21. As per Newton’s law of viscosity, the shear stress for a given rate of angular deformation of fluid is proportional to(where, μ = fluid viscosity)
1/μ
μ
μ²
1/μ²
✅ The correct answer is option B.
Fluid Mechanics MCQs
22. For a particle settling in water at its terminal settling velocity, which of the following is true?
Buoyancy = weight + drag
Weight = buoyancy + drag
Drag = buoyancy + weight
Drag = weight
✅ The correct answer is option B.
23. In case of turbulent flow of fluid through a circular pipe, the
Mean flow velocity is about 0.5 times the maximum velocity
Velocity profile becomes flatter and flatter with increasing Reynolds number
Point of maximum instability exists at a distance of 2r/3 from the pipe wall (r = pipe radius)
Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
✅ The correct answer is option D.
24. Enamels and paints are generally __________ fluid.
Reheopectic
Pseudo-plastic
Thixotropic
Dilatant
✅ The correct answer is option B.
25. The boundary layer is that part of a moving fluid, in which the fluid velocity is
Affected by the fluid flow pressure
Constant
Affected by the presence of a solid boundary
All of the above
✅ The correct answer is option C.
26. For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is
More
Less
Equal
Independent of porosity
✅ The correct answer is option B.
27. Velocity distribution for flow between two fixed parallel plates
Varies parabolically across the section
Is constant over the entire cross-section
Is zero at the plates and increases linearly to the midplane
None of these
✅ The correct answer is option A.
28. Fluidised beds are formed, when the
Fluid friction is zero
Gravity force is less than the fluid friction
Pressure forces equal gravity forces
Sum of the fluid friction and pressure forces is equal and opposite to gravity forces
✅ The correct answer is option B.
29. The maximum depth from which a centrifugal pump can draw water is
Dependent on the speed of the pump
Dependent on the power of the pump
34 feet
150 feet
✅ The correct answer is option C.
30. Drag co-efficient for flow past immersed body is the ratio of __________ to the product of velocity head and density.
Shear stress
Shear force
Average drag per unit projected area
None of these
✅ The correct answer is option C.