In fixed displacement vane pump,

flow rate increases with increase in working pressure

flow rate decreases with increase in working pressure

flow rate increases with increase in working pressure

flow rate is constant and does not change with working pressure

What is the function of a flow control valve?

flow control valve changes the direction of oil flow

flow control valve can adjust the flow rate of hydraulic oil

Which stage in two stage direction control valve is solenoid operated?

both stages in two stage direction control are solenoid operated

main stage direction control valve

pilot stage direction control valve

both stages in two stage direction control are solenoid operated

Which of the following statements is/are false?

less power is developed in fluid power systems than conventional systems

mechanical linkages used for load handling purposes have high efficiency

How is pressure of fluid under piston calculated in a weighted accumulator?

pressure of fluid = (piston area / weight added)

pressure of fluid = (weight added / piston area)

pressure of fluid = (piston area / weight added)

pressure of fluid = (weight added / piston force)

pressure of fluid = (piston force / weight added)

The hydraulic system is

both hydraulic and pneumatic systems are same on basis of precision

less precise than pneumatic system

more precise than pneumatic system

both hydraulic and pneumatic systems are same on basis of precision

Which of the following pumps saves more power?

single and double pump use same amount of power

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?

initially to reach a job, a tool must be connected to a pump of low discharge and high pressure

initially to reach a job, a tool must be connected to a pump of high discharge and low pressure

initially to reach a job, a tool must be connected to a pump of low discharge and high pressure

for feeding operation low discharge low pressure pump is required

Where is an intercooler connected in a two stage compressor?

intercooler is connected before the two stage compressor

intercooler is connected after the two stage compressor

intercooler is connected between the two stages of the compressor

intercooler is connected before the two stage compressor

What is the function of unloading relief valve and can it be used as an accessory for accumulators?

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

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 access

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

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

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

What is the difference between signal air and control air?

control air actuates final control valve and signal air flows to the cylinder through the final control valve for forward and backward movement of pis

signal air actuates final control valve and control air flows to the cylinder through the final control valve for forward and backward movement of pis

control air actuates final control valve and signal air flows to the cylinder through the final control valve for forward and backward movement of pis

What is the advantage of PLC?

replacements can be easily made

What is the function of pressure switch?

pressure switch is used to start a motor

pressure switch is used to stop a motor

pressure switch is used to de-energize a solenoid

How is reverse flow possible in pilot operated check valve?

spring force lifts the ball due to which reverse flow is possible

fluid pressure lifts the ball due to which reverse flow is possible

What is the difference between pressure relief valve and pressure reducing valve?

pressure reducing valve is connected between pump and tank line while pressure relief valve is connected between DCV and branch circuit

pressure relief valve is always normally opened

pressure reducing valve is connected between DCV and branch circuit while pressure relief valve is connected between pump and tank

While operating a positive displacement pump,

the shut-off valve should be closed on delivery side

the shut-off valve should be closed on suction side

the shut-off valve should be opened on delivery side

What effect does working pressure have on input power for radial piston pumps?

pressure remains constant for different input powers

as working pressure increases input power decreases

as working pressure increases input power increases

pressure remains constant for different input powers

Radial piston pumps can have,

cylinder block rotating and cam stationary

cylinder block stationary and cam rotating

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?

oil will flow through both the paths simultaneously

oil will flow to the path where load is attached

oil will flow back to the reservoir first

oil will flow through both the paths simultaneously

Why are hydraulic cylinders cushioned?

cushioning decelerates the piston of a cylinder

stress and vibrations can be reduced

If no load is attached to piston rod, the movement of piston assembly is possible when

oil overcomes friction in the piston rod assembly

Why is the pilot operated check valve used in clamping operation?

to reduce leakage in spool valve

to avoid decrease in pressure during clamping

In hydraulic systems,

the electrical energy is transferred to the oil and then converted into mechanical energy

the mechanical energy is transferred to the oil and then converted into mechanical energy

the electrical energy is transferred to the oil and then converted into mechanical energy

the mechanical energy is transferred to the oil and converted into electrical energy

266 + Mcqs in Hydraulics & Pneumatics Test Questions Page 2 McqOptions

51.	In fixed displacement vane pump,
A.	flow rate decreases with increase in working pressure
B.	flow rate increases with increase in working pressure
C.	flow rate is constant and does not change with working pressure
D.	none of the above
Answer» B. flow rate increases with increase in working pressure

52.	Which of the following is a hydraulic cylinder based on construction?
A.	single acting cylinder
B.	double acting cylinder
C.	welded design cylinder
D.	all of the above
Answer» D. all of the above

53.	Which type of solenoid has more chances of coil failure?
A.	AC solenoid
B.	DC solenoid
C.	both AC and DC solenoids
D.	none of the above
Answer» B. DC solenoid

55.	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
Answer» E.

56.	Which of the following statements are true for accumulator used in hydraulic systems? 1. Accumulator stores fluid with pressure 2. Accumulator stores fluid without any pressure 3. Accumulator stores compressible liquid 4. Spring is used as an external source to keep the fluid under hydraulic pressure
A.	1, 3 and 4
B.	2 and 3
C.	1 and 4
D.	2, 3 and 4
Answer» D. 2, 3 and 4

57.	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
Answer» B. 2 and 4

59.	Which of the following is a gas charged accumulator?
A.	bladder type
B.	spring loaded accumulator
C.	weighted accumulator
D.	all of the above
Answer» B. spring loaded accumulator

60.	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
Answer» E.

62.	Which energy is used to transmit power in hydrostatic system?
A.	pressure energy
B.	kinetic energy
C.	potential energy
D.	all of the above
Answer» B. kinetic energy

63.	Which system uses kinetic energy to transmit power?
A.	hydrostatic system
B.	hydrodynamic system
C.	pneumatic system
D.	none of the above
Answer» C. pneumatic system

64.	Pumps used in hydraulic applications are
A.	positive displacement pumps
B.	variable displacement pumps
C.	fixed displacement pumps
D.	all of the above
Answer» E.

73.	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
Answer» C. saturation quantity

66.	Which of the following is used as an accessory in hydraulic power unit?
A.	pumps
B.	valves
C.	motor
D.	reservoir
Answer» E.

67.	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
Answer» E.

68.	Check valve is a type of
A.	pressure reducing valve
B.	pressure relief valve
C.	directional control valve
D.	none of the above
Answer» D. none of the above

69.	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
Answer» D. none of the above

70.	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
Answer» C. single and double pump use same amount of power

75.	What are different operations performed by PLC's?
A.	Boolean logic
B.	Timing
C.	Arithmetic
D.	all of the above
Answer» E.

77.	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
Answer» D. all of the above

78.	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
Answer» D. all of the above

79.	Accumulator used in gas charged accumulator is
A.	hydraulic
B.	pneumatic
C.	hydropneumatic
D.	none of the above
Answer» D. none of the above

80.	A pressure relief valve can be
A.	direct operated
B.	pilot operated
C.	solenoid operated
D.	all of the above
Answer» E.

Explore topic-wise MCQs in Mechanical Engineering Questions.

In fixed displacement vane pump,

Which of the following is a hydraulic cylinder based on construction?

Which type of solenoid has more chances of coil failure?

What is the function of a flow control valve?

In single acting hydraulic cylinders, the piston comes back to its original position due to

Which stage in two stage direction control valve is solenoid operated?

Which of the following is a gas charged accumulator?

Which of the following statements is/are false?

How is pressure of fluid under piston calculated in a weighted accumulator?

Which energy is used to transmit power in hydrostatic system?

Which system uses kinetic energy to transmit power?

Pumps used in hydraulic applications are

The hydraulic system is

Which of the following is used as an accessory in hydraulic power unit?

Which type of pump is used for lifting water from the ground surface to the top of the building?

Check valve is a type of

Cylinder has a bore area of 300 cm 2 and velocity of 180 cm/min. Calculate the flow rate of a pump

Which of the following pumps saves more power?

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?

Where is an intercooler connected in a two stage compressor?

Mass of water vapour in unit volume of air is known as

What is the function of unloading relief valve and can it be used as an accessory for accumulators?

What are different operations performed by PLC's?

What is the difference between signal air and control air?

What is the advantage of PLC?

Accumulator used in gas charged accumulator is

A pressure relief valve can be

Which valve is also known as memory valve?

What is the function of pressure switch?

How is reverse flow possible in pilot operated check valve?

What is the difference between pressure relief valve and pressure reducing valve?

Intensifier used in pneumatic systems has output pressure

While operating a positive displacement pump,

What effect does working pressure have on input power for radial piston pumps?

Radial piston pumps can have,

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?

At low pressures, liquids are

Why are hydraulic cylinders cushioned?

Which of these actions does a hydraulic cylinder perform?

If no load is attached to piston rod, the movement of piston assembly is possible when

If capacity of pump is more, it pumps less oil per unit time.

Which of the following gas is used in gas charged accumulator?

Which factor helps in obtaining high speed of the piston rod in the hydraulic system?

Why is the pilot operated check valve used in clamping operation?

Which of the following notations is used to represent a regulator unit?

In hydraulic systems,

Give significance of every digit used to denote a flow control valve 2.03 A. 3 denotes the forward movement B. 3 denotes the backward movement C. 2 denotes the cylinder number D. 2 denotes the flow control valve number

81.	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
Answer» C. roller lever valve

85.	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
Answer» C. same as input pressure

90.	At low pressures, liquids are
A.	compressible
B.	non-compressible
C.	unpredictable
D.	none of the above
Answer» C. unpredictable

92.	Which of these actions does a hydraulic cylinder perform?
A.	pushing
B.	lifting
C.	both a. and b.
D.	none of the above
Answer» D. none of the above

93.	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
Answer» D. none of the above

94.	If capacity of pump is more, it pumps less oil per unit time.
A.	True
B.	False
Answer» C.

95.	Which of the following gas is used in gas charged accumulator?
A.	oxygen
B.	nitrogen
C.	carbon dioxide
D.	all of the above
Answer» C. carbon dioxide

96.	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
Answer» E.

98.	Which of the following notations is used to represent a regulator unit?
A.	3.0
B.	0.3
C.	3
D.	none of the above
Answer» C. 3

100.	Give significance of every digit used to denote a flow control valve 2.03 A. 3 denotes the forward movement B. 3 denotes the backward movement C. 2 denotes the cylinder number D. 2 denotes the flow control valve number
A.	B and C
B.	A and C
C.	A and D
D.	B and D
Answer» B. A and C