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

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
by

1 Answer

Answer :

(C) Avoid chances of separation inside the impeller
by

Related questions

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

Description : 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

Last Answer : (A) Avoid priming, every time we start the pump

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

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 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)

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

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

Description : 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

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

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

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 

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

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

Function of air vessel provided in a reciprocating pump is to (A) Reduce discharge fluctuation (B) Reduce the danger of cavitation (C) Avoid the necessity of priming (D) Increase the pump efficiency

Description : Function of air vessel provided in a reciprocating pump is to (A) Reduce discharge fluctuation (B) Reduce the danger of cavitation (C) Avoid the necessity of priming (D) Increase the pump efficiency

Last Answer : (A) Reduce discharge fluctuation

The pressure rise in the impeller of centrifugal compressor is achieved by A. the decrease in volume and diffusion action B. the centrifugal action and decrease in volume C. the centrifugal and diffusion action D. the centrifugal and push pull action

Description : The pressure rise in the impeller of centrifugal compressor is achieved by A. the decrease in volume and diffusion action B. the centrifugal action and decrease in volume C. the centrifugal and diffusion action D. the centrifugal and push pull action

Last Answer : ANSWER : D

A centrifugal pump loses prime after starting. The reason of this trouble may be (A) Incomplete priming (B) Too high a suction lift (C) Low available NPSH and air leaks in the suction pipe (D) All (A), (B), and (C)

Description : A centrifugal pump loses prime after starting. The reason of this trouble may be (A) Incomplete priming (B) Too high a suction lift (C) Low available NPSH and air leaks in the suction pipe (D) All (A), (B), and (C)

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

Priming is needed in a __________ pump. (A) Reciprocating (B) Gear (C) Centrifugal (D) Diaphragm

Description : Priming is needed in a __________ pump. (A) Reciprocating (B) Gear (C) Centrifugal (D) Diaphragm

Last Answer : (C) Centrifugal

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)

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)

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

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

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

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 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

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

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)

Centrifugal pumps as compared to reciprocating pumps (A) Run at a lower speed for the same discharge (B) Do not need priming (C) Deliver fluid with pulsating/fluctuating discharge (D) Can be run with discharge line valve closed for a short interval

Description : Centrifugal pumps as compared to reciprocating pumps (A) Run at a lower speed for the same discharge (B) Do not need priming (C) Deliver fluid with pulsating/fluctuating discharge (D) Can be run with discharge line valve closed for a short interval

Last Answer : (D) Can be run with discharge line valve closed for a short interval

The main draw-back of centrifugal pump, is (A) Necessity of priming (B) Discharge from pump varies with the load of water (C) For high heads, efficiency is low up to 50% (D) All the above

Description : The main draw-back of centrifugal pump, is (A) Necessity of priming (B) Discharge from pump varies with the load of water (C) For high heads, efficiency is low up to 50% (D) All the above

Last Answer : (D) All the above

The main drawback of centrifugal pump is a)necessity of priming b) discharge from pump varies with the load of water c) For high heads efficiency is low up to 50% d) the suction lift is limited to 6 metre e) all of the above*

Description : The main drawback of centrifugal pump is a)necessity of priming b) discharge from pump varies with the load of water c) For high heads efficiency is low up to 50% d) the suction lift is limited to 6 metre e) all of the above*

Last Answer : e) all of the above*

Check valve provided in the discharge line of a centrifugal pump serves the purpose of controlling the (A) Back flow of fluid in the event of stoppage of pump (B) Discharge pressure (C) Flow of liquid during operation of the pump (D) All (A), (B) and (C)

Description : Check valve provided in the discharge line of a centrifugal pump serves the purpose of controlling the (A) Back flow of fluid in the event of stoppage of pump (B) Discharge pressure (C) Flow of liquid during operation of the pump (D) All (A), (B) and (C)

Last Answer : (A) Back flow of fluid in the event of stoppage of pump

Circulation pump is located below the evaporator to (A) Avoid cavitation (B) Avoid frequent priming (C) Create more suction head (D) None of these

Description : Circulation pump is located below the evaporator to (A) Avoid cavitation (B) Avoid frequent priming (C) Create more suction head (D) None of these

Last Answer : (C) Create more suction head

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

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

To handle smaller quantity of fluid at higher discharge pressure, use a __________ pump. (A) Reciprocating (B) Centrifugal (C) Volute (D) Rotary vacuum

Description : To handle smaller quantity of fluid at higher discharge pressure, use a __________ pump. (A) Reciprocating (B) Centrifugal (C) Volute (D) Rotary vacuum

Last Answer : (A) Reciprocating

Which one of the following statements is correct? A. Reciprocating compressors are used to supply large quantities of air at a lower pressure ratio B. Centrifugal compressors are used to supply large quantities of air at a lower pressure ratio C. Centrifugal compressors are used to supply small quantities of air at a lower pressure ratio D. Centrifugal compressors cannot be run at high speed because of impeller, diffuser and casing.

Description : Which one of the following statements is correct? A. Reciprocating compressors are used to supply large quantities of air at a lower pressure ratio B. Centrifugal compressors are used to supply ... . Centrifugal compressors cannot be run at high speed because of impeller, diffuser and casing.

Last Answer : ANSWER : B

With increasing flow rate, the hydraulic efficiency of a centrifugal pump (A) Monotonically decreases (B) Decreases and then increases(C) Remains constant(D) Increases and then decreases

Description : With increasing flow rate, the hydraulic efficiency of a centrifugal pump (A) Monotonically decreases (B) Decreases and then increases (C) Remains constant (D) Increases and then decreases

Last Answer : (A) Monotonically decreases

The most important factor, which determines the maximum height to which water can be lifted by a pump at standard temperature is the (A) Barometric pressure (B) Speed of the impeller (C) Diameter of the impeller (D) Both (B) and (C)

Description : The most important factor, which determines the maximum height to which water can be lifted by a pump at standard temperature is the (A) Barometric pressure (B) Speed of the impeller (C) Diameter of the impeller (D) Both (B) and (C)

Last Answer : (A) Barometric pressure

A centrifugal pump used to pump water is used to pump an oil withspecific 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

Description : A centrifugal pump used to pump water is used to pump an oil withspecific 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

Last Answer : (B) Decrease

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

Description : 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 ... Inlet tip of a blade is towards the direction (D) Outlet tip of a blade is towards the direction

Last Answer : (D) Outlet tip of a blade is towards the direction

Horsepower increase of a centrifugal gas compressor without altering the volumetric flow rate will __________ the gas discharge pressure. (A) Increase (B) Decrease (C) Not change (D) Exponentially decrease

Description : Horsepower increase of a centrifugal gas compressor without altering the volumetric flow rate will __________ the gas discharge pressure. (A) Increase (B) Decrease (C) Not change (D) Exponentially decrease

Last Answer : (A) Increase

Volute type of casing is provided in a centrifugal pump to (A) Convert velocity head to pressure head (B) Convert pressure head to velocity head (C) Reduce the discharge fluctuation (D) Increase the discharge

Description : Volute type of casing is provided in a centrifugal pump to (A) Convert velocity head to pressure head (B) Convert pressure head to velocity head (C) Reduce the discharge fluctuation (D) Increase the discharge

Last Answer : (D) Increase the discharge

While starting a centrifugal pump, its delivery valve should be kept (A) Opened (B) Closed (C) Either opened or closed; it does not make any difference (D) Either opened or closed; depending on the fluid viscosity

Description : While starting a centrifugal pump, its delivery valve should be kept (A) Opened (B) Closed (C) Either opened or closed; it does not make any difference (D) Either opened or closed; depending on the fluid viscosity

Last Answer : (B) Closed

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

Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation (B) Cavitation may be caused due to boiling of liquid by decreasing the pressure resulting in formation & collapse of vapor cavities (C) Cavitation begins at higher static pressure and lower velocity in larger diameter pipelines resulting in audible noise(D) Large scale cavitation cannot damage pipeline, restrict fluid flow anddamage steam turbine blades

Description : Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation ... (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

Last Answer : (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co￾efficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8

Description : A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co￾efficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8

Last Answer : (B) d -0.2

Steam distillation is used to (A) Reduce the number of plates (B) Avoid thermal decomposition of a component (C) Increase the efficiency of separation (D) Increase the total pressure of distillation

Description : Steam distillation is used to (A) Reduce the number of plates (B) Avoid thermal decomposition of a component (C) Increase the efficiency of separation (D) Increase the total pressure of distillation

Last Answer : (B) Avoid thermal decomposition of a component

Consider the following statements: Air vessels are fitted on the suction and delivery sides of a reciprocating pump to 1. Achieve higher speed without separation. 2. Reduce work in overcoming frictional resistance. 3. Avoid excessive vibration permanently. 4. Have nearly uniform discharge. Which of these statements are corrects? (a) 1, 2 & 4 only (b) 1, 2 & 3 only (c) 2, 3 & 4 only (d) 1, 2, 3 & 4

Description : Consider the following statements: Air vessels are fitted on the suction and delivery sides of a reciprocating pump to 1. Achieve higher speed without separation. 2. Reduce work in overcoming frictional resistance. 3. Avoid excessive vibration ... 2 & 3 only (c) 2, 3 & 4 only (d) 1, 2, 3 & 4

Last Answer : (d) 1, 2, 3 & 4

Pick out the wrong statement. (A) A fluid mass is free from shearing forces, when it is made to rotate with a uniform velocity(B) Newton's law of viscosity is not applicable to the turbulent flow of fluidwith linear velocity distribution(C) Laminar flow of viscous liquids is involved in the lubrication of varioustypes of bearings(D) Rise of water in capillary tubes reduces with the increasing diameter ofcapillary tubes

Description : Pick out the wrong statement. (A) A fluid mass is free from shearing forces, when it is made to rotate with a uniform velocit (B) Newton's law of viscosity is not applicable to the ... types of bearings (D) Rise of water in capillary tubes reduces with the increasing diameter of capillary tubes

Last Answer : (B) Newton's law of viscosity is not applicable to the turbulent flow of fluid with linear velocity distribution

In centrifugal compressor terminology, vaneless space refers to the space between A. The inlet and blade inlet edge B. Blades in the impeller C. Diffuser exit and volute casing D. Impeller tip and diffuser inlet edge

Description : In centrifugal compressor terminology, vaneless space refers to the space between A. The inlet and blade inlet edge B. Blades in the impeller C. Diffuser exit and volute casing D. Impeller tip and diffuser inlet edge

Last Answer : ANSWER : D

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

In liquid extraction, if the selectivity is unity, then (A) Separation of the constituents is the most effective (B) No separation will occur (C) Amount of solvent required will be minimum (D) Solvent flow rate should be very low

Description : In liquid extraction, if the selectivity is unity, then (A) Separation of the constituents is the most effective (B) No separation will occur (C) Amount of solvent required will be minimum (D) Solvent flow rate should be very low

Last Answer : (B) No separation will occur