Laminar flow of a Newtonian fluid ceases to exist, when the Reynolds number exceeds___________________?

Related Mcqs:

1. Bernoulli’s equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoulli’s equation? A. Fluid flow is frictionless & irrotational. B. Fluid flow is steady. C. Fluid flow is uniform & turbulent. D. Fluid is compressible. E. Fluid is incompressible ?

   A. A, C, D
   B. B, D, E
   C. A, B, E
   D. A, D, E

2. For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) ?

   A. μ
   B. 1/μ
   C. √μ
   D. 1/√μ

3. The ratio of average fluid velocity to the maximum velocity in case of laminar flow of a Newtonian fluid in a circular pipe is_____________________?

   A. 0.5
   B. 1
   C. 2
   D. 0.66

4. For laminar flow of Newtonian fluid in a circular pipe, the velocity distribution is a function of the distance ‘d’ measured from the centre line of the pipe, and it follows a ______________ relationship?

   A. Logarithmic
   B. Parabolic
   C. Hyperbolic
   D. Linear

5. For turbulent flow of Newtonian fluid in a circular cross-section pipe, the ratio of maximum to average fluid velocity is ________________?

   A. 0.5
   B. 1
   C. 0.66
   D. < 0.5

6. In case of turbulent flow of a Newtonian fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity)?

   A. Vavg
   B. 1.2 Vavg
   C. 1.5 Vavg
   D. 1.8 Vavg

7. What is the shear rate at the pipe wall, in case of laminar flow of Newtonian fluids in a pipe of diameter ‘D’ & length ‘L’ incurring a pressure drop ‘Δp’ with average velocity ‘Vavg’ ?

   A. D Δp/8L
   B. D Δp/4L
   C. 8 Vavg/D
   D. 4 Vavg/D

8. The velocity profile exhibited by laminar flow of Newtonian fluids is such that the velocity distribution w.r.t. radius of the circular pipe is a/an ______________ with the apex at the centre line of the pipe?

   A. Hyperbola
   B. Parabola
   C. Semi-circle
   D. Semi-ellipse

9. A Newtonian liquid (ρ = density, μ = viscosity) is flowing with velocity „v‟ in a tube of diameter ‘D’. Let Δp be the pressure drop across the length ‘L’. For a laminar flow, Δp is proportional to_________________?

   A. Lρv2/D
   B. LμV/D2
   C. Dρv2/L
   D. μV/L

10. In which type of fluid flow, the velocity of flow of fluid changes from point to point in the fluid at any instant ?

    A. Rotational
    B. Unsteady
    C. Turbulent
    D. Non-uniform