1) In which systems, spool of the servo valve is operated by a torque motor?
a. hydromechanical servo systems
b. electrohydraulic servo systems
c. conventional servo valve
d. all of the above
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2) What does servo mean in servo valve system?
a. it cannot receive a feedback but the desired output can be obtained
b. it cannot receive a feedback and the desired output cannot be obtained
c. it can receive a feedback and the desired output can be obtained
d. none of the above
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Answer
Explanation
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ANSWER: it can receive a feedback and the desired output can be obtained
Explanation:
No explanation is available for this question!
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3) In conventional valves, which component is used to move the spool?
a. torque motor
b. mechanical servo valve
c. solenoid
d. all of the above
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4) What is the advantage of DC solenoid coils?
a. DC solenoid coils have high rush in current
b. DC solenoid coils have constant level of current
c. DC solenoid coils have rating of 220 V DC
d. all of the above
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Answer
Explanation
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ANSWER: DC solenoid coils have constant level of current
Explanation:
No explanation is available for this question!
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5) Which of the following statements is true for a proportional valve?
a. spool of the proportional valve can travel maximum length
b. digital type of functioning is possible in proportional valve
c. proportional valve requires a separate flow control valve
d. all of the above
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Answer
Explanation
Related Ques
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ANSWER: spool of the proportional valve can travel maximum length
Explanation:
No explanation is available for this question!
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6) Which of the following statements is/are false?
a. air is non-compressible
b. less power is developed in fluid power systems than conventional systems
c. mechanical linkages used for load handling purposes have high efficiency
d. all of the above
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7) How is tilting action possible in trucks for unloading the gravel material using hydraulic power?
1. Tilting action is possible if, oil flows at high pressure into the cylinder
2. Tilting action is possible if, air flows at low pressure into the cylinder
3. The truck body tilts when piston rod in the actuator is pushed out.
4. Tilting action is possible if air is compressed at high pressure
a. 1 and 3
b. 2 and 4
c. 3 and 4
d. none of the above
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8) The hydraulic system is
a. less precise than pneumatic system
b. more precise than pneumatic system
c. both hydraulic and pneumatic systems are same on basis of precision
d. none of the above
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9) Which energy is used to transmit power in hydrostatic system?
a. pressure energy
b. kinetic energy
c. potential energy
d. all of the above
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10) Which system uses kinetic energy to transmit power?
a. hydrostatic system
b. hydrodynamic system
c. pneumatic system
d. none of the above
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11) If no load is attached to piston rod, the movement of piston assembly is possible when
a. oil overcomes its self weight
b. oil overcomes friction in the piston rod assembly
c. both a. and b.
d. none of the above
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12) If capacity of pump is more, it pumps less oil per unit time.
a. True
b. False
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13) Which factor helps in obtaining high speed of the piston rod in the hydraulic system?
a. decreased friction
b. pump capacity
c. increased flow rate
d. all of the above
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14) During any operation in hydraulic system, oil prefers the path of
a. least resistance
b. maximum resistance
c. both a. and b.
d. none of the above
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15) In a hydraulic circuit a pump is provided with two outlet paths, one where load is attached and other to the reservoir. Which path will the oil choose to flow first?
a. oil will flow to the path where load is attached
b. oil will flow back to the reservoir first
c. oil will flow through both the paths simultaneously
d. none of the above
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16) Which of the following is used as an accessory in hydraulic power unit?
a. pumps
b. valves
c. motor
d. reservoir
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17) Which type of pump is used for lifting water from the ground surface to the top of the building?
a. centrifugal pump
b. turbine pump
c. submersible pump
d. all of the above
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18) Pumps used in hydraulic applications are
a. positive displacement pumps
b. variable displacement pumps
c. fixed displacement pumps
d. all of the above
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19) What is a positive displacement pump?
a. oil from suction side of the pump flows completely to the delivery side
b. volume of fluid discharged cannot return back to the suction side of the pump
c. discharges fixed volume of fluid every cycle
d. all of the above
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20) While operating a positive displacement pump,
a. the shut-off valve should be closed on delivery side
b. the shut-off valve should be closed on suction side
c. the shut-off valve should be opened on delivery side
d. none of the above
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Answer
Explanation
Related Ques
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ANSWER: the shut-off valve should be opened on delivery side
Explanation:
No explanation is available for this question!
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21) What effect does working pressure have on input power for radial piston pumps?
a. as working pressure increases input power decreases
b. as working pressure increases input power increases
c. pressure remains constant for different input powers
d. none of the above
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Answer
Explanation
Related Ques
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ANSWER: as working pressure increases input power increases
Explanation:
No explanation is available for this question!
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22) Radial piston pumps can have,
a. cylinder block rotating and cam stationary
b. cylinder block stationary and cam rotating
c. both a. and b.
d. none of the above
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23) Why are hydraulic cylinders cushioned?
a. cushioning decelerates the piston of a cylinder
b. stress and vibrations can be reduced
c. both a. and b.
d. none of the above
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24) Which of the following statements is true?
a. Tie-rod cylinders are used in applications having working pressure of 70 bar
b. Welded type cylinders are used in systems having working pressure more than 70 bar
c. Tie-rod cylinders can be used in systems having working pressure more than 70 bar
d. all of the above
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25) Which of these actions does a hydraulic cylinder perform?
a. pushing
b. lifting
c. both a. and b.
d. none of the above
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26) Leakage in welded type of hydraulic cylinder is prevented by
a. wiper in gland cover
b. rod seal in end cover
c. rod seal in gland cover
d. none of the above
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27) In single acting hydraulic cylinders, the piston comes back to its original position due to
a. spring force
b. self-weight
c. momentum of a flywheel
d. all of the above
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28) Check valve is a type of
a. pressure reducing valve
b. pressure relief valve
c. directional control valve
d. none of the above
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29) A pressure relief valve can be
a. direct operated
b. pilot operated
c. solenoid operated
d. all of the above
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30) Which of the following statements are true for throttle valve?
1. Reverse flow of fluid is not possible
2. Input pressure for a throttle valve is more than output pressure
3. The actuator speed can be reduced by a throttle valve
4. Correct flow control valve for a particular application can be selected on the basis of pressure drop specified
a. 1, 2 and 3
b. 1, 3 and 4
c. 2, 3 and 4
d. all of the above
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31) How is reverse flow possible in pilot operated check valve?
a. spring force lifts the ball due to which reverse flow is possible
b. fluid pressure lifts the ball due to which reverse flow is possible
c. both a. and b.
d. none of the above
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Answer
Explanation
Related Ques
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ANSWER: fluid pressure lifts the ball due to which reverse flow is possible
Explanation:
No explanation is available for this question!
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32) What is the difference between pressure relief valve and pressure reducing valve?
a. pressure reducing valve is connected between pump and tank line while pressure relief valve is connected between DCV and branch circuit
b. pressure relief valve is always normally opened
c. pressure reducing valve is connected between DCV and branch circuit while pressure relief valve is connected between pump and tank
d. none of the above
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Answer
Explanation
Related Ques
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ANSWER: pressure reducing valve is connected between DCV and branch circuit while pressure relief valve is connected between pump and tank
Explanation:
No explanation is available for this question!
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33) Accumulator used in gas charged accumulator is
a. hydraulic
b. pneumatic
c. hydropneumatic
d. none of the above
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34) What is the function of pressure switch?
a. pressure switch is used to start a motor
b. pressure switch is used to stop a motor
c. pressure switch is used to de-energize a solenoid
d. all of the above
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35) Intensifier used in pneumatic systems has output pressure
a. less than input pressure
b. more than input pressure
c. same as input pressure
d. none of the above
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36) What is the function of unloading relief valve and can it be used as an accessory for accumulators?
a. unloading relief valve is used to charge the accumulator by a pump when accumulator pressure falls below the set value and it can be used as an accessory.
b. unloading relief valve is used to charge the accumulator by a pump when accumulator pressure falls below the set value but is not used as an accessory
c. unloading relief valve is used to charge the accumulator by a pump when accumulator pressure rises above the set value but is not used as an accessory
d. unloading relief valve is used to charge the accumulator by a pump when accumulator pressure rises above the set value and is used as an accessory
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Answer
Explanation
Related Ques
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ANSWER: unloading relief valve is used to charge the accumulator by a pump when accumulator pressure falls below the set value and it can be used as an accessory.
Explanation:
No explanation is available for this question!
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37) Cylinder has a bore area of 300 cm 2 and velocity of 180 cm/min. Calculate the flow rate of a pump
a. 55 l/min
b. 50 l/min
c. 54 l/min
d. none of the above
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38) Which of the following statements is true, for two pumps used in circuit when initially fast operation is performed to reach a job and feeding operation is done at a slow speed?
a. initially to reach a job, a tool must be connected to a pump of high discharge and low pressure
b. initially to reach a job, a tool must be connected to a pump of low discharge and high pressure
c. for feeding operation low discharge low pressure pump is required
d. none of the above
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Answer
Explanation
Related Ques
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ANSWER: initially to reach a job, a tool must be connected to a pump of high discharge and low pressure
Explanation:
No explanation is available for this question!
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39) What are different operations performed by PLC's?
a. Boolean logic
b. Timing
c. Arithmetic
d. all of the above
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40) Which of the following pumps saves more power?
a. single pump
b. double pump
c. single and double pump use same amount of power
d. none of the above
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41) What is the advantage of PLC?
a. easy to find errors
b. replacements can be easily made
c. PLC's are easily programmed
d. all of the above
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42) What is difference between regulator and pressure switch?
a. regulator operates at set value pressure while pressure switch operates with slight fluctuation in pressure
b. pressure switch operates at set value pressure while regulator operates with slight fluctuation in pressure
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Answer
Explanation
Related Ques
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ANSWER: regulator operates at set value pressure while pressure switch operates with slight fluctuation in pressure
Explanation:
No explanation is available for this question!
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43) Mass of water vapour in unit volume of air is known as
a. relative humidity
b. absolute humidity
c. saturation quantity
d. none of the above
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44) Which valve is also known as memory valve?
a. single pilot signal valve
b. double pilot signal valve
c. roller lever valve
d. logic valve
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45) What is the difference between signal air and control air?
a. signal air actuates final control valve and control air flows to the cylinder through the final control valve for forward and backward movement of piston rod
b. control air actuates final control valve and signal air flows to the cylinder through the final control valve for forward and backward movement of piston rod
c. both a. and b.
d. none of the above
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Answer
Explanation
Related Ques
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ANSWER: signal air actuates final control valve and control air flows to the cylinder through the final control valve for forward and backward movement of piston rod
Explanation:
No explanation is available for this question!
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46) Which of the following is used to sense the initial and final positions of a piston rod?
a. lever operated direction control valve
b. limit switch
c. roller lever valve
d. all of the above
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47) Which valve gets activated only in one direction that is forward or backward movement of the piston rod?
a. roller lever valve
b. idle roller lever valve
c. both a. and b.
d. none of the above
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48) Which numbers are used to denote retraction of a piston rod?
a. even numbers
b. odd numbers
c. both even and odd numbers
d. none of the above
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49) Which of the following is an element of time delay valve?
a. flow control valve
b. direction control valve
c. both a. and b.
d. none of the above
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50) Which of the following is a type of cushioning in hydraulic cylinders?
a. trunnion cushioning
b. adjustable cushioning
c. clevis cushioning
d. none of the above
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