Hydraulics and Pneumatics mcq questions

Q. 1. Identify the circuit

A : Meter-in -both directions
B : Meter-out- both directions
C : Bleed off- in extension
D : Bleed off in both directions

Bleed off- in extension

Q. 2. Which of the following gas is used in gas charged accumulator?

A : oxygen
B : nitrogen
C : carbon dioxide
D : all of the above

nitrogen

Q. 3. Rotary motion in a hydraulic power unit is achieved by using

A : hydraulic cylinder
B : pneumatic cylinder
C : hydraulic motor
D : limited rotery actuator

hydraulic motor

Q. 4. Port A and Port B is closed and port P is connected to port T. This center position is

A : closed center
B : open center
C : tandem center
D : float center

tandem center

Q. 5. Identify the circuit

A : Counter balance
C : Fast slow circuit
D : High Low circuit

Q. 6. Intake filter is located at

A : before pump
B : after pump
C : return line
D : after DCV

before pump

Q. 7. What do you mean by Fluid Power System

A : Transmission of Power by Means of Liquids and Gasses
B : Transmission of Power by means of Belt, Pulley and Gears
C : Transmission of Power by means of liquids only
D : Transmission of power by means of Gasses only

Transmission of Power by Means of Liquids and Gasses

Q. 8. Check Valves are also called as

A : non-return valve
C : high pressure valve
D : none of the above

non-return valve

Q. 9. The function of the check valve is

A : to control the pressure in only one direction
B : to control the flow in only one direction
C : to allow the flow in only one direction
D : to block the flow in both directions

to allow the flow in only one direction

Q. 10. Vane Pump is type of

A : Positive Displacement
B : Hydrodynamic
C : Rotary Positive Displacement
D : Hydrostatics

Rotary Positive Displacement

Q. 11. Pascal’s law states that pressure in a confined body will act .- – – – in all directions.

B : Erratically
C : Equally
D : Sequentially

Equally

Q. 12. Identify the circuit

A : Meter-In
B : Meter-Out
C : Regenerative circuit
D : Bleed off

Regenerative circuit

Q. 13. Cam lobe hydraulic motor is a type of

A : axial hydraulic motor
B : orbit hydraulic motor
C : gear hydraulic motor

gear hydraulic motor

Q. 14. In 4/3 position DCV which of the component is not present

A : strainer
B : Seals
C : Valve Body
D : Spool

strainer

Q. 15. Identify the circuit

A : Meter-in -extension
B : Meter-in – Retraction
C : Meter-out- extension
D : Meter-out -retraction

Meter-out- extension

Q. 16. Which of the following is a gas charged accumulator?

C : weighted accumulator
D : spring and weight loaded

Q. 17. Pressure relief valve opens when

A : force due to fluid pressure is positive.
B : Spring force is positive
C : spring force is more than fluid pressure force on the poppet
D : spring force is less than fluid pressure force on the poppet

spring force is less than fluid pressure force on the poppet

Q. 18. Pressure drop across a filter can be in the range of

A : 0.5bar
B : 5bar
C : 50bar
D : 500bar

0.5bar

Q. 19. Which type of motion is transmitted by hydraulic actuators?

A : linear motion
B : rotary motion
C : limited rotary motion
D : linear, rotary and limited rotary motion

linear, rotary and limited rotary motion

Q. 20. Where is Pump located in hydraulic system

A : In between DCV and Cylinder
B : In Between Filter and DCV
C : In between Reservoir and filetr
D : In between DCV and rod side of cylinder

In Between Filter and DCV

Q. 21. Which type of hydraulic cylinder has one piston connected to piston rod extended on
both the sides of the cylinder?

A : telescopic cylinder
B : tandem cylinder
C : single acting cylinder
D : double acting cylinder

tandem cylinder

Q. 22. The name of the valve used to maintain control of a vertical cylinder to prevent it from
descending due to gravity is

A : counter balance valve
C : pressure reducing valve
D : prefill valve

counter balance valve

Q. 23. Identify the given symbol

A : 4/3 Solenoid Operated DCV
B : 4/2 Solenoid Operated DCV
C : 4/2 Pilot Operated DCV
D : 5/2 Solenoid Operated DCV

4/2 Solenoid Operated DCV

Q. 24. Inlet and return lines should:

A : terminate below fluid level.
B : terminate above fluid level.
C : terminate above fluid level near top.
D : terminate below fluid level near bottom

terminate below fluid level.

Q. 25. A ________ is a storage reservoir under pressure where a liquid is held under pressure.

A : hydraulic accumulator
B : hydraulic crane
C : hydraulic gear
D : hydraulic pump

hydraulic accumulator

Q. 26. Pressure reducing valve is used to maintain the reduced pressure

A : throughout the system
B : at the outlet of the valve
C : at the inlet of the valve
D : inside the valve

at the outlet of the valve

Q. 27. A hydraulic reservoir is normally sized at:

A : 1 to 2 times pump flow in lit/min.
B : 2 to 3 times pump flow in lit/min.
C : 4 to 6 times pump flow in lit/min.
D : 5 to 7 times pump flow in lit/min.

2 to 3 times pump flow in lit/min.

A : on internal pilot signal
B : on external pilot signal
C : without pilot signal
D : necessarily on more than one pilot signal

on external pilot signal

Q. 29. Motors used in high speed applications have.

A : high torque with high speed
B : low torque with high speed
C : high torque with low speed
D : medium torque with low speed

low torque with high speed

Q. 30. The pump 2 is called

A : Tandem
B : Float
C : Booster
D : Supporting

Booster

Q. 31. Elastomeric prticles are generated from

B : swarf
C : sand
D : seals

seals

Q. 32. Which system would be used for punching operation

A : Hydraulic
B : Electro-Pneumatic
C : Mechanical
D : Hydro-pneumatic

Hydraulic

Q. 33. Clogging of suction filter

A : cloggs DVC valve
B : increases load on pump
C : makes cylinder sticky
D : Cloggs Relief valve

Q. 34. Two stage (Pilot operated) pressure relief valve is preferred over direct acting pressure
relief valve when

A : pump flow rate is small
B : pump flow rate is high
C : pressure override is very large
D : pressure override is very low

pressure override is very low

Q. 35. When do you prefer the pneumatic system rather than hydraulic system?

A : Medium amount of pressure requires speed, fairly accurate feed.
B : Large amount of pressure requires speed, fairly accurate feed.
C : Large amount of pressure requires less speed, fairly accurate feed
D : Medium amount of pressure requires speed, accurate feed

Medium amount of pressure requires speed, fairly accurate feed.

Q. 36. What happens when the distance between flange and cylinder block is varied?

A : piston displacement cannot be varied
B : variable flow rate of fluid can be achieved
C : fixed flow rate can be achieved
D : pressure cannot be varied

variable flow rate of fluid can be achieved

Q. 37. What is the maximum angle between cylinder block and shaft axis?

A : 30^o
B : 50^o
C : 45^o
D : 60^o

30^o

Q. 38. Identify the given symbol

A : Heater
B : Lubricator
C : Cooler
D : Filter

Lubricator

Q. 39. The working of which of the following hydraulic units is based on Pascal’s law?

A : Airlift pump
B : Jet pump
C : Hydraulic coupling
D : Hydraulic press

Hydraulic press

Q. 40. Pressure filter is located at

A : before pump
B : after pump
C : return line
D : after DCV

after pump

Q. 41. Pressure compensated flow control valve

A : controls both pressure and flow in the system
B : increases pressure in the system and maintains flow constant
C : decreases pressure in the system and maintains flow constant
D : maintains flow constant irrespective of change in system pressure

maintains flow constant irrespective of change in system pressure

Q. 42. The valve Z will open at

A : 50.5bar
B : 49 bar
C : 100.5bar
D : 99bar

50.5bar

Q. 43. When DCV is in position R then

A : Low pressure oil passes through path QDAT
B : Low pressure oil passes through path QCDAT
C : Low pressure oil passes through path QDBT
D : Low pressure oil passes through path QDPBT

Low pressure oil passes through path QCDAT

Q. 44. 1 LPM is equal to ——– M^3/sec

A : 1.66*10^-5
B : 1.66*10^-3
C : 1.66*10^5
D : 1.66*10^3

1.66*10^-5

Q. 45. Which of the following is not method of actuation

A : hand lever operated
B : pneumatically operated
C : chemically operated
D : electrically operated

chemically operated

Q. 46. When the DCV is not actuated and road is loaded thenâ€¦

A : The piston will not move at all
B : The piston will move in left direction only
C : The piston will move in right direc
D : The piston will move freely

The piston will move freely

Q. 47. When piston moves to extreme right

A : Main DCV is in R position & Pilot line Y recives signal
B : Main DCV is in R position & Pilot line X recives signal
C : Main DCV is in L position & Pilot line Y recives signal
D : Main DCV is in L position & Pilot line X recives signal

Main DCV is in L position & Pilot line Y recives signal

Q. 48. The given formula defined which type of hydraulic loss in hydraulic system

A : Frictional losses
B : Loss due to bend
C : loss due to fitting
D : loss due to sudden enelargement

rictional losses

Q. 49. Which of the following is a type of low-torque high-speed motor?

B : axial piston motors
C : bent axis motor
D : gear motor

gear motor

Q. 50. Low-torque high-speed motors are used in

A : cranes
B : winches
C : fans
D : lifts

fans

Q. 51. A Pump has an mechanical efficiency of 0.92 and a displacement of 0.00002 m2/rev is to
be used in a system with a maximum operating pressure of 15,000 kPa. What is the required
drive torque?

A : 47.75 Nm
B : 51.90 Nm
C : 74.75 Nm
D : 57.74 Nm

51.90 Nm

Q. 52. A Pump that has an overall efficiency of 0.87 and a flow rate of 45 lit/min is to be used
in a system that has a maximum operating pressure of 25,000 kPa. What input power is
required?

A : 18.75 kW
B : 21.55 kW
C : 55.21 kW
D : 75.18 kW

21.55 kW

Q. 53. Identify the circuit

A : Pump breaking circuit
B : Motor breaking circuit

Motor breaking circuit

Q. 54. Which center position is preferred for a hydraulic motor

A : open center
B : closed center
C : tandem center
D : float center

float center

Q. 55. Pressure Override is

A : Cracking Pressure – Full flow Pressure
B : Full flow Pressure – Cracking Pressure
C : Full flow Pressure /Cracking Pressure
D : Full flow Pressure * Cracking Pressure

Full flow Pressure – Cracking Pressure

Q. 56. How does cushioning affect the speed of the piston when the cylinder is cushioned at
extreme end?

A : cushioning decreases the speed of piston near the extreme ends of the cylinder
B : cushioning increases the speed of piston near the extreme ends of the cylinder
C : cushioning increases the speed of piston at the beginning of the stroke in the cylinder
D : cushioning decreases the speed of piston at the beginning of the stroke in the cylinder

cushioning decreases the speed of piston near the extreme ends of the cylinder

Q. 57. In the circuit given, oil flows through C1 when

A : 4/3 DCV is in position I in , extension of cylinder
B : 4/3 DCV is in position II in , extension of cylinder
C : 4/3 DCV is in position I in , retraction of cylinder
D : 4/3 DCV is in position II in , retraction of cylinder

4/3 DCV is in position II in , retraction of cylinder

Q. 58. if 100000N force is applied on 100 sq.cm area the pressure setting in relief valve will be
around

A : 10 bar
B : 100 bar
C : 1000 bar
D : 1000000 bar

100 bar

Q. 59. A hydraulic intensifier normally consists of

A : two cylinders, two rams and a storage device
B : a cylinder and a ram
C : two co-axial rams and two cylinders
D : a cylinder, a piston, storage tank and control valve

two co-axial rams and two cylinders

Q. 60. The Y port on a solenoid pilot-operated valve is for

A : internal drain
B : external drain
C : internal pilot
D : external pilot