A. Impeller diameter or speed
B. Number of pumps and joining them in series
C. Number of pumps and joining them in parallel
D. All A., B. and C.
Related Mcqs:
- 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. - 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 - 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 - 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. - 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 - 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 - 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 - A centrifugal pump is called a turbine pump, if it is having a_________________?
A. Turbine type impeller
B. Vaned diffusion casing
C. Rotating vaned volute
D. None of these - 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 - 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
