With the same cross-sectional area and immersed in same turbulent flow, the largest total drag will be on__________________?

Related Mcqs:

1. In which of the following the friction drag is generally larger than pressure drag?

   A. a circular disc or plate held normal to flow
   B. a sphere
   C. a cylinder
   D. an airfoil

2. If the velocity is zero over half of the cross-sectional area and is uniform over the remaining half, then the momentum correction factor is_______________?

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

3. The eddy viscosity for turbulent flow is______________?

   A. a function of temperature only
   B. a physical property of the fluid.
   C. dependent on the flow
   D. independent of the 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. 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. 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

7. If velocity is zero over l/3rd of a cross-section and is uniform over remaining 2/3rd of the cross-section, then the correction factor for kinetic energy is__________________?

   A. 4/3
   B. 3/2
   C. 9/4
   D. 27/8

8. If a sphere of diameter 1 cm falls in castor oil of kinematic viscosity 10 stokes, with a terminal velocity of 1.5 cm/sec, the coefficient of drag on the sphere is________________?

   A. less than 1
   B. between 1 and 100
   C. 160
   D. 200

9. Drag force is a function of________________?

   1. projected area of the body
   2. mass density of the fluid
   3. velocity of the body
   The correct answer is ?

   A. (1) and (2)
   B. (1) and (3)
   C. (2) and (3)
   D. (1), (2) and (3)

10. If the weight of a body immersed in a fluid exceeds the buoyant force, then the body will________________?

    A. rise until its weight equals the buoyant force
    B. tend to move downward and it may finally sink
    C. float
    D. none of the above