Multistage centrifugal pumps are generally used for (A) High head (B) Low head but high discharge (C) Highly viscous liquid (D) Slurries of high solid concentration

Multistage centrifugal pumps are generally used for
(A) High head
(B) Low head but high discharge
(C) Highly viscous liquid
(D) Slurries of high solid concentration
by

1 Answer

Answer :

(A) High head
by

Related questions

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

Reciprocating pumps compared to centrifugal pumps (A) Deliver liquid at uniform pressure (B) Can handle slurries more efficiently (C) Are not subject to air binding (D) Can be operated with delivery valve closed

Description : Reciprocating pumps compared to centrifugal pumps (A) Deliver liquid at uniform pressure (B) Can handle slurries more efficiently (C) Are not subject to air binding (D) Can be operated with delivery valve closed

Last Answer : (C) Are not subject to air binding

Plunger pumps are used for (A) Higher pressure (B) Slurries (C) Viscous mass (D) None of these

Description : Plunger pumps are used for (A) Higher pressure (B) Slurries (C) Viscous mass (D) None of these

Last Answer : (A) Higher pressure

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

For centrifugal pumps (A) Initial cost is low (B) Limited space is required (C) The discharge obtained is steady and non-pulsating (D) All the above

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Last Answer : (D) All the above 

Leidenfrost point is a term concerned with the (A) Condensation of the saturated vapor on a cold surface (B) Concentration of a corrosive solution by evaporation (C) Heat transfer between two highly viscous liquids (D) Boiling of a liquid on a hot surface

Description : Leidenfrost point is a term concerned with the (A) Condensation of the saturated vapor on a cold surface (B) Concentration of a corrosive solution by evaporation (C) Heat transfer between two highly viscous liquids (D) Boiling of a liquid on a hot surface

Last Answer : (D) Boiling of a liquid on a hot surface

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

Diaphragm pumps are used to transport (A) Solids (B) Liquids (C) Fluids (D) Slurries

Description : Diaphragm pumps are used to transport (A) Solids (B) Liquids (C) Fluids (D) Slurries

Last Answer : (D) Slurries

Check in a centrifugal pump is (A) Provided in the discharge line (B) Generally a globe valve (C) Provided to prevent liquid from backing up through the pump when the pump is turned off or accidently stops running (D) All (A), (B) and (C)

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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)

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

Description : 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 ... of the liquid at suction temperature (D) Discharge minus vapor pressure of the liquid at the discharge temperature

Last Answer : (C) Suction minus vapor pressure of the liquid at suction temperature

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

Description : 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 ... of the liquid at suction temperature (D) Discharge minus vapor pressure of the liquid at the discharge temperature

Last Answer : (C) Suction minus vapor pressure of the liquid at suction temperature

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

Propeller type centrifugal pumps are most suitable for (A) High capacity at high heads (B) High capacity at low heads (C) Low capacity at high heads (D) Low capacity at low heads

Description : Propeller type centrifugal pumps are most suitable for (A) High capacity at high heads (B) High capacity at low heads (C) Low capacity at high heads (D) Low capacity at low heads

Last Answer : (B) High capacity at low heads

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

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Last Answer : (C) Less than liquid vapor pressure

Boiler feed water pump is usually a __________ pump.(A) Reciprocating (B) Gear (C) Multistage centrifugal (D) Diaphragm

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Last Answer : (C) Multistage centrifugal

In multistage equilibrium conversion of SO2 to SO3 (2SO2 + O2 ⇌ 2SO3 ), the reverse reaction becomes appreciable at a temperature of 550° C. The percentage equilibrium conversion of SO2 to SO3 can be increased by (A) Increasing the oxygen concentration (B) Putting more quantity of V2O5 catalyst in the converter (C) Removing some quantity of SO3 during intermediate stage (D) Maintaining low temperature & pressure in the converter

Description : In multistage equilibrium conversion of SO2 to SO3 (2SO2 + O2 ⇌ 2SO3 ), the reverse reaction becomes appreciable at a temperature of 550° C. The percentage equilibrium conversion of SO2 to ... some quantity of SO3 during intermediate stage (D) Maintaining low temperature & pressure in the converter

Last Answer : (C) Removing some quantity of SO3 during intermediate stage

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)

Description : 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)

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

Turbulent flow generally occurs for cases involving (A) Highly viscous fluid (B) Very narrow passages (C) Very slow motion (D) None of these

Description : Turbulent flow generally occurs for cases involving (A) Highly viscous fluid (B) Very narrow passages (C) Very slow motion (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

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Last Answer : ANS: A

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

Two identical pumps, each capable of delivering 0.2 cumec, against a head of 30 m, are connected in parallel. The resulting discharge is : a) 0.4 cumec against a head of 30 m b) 0.4 cumec against a head of 60 m c) 0.2 cumec against a head of 30 m d) 0.2 cumec against a head of 60 m

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Last Answer : a) 0.4 cumec against a head of 30 m

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

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Last Answer : (D) Increase the discharge

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

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

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

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

Description : 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

Last Answer : (A) 500

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*

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Last Answer : e) all of the above*

Most of the centrifugal pumps used in chemical plants are usually __________ driven. (A) Steam (B) Diesel engine (C) Electric motor (D) Gas turbine

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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

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

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)

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

Helical screw agitator is used for (A) Mixing highly viscous pastes (B) Blending immiscible liquids (C) Mixing liquids at very high temperature (> 250 °C) (D) None of these

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Last Answer : (A) Mixing highly viscous pastes

Semibatch reactor is preferred, when a/an (A) A highly exothermic reaction is to be controlled (B) Undesirable side reaction (at high concentration of one of the reactants) is to be avoided (C) A gas is to be reacted with liquid (e.g. hydrogenation of fat) (D) All (A), (B), and (C

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

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Last Answer : (A) Jacketed liquid phase CSTR

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Last Answer : (D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation

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

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Forces acting on a particle settling in fluid are __________ forces. (A) Gravitational & buoyant (B) Centrifugal & drag (C) Gravitational or centrifugal buoyant drag (D) External, drag & viscous

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Last Answer : (C) Gravitational or centrifugal buoyant drag

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Last Answer : (D) All the above 

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

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Why Cavitation Will Occur In Centrifugal Pumps And Not In Displacement Pumps?

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When milk is churned, the cream separates from it due to: (1) Frictional force (2) Centrifugal force (3) Gravitational force (4) Viscous forces

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