Friction factor for turbulent flow in a new pipe is given by____________________?

Related Mcqs:

1. For turbulent flow (NRe > 2100) of low viscosity fluid (μ > 20cp) in steel pipes, the optimum inside pipe diameter is given by(where, Q = fluid flow rate, ft3/sec, ρ = fluid density, lb/ft3 μ = fluid viscosity, centipoise Di = optimum inside pipe diameter, inches) ?

   A. Di, opt = 3.9 Q0.45 ρ0.13
   B. Di, opt = 3.9 Q0.45. μ0.95
   C. Di, opt = 4.7 Q0.36. μ3.2ρ0.13
   D. Di, opt = 3 Q0.36. μ0.88

2. For laminar flow (NRe < 2100) in steel pipe, the optimum inside pipe diameter is given by____________________?

   A. Di, opt = 3 Q0.36 ρ0.18
   B. Di, opt = 3.9 Q0.45 ρ0.23
   C. Di, opt = 7.6 Q0.36 ρ0.9
   D. Di, opt = 3 Q0.36 ρ1.86 μ0.08

3. To keep the power input constant for a stirred vessel operating under fully developed turbulent flow conditions (constant power number), if the impeller diameter is increased by 20%, the impeller speed should be decreased by a factor of_________________?

   A. (1.2)3/2
   B. (1.2)3/5
   C. (1.2)2/3
   D. (1.2)5/3

4. Tube side pressure drop in a 1-2 heat exchanger (for turbulent flow of fluids through the tubes) is about __________ times, that in a 1-1 heat exchanger having the same size & number of tubes and operated at the same liquid flow rate ?

   A. 2
   B. ½
   C. 4
   D. 8

5. Factor of safety (i.e., overdesign factor) in heat transfer equipments is about _____________ percent more than the actual/theoretical design factor?

   A. 5-10
   B. 15-20
   C. 30-35
   D. 35-40

6. Tube side heat transfer co-efficient for turbulent flow of liquid through tubes is proportional to___________________?

   A. G0.2
   B. G0.5
   C. G0.8
   D. G1.5

7. For pipe flows, head is proportional to ______________ at constant capacity (where D = pipe diameter) ?

   A. 1/D
   B. 1/D2
   C. 1/D5
   D. D2

8. Wall thickness of schedule 40 pipe as compared to that of schedule 80 pipe is ___________________?

   A. More
   B. Less
   C. Same
   D. Either A. or B.; depends upon the I.D. of the pipe

9. Optimum economic pipe diameter for fluid flow is determined by the____________________?

   A. Viscosity of the fluid
   B. Density of the fluid
   C. Total cost considerations (pumping cost plus fixed cost of the pipe)
   D. None of these

10. For a given fluid, as the pipe diameter increases, the pumping cost ____________________?

    A. Decreases
    B. Increases
    C. Remain unaffected
    D. May increase or decrease depending upon whether the fluid is Newtonian or non-Newtonian