A mixed flow centrifugal pump (A) Employs such an impeller, through which the flow is a combination of radial & axial flow (B) Mixes the two fluids before pumping them (C) Pumps the two fluids separately and then mixes them (D) Employs impellers in both the radial & axial directions

A mixed flow centrifugal pump
(A) Employs such an impeller, through which the flow is a combination of
radial & axial flow
(B) Mixes the two fluids before pumping them
(C) Pumps the two fluids separately and then mixes them
(D) Employs impellers in both the radial & axial directions
by

1 Answer

Answer :

(A) Employs such an impeller, through which the flow is a combination of
radial & axial flow
by

Related questions

Pick up the correct statement from the following regarding radial flow centrifugal pumps: (A) These are provided with volute type or turbine type casings (B) In involute type of radial flow centrifugal pump, the impeller discharges into a gradually expanding spiral casing (C) The efficiency of turbine type of radial flow centrifugal pump, is always higher than that of volute type (D) All the above

Description : Pick up the correct statement from the following regarding radial flow centrifugal pumps:  (A) These are provided with volute type or turbine type casings  (B) In involute type of radial flow ... centrifugal pump, is always higher than that of  volute type  (D) All the above 

Last Answer : (D) All the above 

Which of the following options will facilitate the achievement of a very high head (say 30 metres) in case of a centrifugal pump? (A) Increasing the impeller speed and the volute area (B) Increasing the number of vanes in the impeller (C) Mounting of two or more impellers in series on a single shaft (D) Either of (A), (B) or (C)

Description : Which of the following options will facilitate the achievement of a very high head (say 30 metres) in case of a centrifugal pump? (A) Increasing the impeller speed and the volute area (B) Increasing the number of vanes ... or more impellers in series on a single shaft (D) Either of (A), (B) or (C)

Last Answer : (C) Mounting of two or more impellers in series on a single shaft

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

Description : 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

Last Answer : (A) Axial

The capacity of a centrifugal pump Can be increased by increasing the (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)

Description : The capacity of a centrifugal pump Can be increased by increasing the (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)

Last Answer : (D) All (A), (B) and (C)

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)

Description : 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) ... the pump (C) Head of the liquid pumped (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Most commonly used pump for lifting water in water supply mains, is (A) Axial flow pump (B) Reciprocating pump (C) Rotary type pump (D) Centrifugal pumps

Description : Most commonly used pump for lifting water in water supply mains, is  (A) Axial flow pump  (B) Reciprocating pump  (C) Rotary type pump  (D) Centrifugal pumps 

Last Answer : (A) Axial flow pump 

Conversion of dynamic velocity head into static pressure head in a centrifugal pump is the result of : (a) Increasing area of flow between adjacent vanes from inlet to outlet (b) Difference in pressure between suction and delivery ends (c) Radial thrust in pumps (d) Stuffing Box

Description : Conversion of dynamic velocity head into static pressure head in a centrifugal pump is the result of : (a) Increasing area of flow between adjacent vanes from inlet to outlet (b) Difference in pressure between suction and delivery ends (c) Radial thrust in pumps (d) Stuffing Box

Last Answer : (b) Difference in pressure between suction and delivery ends

Design of the casing of centrifugal pump should be such as to minimise the (A) Back flow through impeller (B) Loss of kinetic head (C) Loss of static head (D) None of these

Description : Design of the casing of centrifugal pump should be such as to minimise the (A) Back flow through impeller (B) Loss of kinetic head (C) Loss of static head (D) None of these

Last Answer : (B) Loss of kinetic head

Propellers are (A) Axial flow mixers (B) Low speed impeller (C) Used for mixing liquids of high viscosity (D) Radial flow mixers

Description : Propellers are (A) Axial flow mixers (B) Low speed impeller (C) Used for mixing liquids of high viscosity (D) Radial flow mixers

Last Answer : (A) Axial flow mixers

High specific speed of a pump implies that, it is a/an __________ pump. (A) Centrifugal (B) Mixed flow (C) Axial flow (D) None of these

Description : High specific speed of a pump implies that, it is a/an __________ pump. (A) Centrifugal (B) Mixed flow (C) Axial flow (D) None of these

Last Answer : (C) Axial flow

Low specific speed of a pump implies that, it is a/an __________ pump. (A) Axial flow (B) Centrifugal (C) Mixed flow (D) None of these

Description : Low specific speed of a pump implies that, it is a/an __________ pump. (A) Axial flow (B) Centrifugal (C) Mixed flow (D) None of these

Last Answer : (B) Centrifugal

Height of liquid in agitation tank is normally maintained equal to the tank diameter. However, if the tank is too tall and a large liquid hold up is desired, then two or more impellers mounted on the same shaft may be used. The clearance between the tank bottom and the bottom most impeller should be about (where, D = impeller diameter) (A) 0.5 D (B) D (C) 1.5 D (D) 2 D

Description : Height of liquid in agitation tank is normally maintained equal to the tank diameter. However, if the tank is too tall and a large liquid hold up is desired, then two or more impellers mounted on the same shaft may be used. The ... where, D = impeller diameter) (A) 0.5 D (B) D (C) 1.5 D (D) 2 D

Last Answer : (B) D

Reciprocating pumps (A) Are not suitable for variable heads (B) Are four times costlier than centrifugal pumps (C) Are not suitable for pumping water containing sediments (D) Single stroke produce pulsating flow

Description : Reciprocating pumps  (A) Are not suitable for variable heads  (B) Are four times costlier than centrifugal pumps  (C) Are not suitable for pumping water containing sediments  (D) Single stroke produce pulsating flow 

Last Answer : (A) Are not suitable for variable heads 

Priming of a centrifugal pump is done to (A) Increase the mass flow rate of fluid (B) Develop effective pressure rise by the pump (C) Avoid chances of separation inside the impeller (D) None of these

Description : Priming of a centrifugal pump is done to (A) Increase the mass flow rate of fluid (B) Develop effective pressure rise by the pump (C) Avoid chances of separation inside the impeller (D) None of these

Last Answer : (C) Avoid chances of separation inside the impeller

In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes (A) Less than atmospheric pressure (B) More than liquid vapor pressure (C) Less than liquid vapor pressure (D) More than atmospheric pressure

Description : In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes (A) Less than atmospheric pressure (B) More than liquid vapor pressure (C) Less than liquid vapor pressure (D) More than atmospheric pressure

Last Answer : (C) Less than liquid vapor pressure

During agitation of liquids, the (A) Froude number is independent for the curves between power number and Reynolds number in baffled system (B) Power number becomes independent of impellers Reynolds number at high Reynolds number, but is dependent on the geometry of the impeller (C) Froude number is used to account for the effect of surface (e.g., the centre vortex) on the power number (D) All (A), (B) and (C)

Description : During agitation of liquids, the (A) Froude number is independent for the curves between power number and Reynolds number in baffled system (B) Power number becomes independent of impellers Reynolds number at high Reynolds number, ... , the centre vortex) on the power number (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

In case of a, centrifugal pump, the ratio h1/h2is termed as the __________ efficiency (where, h1 = actual measured head & h2 = head imparted to the fluid by impeller). (A) Mechanical (B) Overall (C) Volumetric (D) Impeller

Description : In case of a, centrifugal pump, the ratio h1/h2is termed as the __________ efficiency (where, h1 = actual measured head & h2 = head imparted to the fluid by impeller). (A) Mechanical (B) Overall (C) Volumetric (D) Impeller

Last Answer : A) Mechanical

Head developed by a centrifugal pump depends on its (A) Speed (B) Impeller diameter (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Head developed by a centrifugal pump depends on its (A) Speed (B) Impeller diameter (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : C) Both (A) and (B)

Which one of the following types of impeller vanes are most commonly used in centrifugal type compressors? A. Forward curved B. Radial C. Backward curved D. Tangential

Description : Which one of the following types of impeller vanes are most commonly used in centrifugal type compressors? A. Forward curved B. Radial C. Backward curved D. Tangential

Last Answer : ANSWER : C

A centrifugal pump designed for handling water (μ = 1 cp) will deliver __________ when pumping a thicker oil (μ = 30 cp). (A) Less head & capacity (B) More head (C) More capacity (D) Less head & more capacity

Description : A centrifugal pump designed for handling water (μ = 1 cp) will deliver __________ when pumping a thicker oil (μ = 30 cp). (A) Less head & capacity (B) More head (C) More capacity (D) Less head & more capacity

Last Answer : (A) Less head & capacity

Which of the following is most prone to pulsating discharge flow? (A) Centrifugal pump(B) Reciprocating pump(C) Gear pump(D) Axial flow pump

Description : Which of the following is most prone to pulsating discharge flow? (A) Centrifugal pump (B) Reciprocating pump (C) Gear pump (D) Axial flow pump

Last Answer : (C) Gear pump

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

Description : 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

Last Answer : (B) Head varies as the square of speed

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

Description : 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

Last Answer : (B) Type of casing

Theoretical head developed by a centrifugal pump does not depend upon the __________ the impeller. (A) Radius of (B) Speed of (C) Fluid velocity leaving (D) None of these

Description : Theoretical head developed by a centrifugal pump does not depend upon the __________ the impeller. (A) Radius of (B) Speed of (C) Fluid velocity leaving (D) None of these

Last Answer : (D) None of these

In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the __________ efficiency. (A) Manometric (B) Mechanical (C) Volumetric (D) Overall

Description : In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the __________ efficiency. (A) Manometric (B) Mechanical (C) Volumetric (D) Overall

Last Answer : (A) Manometric

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

Description : 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

Last Answer : (A) D = 1840 H0.5 /N

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)

Description : 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)

Last Answer : (D) All (A), (B) and (C)

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

Description : 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

Last Answer : (B) Vaned diffusion casing

The head developed by a centrifugal pump is largely determined by the (A) Power of the pump(B) Nature of the liquid being pumped(C) Angle of the vanes and the speed of the tip of the impeller(D) Vapour pressure of the liquid

Description : The head developed by a centrifugal pump is largely determined by the (A) Power of the pump (B) Nature of the liquid being pumped (C) Angle of the vanes and the speed of the tip of the impeller (D) Vapour pressure of the liquid

Last Answer : (C) Angle of the vanes and the speed of the tip of the impeller

In case of a centrifugal pump, the theoretical head developed is dependent on the __________ the impeller. (A) Speed of (B) Diameter of (C) Fluid velocity leaving (D) All (A), (B) and (C)

Description : In case of a centrifugal pump, the theoretical head developed is dependent on the __________ the impeller. (A) Speed of (B) Diameter of (C) Fluid velocity leaving (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Erosion and pits formation on the impeller of a centrifugal pump may be due to (A) Cavitation (B) Low speed of impeller (C) Its operation with delivery valve closed for considerable time after starting the pump (D) Off centering of pump with motor

Description : Erosion and pits formation on the impeller of a centrifugal pump may be due to (A) Cavitation (B) Low speed of impeller (C) Its operation with delivery valve closed for considerable time after starting the pump (D) Off centering of pump with motor

Last Answer : (A) Cavitation

Which of the following is not the function of a volute casing provided in a centrifugal pump? (A) To reduce the head loss in discharge (B) To increase the pump efficiency (C) To collect liquid from the periphery of the impeller and to transmit it to the delivery pipe at constant velocity (D) To increase the pump discharge rate

Description : Which of the following is not the function of a volute casing provided in a centrifugal pump? (A) To reduce the head loss in discharge (B) To increase the pump efficiency (C) To collect liquid ... and to transmit it to the delivery pipe at constant velocity (D) To increase the pump discharge rate

Last Answer : Option D

Two pumps M and N can separately fill a dumper in 36 minutes and 45 minutes respectively. Both the pumps are opened together but 12 minutes after the start the pump M is turned off. How much time will it take to fill the dumper? A) 9 min B) 10 min C) 30 min D) 32 min

Description : Two pumps M and N can separately fill a dumper in 36 minutes and 45 minutes respectively. Both the pumps are opened together but 12 minutes after the start the pump M is turned off. How much time will it take to fill the dumper? A) 9 min B) 10 min C) 30 min D) 32 min

Last Answer : C 12/36 + x/45 = 1 (12*5)/180+4x/180=1 60+4x=180 4x=120 X=120/4=30min

When using a pumping loop to mix two miscible fluids in a tank, when can the content are considered well mixed?

Description : When using a pumping loop to mix two miscible fluids in a tank, when can the content are considered well mixed?

Last Answer : A rule of thumb is to turn the tank over three (3) times and then sample the tank for mixture properties. By “turn the tank over”, we mean to force the entire volume of the tank through the pump at least three times. More turnovers may be necessary, but three times is a good starting point.

LMTD for evaporators & condensers for a given terminal parameters & set of conditions for counter-flow is equal to that for parallel flow. In such heat exchangers, with one of the fluids condensing or evaporating, the surface area required is the least in the __________ flow. (A) Parallel (B) Mixed (C) Counter flow (D) Same in either 'a', b' or 'c'

Description : LMTD for evaporators & condensers for a given terminal parameters & set of conditions for counter-flow is equal to that for parallel flow. In such heat exchangers, with one of the fluids condensing or evaporating, the surface ... Parallel (B) Mixed (C) Counter flow (D) Same in either 'a', b' or 'c'

Last Answer : (D) Same in either 'a', b' or 'c'

For pumping slurry, one can use a __________ pump. (A) Reciprocating (B) Diaphragm (C) Centrifugal (D) Pneumatic

Description : For pumping slurry, one can use a __________ pump. (A) Reciprocating (B) Diaphragm (C) Centrifugal (D) Pneumatic

Last Answer : (B) Diaphragm

Which of the following is used for pumping crude oil from oil well? (A) Single stage centrifugal pump (B) Gear pump (C) Screw pump (D) Duplex/triplex reciprocating pump

Description : Which of the following is used for pumping crude oil from oil well? (A) Single stage centrifugal pump (B) Gear pump (C) Screw pump (D) Duplex/triplex reciprocating pump

Last Answer : (D) Duplex/triplex reciprocating pump

Self-priming centrifugal pump can be used for (A) Booster service (B) Pumping liquid fertilisers (e.g. liquid NH3 ) (C) Pumping industrial wastes (D) All (A), (B) and (C)

Description : Self-priming centrifugal pump can be used for (A) Booster service (B) Pumping liquid fertilisers (e.g. liquid NH3 ) (C) Pumping industrial wastes (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Which of the following is the most common pump for pumping either raw sewage or sludge? (A) Electromagnetic pump (B) Centrifugal pump (C) Reciprocating pump(D) Gear pump

Description : Which of the following is the most common pump for pumping either raw sewage or sludge? (A) Electromagnetic pump (B) Centrifugal pump (C) Reciprocating pump (D) Gear pump

Last Answer : (C) Reciprocating pump

__________ is an example of axial flow impeller. (A) Paddle (B) Turbine (C) Propeller (D) All (A), (B) and (C)

Description : __________ is an example of axial flow impeller. (A) Paddle (B) Turbine (C) Propeller (D) All (A), (B) and (C)

Last Answer : (C) Propeller

Reciprocating pumps are not able to compete with the centrifugal pump for industrial use, mainly because these pumps have (A) Very low speeds (B) Smaller discharge (C) Higher capital &maintenance cost (D) High vibrations

Description : Reciprocating pumps are not able to compete with the centrifugal pump for industrial use, mainly because these pumps have (A) Very low speeds (B) Smaller discharge (C) Higher capital &maintenance cost (D) High vibrations

Last Answer : (C) Higher capital &maintenance cost

Power required for mixing Newtonian fluids is a function of the (A) Speed of impeller, diameter of impeller & viscosity (B) Density & viscosity of fluid only (C) Density of fluid, viscosity of fluid & impeller dia only (D) None of these

Description : Power required for mixing Newtonian fluids is a function of the (A) Speed of impeller, diameter of impeller & viscosity (B) Density & viscosity of fluid only (C) Density of fluid, viscosity of fluid & impeller dia only (D) None of these

Last Answer : (D) None of these

Which of the following pumps in used to pump sewage solids with liquid sewage without clogging the pump is? A. Centrifugal pump B. Pneumatic ejector C. Reciprocating pump D. None of these

Description : Which of the following pumps in used to pump sewage solids with liquid sewage without clogging the pump is? A. Centrifugal pump B. Pneumatic ejector C. Reciprocating pump D. None of these

Last Answer : ANS: A

A backmix reactor (A) Is same as plug-flow reactor (B) Is same as ideal stirred tank reactor (C) Employs mixing in axial direction only (D) Is most suitable for gas phase reaction

Description : A backmix reactor (A) Is same as plug-flow reactor (B) Is same as ideal stirred tank reactor (C) Employs mixing in axial direction only (D) Is most suitable for gas phase reaction

Last Answer : (B) Is same as ideal stirred tank reactor

__________ pumps are axial flow pumps. (A) Turbine (B) Propeller (C) Diffuser (D) None of these

Description : __________ pumps are axial flow pumps. (A) Turbine (B) Propeller (C) Diffuser (D) None of these

Last Answer : (B) Propeller

In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow? (A) Discharge of water by a centrifugal pump being run at a constant rpm (B) Water flow in the suction and discharge pipe of a reciprocating pump (C) Water discharge from a vertical vessel in which constant level is maintained (D) Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe

Description : In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow? (A) ... level is maintained (D) Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe

Last Answer : (B) Water flow in the suction and discharge pipe of a reciprocating pump

The Stoke's stream function applies to the (A) Irrotational flow only (B) Ideal/non i viscous fluids only (C) Cases of axial symmetry (D) None of these

Description : The Stoke's stream function applies to the (A) Irrotational flow only (B) Ideal/non i viscous fluids only (C) Cases of axial symmetry (D) None of these

Last Answer : (C) Cases of axial symmetry

Pick out the wrong statement pertaining to the turbine agitator. (A) Recommended peripheral speed for the turbine agitator is 200-250 metres/minute (B) Pitched blade turbine agitator gives only radial flow with complete absence of the axial flow (C) Generally, the diameter of the agitator is kept between l/3rd to l/6th of the tank diameter while the blade length is l/4th of agitator diameter (with central disc, it is l/8th of the agitator diameter)

Description : Pick out the wrong statement pertaining to the turbine agitator. (A) Recommended peripheral speed for the turbine agitator is 200-250 metres/minute (B) Pitched blade turbine agitator gives only radial flow with ... l/4th of agitator diameter (with central disc, it is l/8th of the agitator diameter)

Last Answer : (B) Pitched blade turbine agitator gives only radial flow with complete absence of the axial flow

Which of the following can be used to create a flow of gas, where no significant compression is required? (A) Reciprocating compressor (B) Blower (C) Axial flow compressor (D) Centrifugal compressor

Description : Which of the following can be used to create a flow of gas, where no significant compression is required? (A) Reciprocating compressor (B) Blower (C) Axial flow compressor (D) Centrifugal compressor

Last Answer : (B) Blower

Turbine impeller (A) Produces only radial current (B) Produces only tangential current (C) Is effective over wide range of viscosities (D) Does not produce tangential current

Description : Turbine impeller (A) Produces only radial current (B) Produces only tangential current (C) Is effective over wide range of viscosities (D) Does not produce tangential current

Last Answer : (C) Is effective over wide range of viscosities