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

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 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

3. 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

4. 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

5. For hydro-dynamically smooth boundary, the friction coefficient for turbulent flow is_______________?

   A. constant
   B. dependent only on Reynolds number
   C. a function of Reynolds number and relative roughness
   D. dependent on relative roughness only

6. In a two dimensional incompressible steady flow around an airfoil, the stream lines are 2 cm apart at a great distance from the airfoil, where the velocity is 30 m/sec. The velocity near the airfoil, where the stream lines are 1.5 cm apart, is_________________?

   A. 22.5 m/sec
   B. 33 m/sec
   C. 40 m/sec
   D. 90 m/sec

7. The ratio of average velocity to maximum velocity for steady laminar flow in circular pipes is_______________?

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

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

   A. x
   B. x
   C. x
   D. x/7

9. 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

10. Flow at constant rate through a tapering pipe is________________?

    1. steady flow
    2. uniform flow
    3. unsteady flow
    4. non-uniform flow
    The correct answer is?

    A. (1) and (2)
    B. (1)and(iv)
    C. (2) and (3)
    D. (2) and (4)