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

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. Multiple blade paddle agitator is used for mixing high viscosity liquids/paste in which the paddle diameter is commonly 0.8 times the tank diameter. However, the width of the blade is in the range of ______________ times the paddle diameter?

   A. 0.1 to 0.25
   B. 0.3 to 0.5
   C. 0.5 to 0.6
   D. 0.65 to 0.80

3. In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones; because the smaller diameter tubes ______________?

   A. Are easier to clean
   B. Are less prone to fouling
   C. Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less
   D. None of these

4. 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

5. 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

6. Practical dividing line between a ductile and brittle materials is suggested, when the ultimate elongation is about 5%. Generally, larger the knuckle radius, stronger is the corner torus section of a head. The knuckle radius provided should be less than ______________ of the head?

   A. 6% of I.D.
   B. 3 times the thickness
   C. Either A. or B., whichever is larger
   D. Either A. or B., whichever is smaller

7. Bubble cap diameter used for the distillation column having diameter ranging from 1.5 to 4.5 metres is about ______________ mm?

   A. 10
   B. 50
   C. 100
   D. 200

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. Nominal size of a pipe is an indication of its _______________ diameter?

   A. Inner
   B. Outer
   C. Approximate
   D. None of these

10. Pressure drop due to pipe fittings can be estimated by the equation, ΔP/ρ = 4f, (Le/D) (V2/2gc) where, Le = equivalent length of straight pipeline which will incur the same frictional loss as the fitting and D = diameter of the fitting. The value of (Le/D) (dimensionless) for 45° elbow and 180° close return bends would be respectively around______________________?

    A. 5 and 10
    B. 45 and 75
    C. 180 and 300
    D. 300 and 500