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?

Related Mcqs:

1. 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

2. At a constant speed of the centrifugal pump, it‟s _____________ the impeller diameter?

   A. Capacity varies directly with
   B. Head varies as the square of
   C. Horsepower varies as the cube of
   D. All A., B. and C.

3. With a constant diameter impeller of a centrifugal pump _____________________?

   A. Its capacity varies directly as the square of speed
   B. Head varies as the square of speed
   C. Horsepower input varies as the square of speed
   D. Head varies as the speed

4. Specific speed of a centrifugal pump relates it with another pump having the___________________?

   A. Dynamic similarity
   B. Same efficiency
   C. Same speed
   D. Geometrical similarity

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 has the following specifications: Power = 4 H.P.; Speed = 800 rpm Head = 8 metres Flow = 1000 litres/minutes. If its speed is halved, the new discharge will be __________ litres/minute ?

   A. 500
   B. 200
   C. 1000
   D. 750

7. 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

8. The blades of a centrifugal impeller are said to be curved forward, if the ____________ of the motion of impeller blades?

   A. Inlet tip of a blade curves in a direction opposite to that
   B. Outlet tip of a blade curves in a direction opposite to that
   C. Inlet tip of a blade is towards the direction
   D. Outlet tip of a blade is towards the direction

9. 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

10. 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.