If x is the distance from leading edge, then the boundary layer thickness in laminar flow varies as________________?

Related Mcqs:

1. The boundary layer thickness at a distance of l m from the leading edge of a flat plate, kept at zero angle of incidence to the flow direction, is O.l cm. The velocity outside the boundary layer is 25 ml sec. The boundary layer thickness at a distance of 4 m is__________________?

   A. 0.40 cm
   B. 0.20 cm
   C. 0.10 cm
   D. 0.05 cm

   Assume that boundary layer is entirely laminar

2. The boundary layer thickness in turbulent flow varies as______________?

   A. x”7
   B. x,/2
   C. x4/5
   D. x3/5

   where x is the distance from leading edge

3. The maximum thickness of boundary layer in a pipe of radius r is____________________?

   A. 0
   B. r/2
   C. r
   D. 2r

4. The correct relationship among displacement thickness d, momentum thickness m and energy thickness e is_________________?

   A. d > m > e
   B. d > e > m
   C. e > m > d
   D. e > d > m

5. The distance y from pipe boundary, at which the point velocity is equal to average velocity for turbulent flow, is________________?

   A. 0.223 R
   B. 0.423 R
   C. 0.577 R
   D. 0.707 R

   where R is radius of pipe

6. The depth ‘d’ below the free surface at which the point velocity is equal to the average velocity of flow for a uniform laminar flow with a free surface, will be_________________?

   A. 0.423 D
   B. 0.577 D
   C. 0.223 D
   D. 0.707 D

   where D is the depth of flow

7. The distance from pipe boundary, at which the turbulent shear stress is one-third die wall shear stress, is_______________?

   A. 1/3 R
   B. 1/2 R
   C. 2/3 R
   D. 3/4R

   where R is the radius of pipe

8. A fluid of kinematic viscosity 0.4 cm2/sec flows through a 8 cm diameter pipe. The maximum velocity for laminar flow will be__________________?

   A. less than 1 m/sec
   B. 1 m/sec
   C. 1.5 m/sec
   D. 2 m/sec

9. For laminar flow in circular pipes, the Darcy’s friction factor f is equal to_________________?

   A. 16/Re
   B. 32/ Re
   C. 64/ Re
   D. none of the above where R,, is Reynolds number

10. The velocity distribution for laminar flow through a circular tube__________________?

    A. is constant over the cross-section
    B. varies linearly from zero at walls to maximum at centre
    C. varies parabolically with maximum at the centre
    D. none of the above