Drag co-efficient for flow past immersed body is the ratio of _____________ to the product of velocity head and density?

Related Mcqs:

1. Cd, Cc and Cv are related (for flow through an orifice) as (where, Cd = discharge co-efficient, Cc = co-efficient of contraction = (area of jet at vena-contracta/area of opening), Cv = co-efficient of velocity = (actual velocity at vena-contracta/theoretical velocity)?

   A. Cd = Cc/Cv
   B. Cd = Cc.Cv
   C. Cd = Cv/ Cc
   D. None of these

2. As the velocity V and thus the Reynolds number of a flow past a sphere increases from very low value, the drag force for Re << 1 ?

   A. Increases linearly with V
   B. Decreases linearly with V
   C. Decreases as V2
   D. None of these

3. In which of the following body shapes, the pressure drag is large compared to the friction drag ?

   A. Stream line body
   B. Two dimensional body
   C. Bluff body
   D. None of these

4. The ratio of wall drag to total drag in the Stoke’s law range is_________________?

   A. 0.5
   B. 1
   C. 1/3
   D. 2/3

5. The ratio of the wall drag to the form drag in the Stoke’s law range (for motion of spherical particles in a stationary fluid) is__________________?

   A. 0.5
   B. 1
   C. 2
   D. 0.33

6. Co-efficient of discharge (Cd) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about__________________?

   A. 0.42
   B. 0.62
   C. 0.82
   D. 0.98

7. What is the ratio of the velocity at the axis of the pipe to the mean velocity of flow in case of pipe flow under viscous condition ?

   A. 0.5
   B. 0.67
   C. 1
   D. 2

8. The net positive suction head (NPSH) of a centrifugal pump is defined as the sum of the velocity head and the pressure head at the_________________?

   A. Discharge
   B. Suction
   C. Suction minus vapor pressure of the liquid at suction temperature
   D. Discharge minus vapor pressure of the liquid at the discharge temperature

9. Drag is the force component exerted on an immersed object, ?

   A. Passing the centroid of the body at 60°to the direction of motion
   B. The component being parallel to the flow direction
   C. The component being normal to the flow direction
   D. None of these

10. Deformation drag, which is caused by widespread deformation of fluid around the immersed body____________________?

    A. Occurs when NRe is very small
    B. Is primarily a friction drag
    C. Is independent of body length
    D. Depends mainly on cross-sectional shape