What is the value of Fanning friction factor f ‘ for smooth pipe at NRe = 106 approximately ?

Related Mcqs:

1. Friction factor for a hydraulically smooth pipe at NRe = 2100 is f1. If the pipe is further smoothened (i.e., roughness is reduced), the friction factor at the same value of NRe, will_______________?

   A. Increase
   B. Decrease
   C. Remain unchanged
   D. Increase or decrease depending on the pipe material

2. A centrifugal pump is used to pump water through a horizontal distance of 150 m, and then raised to an overhead tank 10 m above. The pipe is smooth with an I.D of 50 mm. What head (m of water) must the pump generate at its exit E. to deliver water at a flow rate of 0.001 m3/s? The Fanning friction factor, f is 0.0062 ?

   A. 10 m
   B. 11 m
   C. 11.8 m
   D. 30 m

3. Fanning friction factor is equal to (where, fB = Blasius friction factor) ?

   A. fB/4
   B. fB/2
   C. 4fB
   D. 2fB

4. If Blasius or Darcy friction factor is ‘f1’ then the Fanning friction factor is equal to____________________?

   A. f1/4
   B. 4f2
   C. 2f1
   D. f1/2

5. Consider two pipes of same length and diameter through which water is passed at the same velocity. The friction factor for rough pipe is f1 and that for smooth pipe is f2. Pick out the correct statement ?

   A. f1 = f2
   B. f1 < f2
   C. f1 > f2
   D. Data not sufficient to relate f1 & f2

6. Fanning friction factor for laminar flow of fluid in a circular pipe is____________________?

   A. Not a function of the roughness of pipe wall
   B. Inversely proportional to Reynolds number
   C. Both A. & B.
   D. Neither A. nor B.

7. For turbulent flow in smooth circular pipe, the velocity distribution is a function of the distance ‘d’ measured from the wall of the pipe and the friction velocity ‘v’, and it follows a _____________ relationship?

   A. Logarithmic
   B. Linear
   C. Hyperbolic
   D. Parabolic

8. Colebrook equation for friction factor in turbulent flow is given by, f-0.5 = -4 loge [(ε/D) + (1.26/NRe √F). It reduces to Nikuradse equation for a value of (ϵ/D) equal to __________________?

   A. 0
   B. 1
   C. ∞
   D. 0.5

9. For a given Reynolds number, in a hydraulically smooth pipe, further smoothening ____________ the friction factor?

   A. Brings about no further reduction of
   B. Increases
   C. Decreases
   D. None of these

10. In turbulent flow, a rough pipe has the same friction factor as a smooth pipe____________________?

    A. In the zone of complete turbulence
    B. When the roughness projections are much smaller than the thickness of the laminar film
    C. Everywhere in the transition zone
    D. When the friction factor is independent of the Reynold’s number