the temperature, viscosity of a liquid
Increases
Decreases
Remains constant
May increase or decrease; depends on the liquid
✅ The correct answer is option B.