Design of the casing of centrifugal pump should be such as to minimise the________________?

Related Mcqs:

1. 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

2. A centrifugal pump used to pump water is used to pump an oil with specific gravity of 0.8 at the same rate. The power consumption will now_________________?

   A. Increase
   B. Decrease
   C. Remain same
   D. Data insufficient to predict

3. A centrifugal pump designed to pump water is employed to pump a more viscous oil. In the later case, the pump_________________?

   A. Develops a lower head
   B. Capacity is reduced
   C. Requires more power
   D. All A., B. and C.

4. Volute type of casing is provided in a centrifugal pump to___________________?

   A. Convert velocity head to pressure head
   B. Convert pressure head to velocity head
   C. Reduce the discharge fluctuation
   D. Increase the discharge

5. Volute of a centrifugal pump should be designed in a fashion, such that the________________?

   A. Kinetic head gets converted into static head
   B. Moving stream gradually reduces velocity
   C. Mean velocity remains constant
   D. None of these

6. Centrifugal pump is normally classified on the basis of the________________?

   A. rpm
   B. Type of casing
   C. Impeller blade angle
   D. Number of blades in impeller

7. Centrifugal pump can’t be used to pump _____________________?

   A. Molten sodium (used as a coolant in Fast Breeder Reactor)
   B. Moderately viscous vegetable oil used in soap industry
   C. Thick molten soap at 80°C
   D. None of the above

8. Higher specific speed (200-500) of a centrifugal pump indicates that the pump is of ______________ flow type?

   A. Axial
   B. Radial
   C. Mixed
   D. None of these

9. Which is the correct relationship for a centrifugal pump? (Where, D = Impeller diameter, inches H = Head developed, ft of liquid pumped N = Speed of pump, rpm) ?

   A. D = 1840 H0.5/N
   B. D = 1840 N/H0.5
   C. H = 1840 D0.5/N
   D. D = 1840 H/N

10. Consider a centrifugal pump having a specific impeller diameter, fixed impeller speed pumping a liquid of constant density at a particular discharge capacity. With decrease in the capacity of the pump, the _______________ decreases?

    A. NPSH required
    B. BHP required by the pump
    C. Head of the liquid pumped
    D. All A., B. and C.