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Multiple choice question for engineering

Set 1

1. When a pump casing is filled with liquid before it is started, it is called as _________
a) Adiabatic expansion
b) Priming
c) Adiabatic compression
d) Isentropic expansion

View Answer

Answer: b [Reason:] When a pump casing is filled with liquid before it is started, it is called as priming. Most of the centrifugal pumps are not self priming. At this stage, the pump will not be able to function.

2. The pump will become incapable of pumping in case of _______
a) Gas bounding
b) Throttle bush
c) Stuffing box
d) Casing breakage

View Answer

Answer: d [Reason:] For an oil field to have solid control, it needs centrifugal pumps. At each stage in the centrifugal pump, the fluid is directed to towards the centre. This makes it more efficient in operating a large oil field.

3. Priming is needed when impeller cannot impart enough _________
a) Draft speed
b) Energy
c) Pressure
d) Heat

View Answer

Answer: b [Reason:] Priming is needed when impeller cannot impart enough energy. Therefore priming is compulsory in this case.

4. Priming performs response using ________
a) Stimulus
b) Froth
c) Slurry
d) Heat

View Answer

Answer: a [Reason:] Priming performs response using a stimulus. It is an implicit method in which exposure to flow of fluid takes place.

5. To avoid gas bounding, the pump is _________
a) Heated
b) Elevated
c) Primed
d) Charged

View Answer

Answer: c [Reason:] Centrifugal pumps work under the same principle, but differ in their functions. At each stage in the centrifugal pump, the fluid is directed to towards the centre. To avoid gas bounding, the pump is primed.

6. Centrifugal pumps are located ________ the level of source
a) Below
b) Above
c) Parallel with
d) Series with

View Answer

Answer: a [Reason:] Centrifugal pumps are located below the level of source. It is located in such way because, it takes away the suction at a faster rate.

7. A pump that can evacuate air is called as _________
a) Series pumps
b) Self priming pumps
c) Froth pumps
d) Drive pumps

View Answer

Answer: b [Reason:] A pump that can evacuate air is called as self priming pumps. In normal conditions, it is difficult for centrifugal pumps to evacuate the air from the inlet line leading to a fluid level to a different altitude.

8. What does CPO stand for?
a) Centrifugal pump operation
b) Centrifugal part operation
c) Centrifugal pump output
d) Centrifugal part output

View Answer

Answer: a [Reason:] CPO stands for centrifugal pump operation. It has got a pump start off procedure and pump shut down procedure.

9. Self priming pumps overshadow the function of __________
a) Self auxiliary device
b) Wear rate
c) Corrosion device
d) Cavitation device

View Answer

Answer: a [Reason:] Self priming pumps overshadow the function of self auxiliary device. A pump that can evacuate air is called as self priming pumps. In normal conditions, it is difficult for centrifugal pumps to evacuate the air from the inlet line leading to a fluid level to a different altitude.

10. What is necessary for self priming to take place?
a) Draft tube
b) Pump casing
c) Suspended solenoids
d) Turbine head

View Answer

Answer: b [Reason:] For self priming to take place, pump casing is necessary. This helps to evacuate air in normal conditions.

11. Centrifugal pumps with an internal suction stage are called as _________
a) Series pumps
b) Self priming pumps
c) Froth pumps
d) Drive pumps

View Answer

Answer: b [Reason:] Centrifugal pumps with an internal suction stage are called as self priming pumps. A pump that can evacuate air is called as self priming pumps. In normal conditions, it is difficult for centrifugal pumps to evacuate the air from the inlet line leading to a fluid level to a different altitude.

12. Two phase mixture is pumped unit the suction line is evacuated.
a) True
b) False

View Answer

Answer: a [Reason:] Two phase mixture is pumped unit the suction line is evacuated as the pump operates without a foot valve and without an evacuation device on the suction side. The pump has to be primed for this purpose.

13. During normal working operation, the pump works like __________
a) Centrifugal pumps
b) Self priming pumps
c) Froth pumps
d) Drive pumps

View Answer

Answer: a [Reason:] Pump shaft is not always supported by bearings. Since the pumps have no bearing support. The pumps are provided with a housing. During normal working operation, the pump works like centrifugal pumps.

14. The pump function that works on rinsing is called as dialysis of pump.
a) True
b) False

View Answer

Answer: a [Reason:] Yes, The pump function that works on rinsing is called as dialysis of pump.

15. What is purpose of vent valve in a pump?
a) High pressure control
b) High temperature control
c) Froths are generated can be minimized
d) To prevent siphon action

View Answer

Answer: d [Reason:] The main function of a suction swindle valve or vent valve in a centrifugal pump is to prevent any siphon action and ensure that the fluid remains in the casing when the pump has been stopped.

Set 2

1. Specific speed is denoted by ________
a) N
b) n
c) Ns
d) S

View Answer

Answer: c [Reason:] Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

2. Specific speeds are used in pumps to determine ________
a) Temperature
b) Reaction speed
c) Suction specific speed
d) Wheel speed

View Answer

Answer: c [Reason:] Specific speeds are used in pumps to determine. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

3. The tube at the exit of the nozzle increases the _______
a) Temperature
b) Pressure
c) Volume of the flow
d) Density of flow

View Answer

Answer: b [Reason:] The draft tube at the exit of the nozzle increases the pressure in the fluid. It increases it at the expense of its velocity. This means that the turbine can reduce its pressure without fear of back flow to the tail race.

4. Specific speed is used to characterize _______
a) Turbomachinery speed
b) Flow speed
c) Energy flow
d) Heat generated

View Answer

Answer: a [Reason:] Specific speed is used to characterize Turbomachinery speed. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

5. Specific speed predicts the shape of a/an _________
a) Pump
b) Density head
c) Impeller
d) Motor

View Answer

Answer: c [Reason:] Specific speed predicts the shape of an impeller. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

6. What helps in categorizing the impellers?
a) Quasi static number
b) Rotor
c) Height of draft tube
d) Pump

View Answer

Answer: a [Reason:] The impellers are categorized using a quasi static non dimensional number. It helps in determining the impellers time and proportional quantities.

7. Imperial units is defined as _________
a) Temperature by pressure
b) Tail race and head race
c) Revolutions per minute
d) Turbine performance

View Answer

Answer: c [Reason:] In Imperial units it is defined as the speed in revolutions per minute at which a geometrically similar impeller would operate if it were of such a size as to deliver one gallon per minute against one foot of hydraulic head.

8. Ratio of pump or turbine with reference pump or turbine is called as _________
a) Efficiency
b) Performance
c) Heat generated
d) Relative velocity

View Answer

Answer: b [Reason:] Ratio of pump or turbine with reference pump or turbine is called as the performance of that particular turbine or pump.

9. Low specific speed in hydraulic head is developed due to _________
a) Mass flow rate
b) Increase in temperature
c) Centrifugal force
d) Increase in pressure

View Answer

Answer: c [Reason:] Low specific speed with a radial flow in impellers are developed in hydraulic head principally due to centrifugal force. Pumps having higher specific speed develop a head that is partly by axial force.

10. Centrifugal pump impellers have speed ranging from ________
a) 500- 10000
b) 50- 100
c) 200-300
d) 0-50

View Answer

Answer: a [Reason:] Centrifugal pump impellers have speed ranging from 500- 10000 English units. IT has got radial flow with pumps mixed with axial flow pumps.

11. What is the unit of specific speed in metric system?
a) m.s
b) m/s
c) m3/s
d) m

View Answer

Answer: c [Reason:] The unit of specific speed in the metric system is given as m3/s. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery.

12. Specific speed develop a hydraulic flow through the centrifugal pumps.
a) True
b) False

View Answer

Answer: a [Reason:] Specific speed develop a hydraulic flow through the centrifugal pumps. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. With the increase in specific speeds, diameter of the impellers increases.

13. Net suction speed is used in problems with cavitation.
a) True
b) False

View Answer

Answer: a [Reason:] Net suction speed is used in problems with cavitation during the pump’s operation on the suction side. It is defined by centrifugal and axial pump.

14. Low specific speed in hydraulic head is developed due to _________
a) Mass flow rate
b) Increase in temperature
c) Centrifugal force
d) Increase in pressure

View Answer

Answer: c [Reason:] Low specific speed with a radial flow in impellers are developed in hydraulic head principally due to centrifugal force. Pumps having higher specific speed develop a head that is partly by axial force.

15. The runner diameter in a turbine is denoted as __________
a) A
b) Dr
c) Rr
d) De

View Answer

Answer: d [Reason:] The runner diameter in a turbine is denoted as ‘De’. Its SI unit is meters. It plays an essential role in improving the efficiency of the turbine. As the efficiency of the turbine is related to its design and structure.

Set 3

1. Reciprocating pump is a ________
a) Negative displacement pump
b) Positive displacement pump
c) Diaphragm pump
d) Emulsion pump

View Answer

Answer: b [Reason:] Reciprocation pump is a type of positive displacement pump. It has a piston pump, plunger and diaphragm. Reciprocating pumps have a good life provided that they are not left untouched.

2. What happens to the reciprocating pump when left untouched?
a) Efficiency decreases
b) Wear and tear
c) Surface expansion
d) Pressure change

View Answer

Answer: c [Reason:] When left untouched over a period of time, the reciprocating pump undergoes wear and tear. Reciprocating pumps have a good life provided that they are not left untouched.

3. Reciprocating pumps operate by drawing ______ into the chamber
a) Liquid
b) Pressure
c) Heat
d) Electricity

View Answer

Answer: a [Reason:] Reciprocating pumps operate by drawing liquid into the chamber or the cylinder with the help of a piston.

4. The cylinder of reciprocating cylinder is made up of _______
a) Cast iron
b) Wrought iron
c) Aluminium
d) Copper

View Answer

Answer: a [Reason:] The cylinder of reciprocating cylinder is made up of cast iron. Sometimes it is also made of steel alloy. The movement of piston is obtained by a connecting rod which connects piston and rotating crank inside the cylinder.

5. The higher discharge valve line holds the discharge valve ________
a) Open
b) Closed
c) Stop functioning
d) Automatic

View Answer

Answer: b [Reason:] The higher discharge valve line holds the discharge valve closed. This helps in maintaining the valve safely.

6. Reciprocating pumps are also called as __________
a) Force pumps
b) Mass Pumps
c) Heat pumps
d) Speed pumps

View Answer

Answer: a [Reason:] Reciprocating pumps are also called as force pumps. It helps to lift the liquid by the help of a pressure and thus it is called as a force pump.

7. Reciprocating pumps are classified according to ___________
a) Drag force
b) Number of cylinders
c) Shock waves
d) Flow speed

View Answer

Answer: b [Reason:] Reciprocating pumps are classified according to the number of cylinders. And also it classified according to the number of piston sides.

8. Simple hand operating pump is also called as ______
a) Froth pump
b) Bicycle pump
c) Multistage pumps
d) Centrifugal pumps

View Answer

Answer: b [Reason:] Simple hand operating pump is also called as bicycle pumps. It is the simplest pump that is used to inflate bicycle tires and various sporting balls.

9. Internal cavitation in reciprocating pumps occurs due to __________
a) Drag force
b) Cyclic stress
c) Shock waves
d) Flow speed

View Answer

Answer: c [Reason:] At high pressure, the voids can generate shock waves. Cavitation usually occurs due to the changes in pressure. The pressure change is so rapid that it leads to formation of liquid free layers or cavities that start to affect the overall performance.

10. Bicycle pump generates more compression than volume displacement.
a) True
b) False

View Answer

Answer: a [Reason:] Bicycle pump generates more compression than volume displacement. Simple hand operating pump is also called as bicycle pumps. It is the simplest pump that is used to inflate bicycle tires and various sporting balls.

11. Power operated pump in which only one side engages the fluid displacement is called _______
a) Froth pump
b) Single acting
c) Double acting
d) Bicycle pump

View Answer

Answer: b [Reason:] Power operated pump in which only one side engages the fluid displacement is called as single acting reciprocating pump. It consists of piston in only one side of the fluid being displaced.

12. Operation of reciprocating motion is done by a ________ source
a) Power
b) Energy
c) Momentum
d) Inertia

View Answer

Answer: a [Reason:] Operation of reciprocating motion is done by a power source. This power source consists of electric motor or IC engines. Power source gives rotary motion to crank.

13. An up and down back and forth relative linear motion is called __________
a) Reciprocation
b) Rotation
c) Filtration
d) Excavation

View Answer

Answer: a [Reason:] An up and down back and forth relative linear motion is called reciprocation. This is how the piston in a reciprocating pump moves.

14. Power operated pump in which only both sides engage the fluid displacement is called _____
a) Froth pump
b) Single acting
c) Double acting
d) Bicycle pump

View Answer

Answer: c [Reason:] Power operated pump in which both the side engages the fluid displacement is called as double acting reciprocating pump. It consists of piston in both the side of the fluid being displaced.

15. High pressure reciprocating pumps are generally from 1500 HP.
a) True
b) False

View Answer

Answer: a [Reason:] Yes, it is true. High pressure reciprocating pumps are generally, from 1500 HP. They have a pressure of 20000 PSI and flow rates up to 1000 GPM.

Set 4

1. Specific speed is the speed of the turbine which is similar to its ________
a) Temperature difference
b) Pressure difference
c) Aspect ratio
d) Speed of rotor

View Answer

Answer: c [Reason:] Specific speed is the speed of the turbine which is similar to its aspect ratio. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

2. Specific speeds are used in pumps to determine ________
a) Temperature
b) Reaction speed
c) Suction specific speed
d) Wheel speed

View Answer

Answer: c [Reason:] Specific speeds are used in pumps to determine. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

3. Specific speed develops a unit power under a unit _______
a) Temperature
b) Pressure
c) Volume of the flow
d) Head

View Answer

Answer: d [Reason:] Specific speed develops a unit power under a unit head of the turbine. The unit head of the turbine plays an important role in denoting the specific speed of the turbine.

4. Impeller in a motor is used to _________
a) Change temperatures
b) Change Pressure
c) Kinetic energy change
d) Change density

View Answer

Answer: b [Reason:] Impellers that are present in motors are used to increase or decrease the pressure of the fluid flow in the turbines. Thus, the correct option is ‘b’.

5. Hydraulic head is also called as _________
a) Pressure head
b) Density head
c) Kinetic head
d) Piezometric head

View Answer

Answer: d [Reason:] Hydraulic head is also called a Piezometric head. It is a measurement of the liquid pressure above the geodetic datum. Hydraulic head is usually measured as a liquid in surface elevation.

6. Specific speed of a Pelton wheel with single jet is _______
a) 8.5 to 30
b) 30 to 51
c) 51 to 225
d) 230 to 500

View Answer

Answer: a [Reason:] Specific speed of a Pelton wheel with a single jet is equal to 8.5 to 30. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

7. Specific speed is an index used to predict _______
a) Head race distance
b) Tail race distance
c) Tank dimensions
d) Turbine performance

View Answer

Answer: d [Reason:] Specific speed of a turbine is used to predict its turbine performance. Specific speeds are used in pumps to determine. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery.

8. Specific speed of a Pelton wheel with multiple jets is _______
a) 8.5 to 30
b) 30 to 51
c) 51 to 225
d) 230 to 500

View Answer

Answer: b [Reason:] Specific speed of a Pelton wheel with multiple jets is equal to 30 to 51. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

9. Specific speed of a Francis turbine is _______
a) 8.5 to 30
b) 30 to 51
c) 51 to 225
d) 230 to 500

View Answer

Answer: c [Reason:] Specific speed of a Francis turbine is equal to 51 to 225. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

10. Specific speed of a Kaplan turbine is _______
a) 8.5 to 30
b) 30 to 51
c) 51 to 225
d) 355 to 860

View Answer

Answer: d [Reason:] Specific speed of a Kaplan turbine is equal to 51 to 225. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. Some of the main examples of turbomachinery are turbines. Specific speed plays an important role in the turbine.

11. Specific speed less than 500 are called _________
a) Positive displacement pumps
b) Negative displacement pumps
c) Draft tubes
d) Tanks

View Answer

Answer: a [Reason:] Specific speed less than 500 are called positive displacement pumps. Centrifugal pump impellers have speed ranging from 500- 10000 English units. IT has got radial flow with pumps mixed with axial flow pumps.

12. With the increase in specific speeds, ________
a) Head race distance increases
b) Tail race distance increases
c) Tank dimensions increases
d) Diameters of impeller increases

View Answer

Answer: d [Reason:] Specific speed of a turbine is used to predict its turbine performance. Specific speeds are used in pumps to determine. Specific speed is denoted by Ns. It is used to characterize speeds in turbo machinery. With the increase in specific speeds, diameter of the impellers increases.

13. Specific speed is used to predict desired pump or turbine performance.
a) True
b) False

View Answer

Answer: a [Reason:] Specific speed is used to predict desired pump or turbine performance. It predicts the general shape of the impeller. Thus, it is a true statement.

14. Once we know the desired functions of the specific speed, it is easier to calculate its components units.
a) True
b) False

View Answer

Answer: a [Reason:] Yes, Once we know the desired functions of the specific speed, it is easier to calculate its components units. Specific speed is used to predict desired pump or turbine performance. It predicts the general shape of the impeller.

Set 5

1. The energy usage of a pump is determined by _______
a) Adiabatic expansion
b) Power required
c) Adiabatic compression
d) Isentropic expansion

View Answer

Answer: b [Reason:] The energy usage of a pump is determined by power required. Thus, it plays an important role in determining the amount of energy that a pump dissipates during its operation. It is with respect to the length of time.

2. For an oil field to have solid control, it needs _______
a) Draft tubes
b) Throttle bush
c) Stuffing box
d) Centrifugal pumps

View Answer

Answer: d [Reason:] For an oil field to have solid control, it needs centrifugal pumps. At each stage in the centrifugal pump, the fluid is directed to towards the centre. This makes it more efficient in operating a large oil field.

3. If we lower the temperature, the water pump cavitation ________
a) Increases
b) Decreases
c) Same
d) Independent

View Answer

Answer: b [Reason:] If we lower the temperature, the water pump cavitation decreases. This happens as the NPSH value reaches a safety margin.

4. Which among the following is not a centrifugal pump?
a) Sand pumps
b) Froth pumps
c) Slurry pumps
d) Energy pumps

View Answer

Answer: d [Reason:] From the above, Energy pumps are not a type of centrifugal pump. At each stage in the centrifugal pump, the fluid is directed to towards the centre. The energy usage in pumping installation is determined by Friction characteristics. Thus, it is not a suitable option.

5. Centrifugal pumps work under the same principle, but differ in their _______
a) Working
b) Functions
c) Dimensions
d) Impeller

View Answer

Answer: b [Reason:] Centrifugal pumps work under the same principle, but differ in their functions. At each stage in the centrifugal pump, the fluid is directed to towards the centre. The energy usage in pumping installation is determined by Friction characteristics.

6. If we raise the liquid level in the suction vessel, cavitation ______
a) Increases
b) Decreases
c) Same
d) Independent

View Answer

Answer: b [Reason:] If we raise the liquid level in the suction vessel, cavitation decreases. This happens as the NPSH value reaches a safety margin.

7. Magnetic coupled pumps are also called as _________
a) Series pumps
b) Parallel pumps
c) Froth pumps
d) Drive pumps

View Answer

Answer: d [Reason:] Magnetic coupled pumps are also called a magnetic drive pumps. They show a lot of difference in their traditional pumping style. It is connected by means of direct mechanical shaft.

8. Magnetic coupled pumps works via ________
a) Antiferromagnet
b) Drive magnet
c) Pump magnet
d) Ferromagnet

View Answer

Answer: b [Reason:] Magnetic coupled pumps works via drive magnet. Magnetic coupled pumps are also called a magnetic drive pumps. They show a lot of difference in their traditional pumping style. It is connected by means of direct mechanical shaft.

9. When we change the pump, the cavitation ______
a) Increases
b) Decreases
c) Same
d) Independent

View Answer

Answer: b [Reason:] By changing the pump we can decrease the cavitation in the pump by bringing the NPSH value to a safety margin.

10. If we reduce the motor rpm in an impeller, cavitation _______
a) Increases
b) Decreases
c) Same
d) Independent

View Answer

Answer: b [Reason:] If we reduce the motor rpm in an impeller, cavitation decreases. This can be done by setting the NPSH value in the safety limit.

11. Decreasing the diameter of the eye of the impeller, cavitation _________
a) Increases
b) Decreases
c) Same
d) Independent

View Answer

Answer: a [Reason:] Decreasing the diameter of the eye of the impeller, cavitation increases due to deviation from the safety limit.

12. No gland is needed for the centrifugal pump.
a) True
b) False

View Answer

Answer: a [Reason:] No gland is needed for the centrifugal pump. This is because they have no direct connection between the motor shaft and the impeller, so there is not a requirement of gland in pumps.

13. Pump is always supported by bearings.
a) True
b) False

View Answer

Answer: b [Reason:] Pump shaft is not always supported by bearings. Since the pumps have no bearing support. The pumps are provided with a housing. The inner walls of the pump are provided with bushings.

14. If we use an impeller inducer, we can reduce the cavitation in a centrifugal pump.
a) True
b) False

View Answer

Answer: a [Reason:] Yes, If we use an impeller inducer, we can reduce the cavitation in a centrifugal pump by bringing the NPSH value to a safety limit.

15. There will be leakage only if there is ________
a) High pressure
b) High temperature
c) Froths are generated
d) Casing breakage

View Answer

Answer: d [Reason:] Pumps have a major problem called as leakage. This might lead to a lot of losses during product manufacture. Thus, the leakage is mainly due to the breaking of the case. Thus, the correct option is casing breakage.