Cavitation in a pump creates so many undesirable effects. Out of the following, which is not an undesirable effect created by cavitation ?

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. Cavitation occurs in a centrifugal pump when the suction pressure is________________?

   A. Less than the vapour pressure of the liquid at that temperature
   B. Greater than the vapour pressure of the liquid at that temperature
   C. Equal to the vapour pressure
   D. Equal to the developed head

5. In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure ______________ the vapor pressure of the liquid at the suction temperature?

   A. Lower than
   B. Higher than
   C. Equal to
   D. None of these

6. Cavitation in a centrifugal pump can be avoided by keeping the__________________?

   A. Inlet pressure high
   B. Outlet pressure low
   C. Inlet pressure low
   D. Outlet pressure high

7. What causes cavitation in centrifugal pump ?

   A. High suction pressure
   B. Low barometric pressure
   C. Low suction pressure
   D. High suction velocity

8. 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

9. 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

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.