The boundary layer thickness at a given section along a flat plate _____________ with increasing Reynold’s number?

Related Mcqs:

1. In the laminar boundary layer flow over a flat plate, the ratio (δ/x) varies as: (where, ‘δ’ is the boundary layer thickness and ‘x’ is the distance from the leading edge in the direction of flow)?

   A. Re
   B. √Re
   C. 1/Re
   D. Re-1/2

2. For flow past a flat plate, if „x‟ is the distance along the plate in the direction of flow, the boundary layer thickness is proportional to________________?

   A. √x
   B. 1/√x
   C. x
   D. 1/x

3. What is the ratio of displacement thickness to nominal thickness for a linear distribution of velocity in the boundary layer on a flat plate ?

   A. 0.5
   B. 1
   C. 1.5
   D. 2

4. Boundary layer thickness in laminar flow over a flat plate increases as(where, d = distance from the leading edge.) ?

   A. √d
   B. d1/3
   C. d2
   D. d2/3

5. Boundary layer thickness in turbulent flow over a flat plate increases as(where, d = distance from the leading edge.) ?

   A. √d
   B. d2/3
   C. d4/5
   D. d1/3

6. The ratio of hydrodynamic boundary layer to thermal boundary layer thickness in case of liquid metals is__________________?

   A. < 1
   B. 1
   C. > 1
   D. 2

7. Which of the following must be followed by the flow of a fluid (real or ideal)? (I) Newton’s law of viscosity. (II) Newton’s second law of motion. (III) The continuity equation. (IV) Velocity of boundary layer must be zero relative to boundary. (V) Fluid cannot penetrate a boundary?

   A. I, II, III
   B. II, III, V
   C. I, II, V
   D. II, IV, V

8. Boundary layer separation is characterised by one of the conditions given below, where ‘Re’ is the Reynolds number for the flow. Select the appropriate conditions ?

   A. Re <> 1, accelerating flow
   C. Re << 1, decelerating flow
   D. Re >>1, decelerating flow

9. A Bingham fluid of viscosity μ = 10 Pa.s and yield stress, η0 = 10 KPa, is shared between flat parallel plates separated by a distance of 10-3 m. The top plate is moving with a velocity of 1 m/s. The shear stress on the plate is________________?

   A. 10 KPa
   B. 20 KPa
   C. 30 KPa
   D. 40 KPa

10. The effect of solid boundary on the fluid flow is confined to the boundary layer, except for fluids ?

    A. Having high viscosities
    B. Moving at low velocities
    C. Both A. & B.
    D. Neither A. nor B.