Boundary layer separation occurs when the____________________?

Related Mcqs:

1. 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

2. 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

3. 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

4. Boundary layer separation is caused by the ____________________?

   A. Reduction of pressure below vapour pressure
   B. Reduction of pressure gradient to zero
   C. Adverse pressure gradient
   D. Reduction of boundary layer thickness to zero

5. Boundary layer separation is caused by the_________________?

   A. Reduction of pressure to vapour pressure
   B. Boundary layer thickness reducing to zero
   C. Adverse pressure gradient
   D. Reduction of pressure gradient to zero

6. In fluid flow, the boundary layer separation cannot occur___________________?

   A. In case of boundaries experiencing form drag
   B. At points of abrupt changes in the flow directions
   C. In laminar flow
   D. None of these

7. 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

8. 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.

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

   A. Increases
   B. Decreases
   C. Remain same
   D. May increase or decrease

10. The boundary layer is that part of a moving fluid, in which the fluid velocity is_________________?

    A. Affected by the fluid flow pressure
    B. Constant
    C. Affected by the presence of a solid boundary
    D. All A., B. and C.