Maximum theoretical suction lift for water at 15°C by a centrifugal pump is 34 ft. The same for water at 90°C will be _____________________ ft?

Related Mcqs:

1. What is the maximum theoretical suction lift (metres) of a reciprocating pump ?

   A. 5
   B. 10
   C. 50
   D. 100

2. 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

3. Actual lift of a pump is always less than the theoretical lift and is limited by the__________________________?

   A. Specific gravity & temperature of the liquid
   B. Leakage & pressure decreasing at higher elevations
   C. Frictional resistance through pipes, fittings & passages
   D. All A., B. and C.

4. 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

5. 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

6. 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.

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. Foot valves are provided in the suction line of a centrifugal pump to ____________________?

   A. Avoid priming, every time we start the pump
   B. Remove the contaminant present in the liquid
   C. Minimise the fluctuation in discharge
   D. Control the liquid discharge

9. 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

10. The net positive suction head (NPSH) of a centrifugal pump is defined as the sum of the velocity head and the pressure head at the_________________?

    A. Discharge
    B. Suction
    C. Suction minus vapor pressure of the liquid at suction temperature
    D. Discharge minus vapor pressure of the liquid at the discharge temperature