Boundary layer separation is caused by 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. 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

6. Boundary layer separation occurs when the____________________?

   A. Pressure reaches a minimum
   B. Cross-section of the channel is reduced
   C. Valve is closed in a pipeline
   D. Velocity of sound is reached

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. Existence of boundary layer in fluid flow is because of the_________________?

   A. Surface tension
   B. Fluid density
   C. Fluid viscosity
   D. Gravity forces

10. Which law is followed by the velocity distribution in the turbulent boundary layer ?

    A. Parabolic law
    B. Linear law
    C. Logarithmic law
    D. None of these