Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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A pump has a displacement of 1.15  and is driven at 1800
rpm. What is its theoretical flow rate in gpm? a. | 1565  | d. | 7.79  | b. | 2070  | e. | none of these | c. | 8.96  |
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2.
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A pump has a displacement of 55  and is driven at 1800
rpm. What is its theoretical flow rate in lpm? a. | 99000  | d. | 32.72  | b. | 99  | e. | none of these | c. | 30.5  |
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3.
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A new system requires a flow rate of at least 25 gpm. What should the
minimum displacement be to achieve this flow rate if the drive speed will be 1200 rpm?
a. | 20.8  | d. | 4.81  | b. | 30000  | e. | none of these | c. | 9.24  |
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4.
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A new system requires a flow rate of at least 100 lpm. What should the
minimum displacement be to achieve this flow rate if the drive speed will be 1800 rpm?
a. | 0.0556  | d. | 10  | b. | 180000  | e. | none of these | c. | 55.56  |
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5.
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A hydraulic pump has a flow rate of 25 gpm and is rated for a maximum pressure
of 3000 psi. What is the maximum horsepower output of this pump?
a. | 75000 hp | d. | 43.76 hp | b. | 120 hp | e. | none of these | c. | 1.19
hp |
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6.
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A hydraulic pump has a flow rate of 90 lpm and is rated for a maximum pressure
of 15,000 kPa. What is the maximum horsepower output of this pump?
a. | 22.5 kW | d. | 135 kW | b. | 787.63 kW | e. | none of these | c. | 166.67
kW |
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7.
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A hydraulic pump with a displacement of 2.5  is selected
for a system that will operate at a maximum pressure of 5000 psi. What is the required drive
torque? Assume 100% efficiency. a. | 12500 in-lbs | d. | 1989 in-lbs | b. | 2000 in-lbs | e. | not enough information | c. | 54.11
in-lb |
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8.
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A hydraulic pump with a displacement of 15  is selected
for a system that will operate at a maximum pressure of 20000 kPa. What is the required drive
torque? Assume 100% efficiency. a. | 1333.33 Nm | d. | 1333333.33 N m | b. | 47.75 N m | e. | not enough information | c. | 47746.48 N
m |
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9.
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An electric motor drives a pump at 1200 rpm with a torque of 1550 in-lb.
What is the horsepower input to this pump?
a. | 29.51 hp | d. | 0.774 hp | b. | 1.29 hp | e. | Not enough information | c. | 194.76
hp |
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10.
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An electric motor drives a pump at 1200 rpm with a torque of 150 N-m. What
is the power input to this pump?
a. | 8 kW | d. | 2.87 kW | b. | 0.125 kW | e. | Not enough information | c. | 18.85
kW |
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11.
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Use the figure to determine the actual flow rate from this pump at 1200 rpm and
1500 psi.  a. | 8 gpm | c. | 4 gpm | b. | 10 gpm | d. | 25 gpm |
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12.
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Use the figure to determine the volumetric efficiency of this pump at 1800 rpm
and 2000 psi.  a. | 82 % | d. | 99% | b. | 80 % | e. | Not enough information | c. | 95
% |
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13.
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Use the figure to determine the overall efficiency of this pump at 1800 rpm and
2000 psi.  a. | 82 % | d. | 99% | b. | 80 % | e. | Not enough information | c. | 95
% |
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14.
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Use the figure to determine the actural flow rate of this pump at 1800 rpm and
2000 psi. The graph shows 1.2  displacement.  a. | 5.67 gpm | d. | 92 gpm | b. | 8.88 gpm | e. | Not enough information | c. | 82
gpm |
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Completion
Complete each
statement.
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15.
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The __________ mover supplies the input power to the pump.
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16.
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The type of pump used in a hydrostaic system is a _________ displacement
pump.
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17.
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Hydrodynamic systems often use ______________ displacement pumps.
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18.
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The purpose of a pump is to create ___________.
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19.
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The volume of fluid that is discharged per cycle is called the
______________.
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20.
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The flow rate of a pump is the volume of fluid that it outputs per unit time,
also known as the delivery or ________.
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21.
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Pumps are rated by their flow rate and the maximum _________ they can
withstand.
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22.
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Torque is generated whenever a force is applied to ________ a shaft or lever arm
around a pivot point.
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23.
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Volumetric efficiency is the ratio of the actual flow rate to the __________
flow rate.
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24.
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Three types of positive displacement pumps are commonly used in fluid power
systems: piston pumps, gear pumps, and ______ pumps.
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25.
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Piston pumps are the most expensive and the most ___________ of the three types
of pumps.
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26.
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Gear pumps are the _______ efficient of the three pump types.
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27.
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Vane pumps are more efficient than gear pumps, but less efficient than _______
pumps.
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28.
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A pressure-compensated pump has the ability to limit the _________ pressure in a
hydraulic circuit by reducing its displacement.
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29.
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Unidirectional pumps can be rotated in only _________ direction.
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30.
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Cavitation is the formation of oil vapor ________ due to very low pressure (high
vacuum) on the inlet side of the pump.
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31.
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With aeration, the source of the gas bubbles is outside ______ leaking into the
system rather than vapor and air bubbles forming from within the system.
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Matching
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a. | 81 lpm | h. | 842.6 in-lb | b. | 18.28 hp | i. | 49.38  | c. | 28,240 kPa | j. | 2.88  | d. | 92.84
N-m | k. | 25.5
kW | e. | 19.26 gpm | l. | 20.5 hp | f. | 15.43 gpm | m. | 19.16 kW | g. | 4285
psi |
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32.
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A hydraulic power unit (electric motor and pump) produces a flow rate of 8 gpm
and has a maximum power rating of 20 hp. What is the maximum operating pressure of this
unit? Assume 100% efficiency.
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33.
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A hydraulic power unit produces a flow rate of 85 lpm and has a maximum power
rating of 40 kW. What is the maximum operating pressure of this unit? Assume 100%
efficiency.
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34.
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A pump has a displacement of 4.12  and a volumetric efficiency
of 0.90. What will its actual flow rate be if it is driven at 1200 rpm?
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35.
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A pump has a displacement of 75  and a volumetric efficiency
of 0.90. What will its actual flow rate be if it is driven at 1200 rpm?
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36.
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A minimum flow of 15 gpm is required in a new system. The pump type
chosen has a volumetric efficiency of 0.88 and will be diven at 1800 rpm. What is the minimum
displacement required?
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37.
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A pump has a displacement of 2.25  . The pump type chosen
has a volumetric efficiency of 0.88 and will be diven at 1800 rpm. What will the flow rate be with
this pump?
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38.
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A minimum flow of 80 lpm is required in a new system. The pump type
chosen has a volumetric efficiency of 0.90 and will be diven at 1800 rpm. What is the minimum
displacement required?
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39.
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A pump that has an mechanical efficiency of 0.85 and a displacement of 2.25
 is to be used in a system witha maximum
operating pressure of 2000 psi. What is the required drive torque?
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40.
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A pump that has an mechanical efficiency of 0.90 and a displacement of 35  is to be used in a system witha maximum operating pressure of 15,000 kPa. What is
the required drive torque?
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41.
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A pump has an overall efficiency of 0.83 and a flow rate of 13 gpm is to be
used in a system that has a maximum operating pressure of 2000 psi. What is the minimum input
horsepower required?
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42.
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A pump has an overall efficiency of 0.87 and a flow rate of 100 lpm is to be
used in a system that has a maximum operating pressure of 10,000kPa. What is the minimum input
horsepower required?
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43.
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A pump with an overall effiency of 0.82 is connected to an electric motor with
a maximum power rating of 25 hp. What is the maximum hydraulic horsepower output for this
system?
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44.
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A pump with an overall effiency of 0.85 is connected to an electric motor with
a maximum power rating of 30 kw. What is the maximum hydraulic power output for this
system?
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a. | Variable displacement | c. | Fixed displacement | b. | Pressure compensated | d. | Bi-directional |
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45.
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46.
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47.
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48.
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