# Hydraulics and Pneumatics 5

Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Hydraulics and Pneumatics 5

Part 5: List for questions and answers of Hydraulics and Pneumatics

Q1.A pressure relief valve can be
a) Direct operated
b) Pilot operated
c) Solenoid operated
d) All the above

Q2.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

Q3. Why are bleed off circuits used?
a) Bleed off circuit is used to restrict the flow of fluid into the hydraulic cylinder
b) Bleed off circuit is used to restrict the flow of fluid out of the hydraulic cylinder
c) Bleed off circuits are used to reduce the speed of actuator
d) All the above

Q4. Which of the following is applicable for bleed off circuits?
a) Bleed off circuits develop heat in the system
b) Bleed off circuits are used for resistive loads
c) Bleed off circuits are used for runaway loads
d) All the above

Q5. What is the function of sequence valve used in hydraulic circuits?
a) Sequence valves are used to perform number of operations one after the other after the set pressure is reached
b) Sequence valves are used to perform number of operations continuously before the
set pressure is reached
c) Sequence valves after reaching set pressure oil is flown to the tank
d) All the above

Q6.When is a pressure reducing valve used?
a) It is used when higher pressure than system pressure is required
b) It is used when lower pressure than system pressure is required
c) When absolutely zero pressure is required
d) All the above

Q7.One litre of water occupies a volume of
a) 100 cm^3
b) 250 cm^3
c) 500 cm^3
d) 1000 cm^3

Q8.In one dimensional flow, the flow
b) Takes place in straight line
c) Takes place in curve
d) Takes place in one direction

Q9.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

Q10. Which of the following logic valve is known as shuttle valve?
a) OR gate
b) AND gate
c) NOR gate
d) NAND

Q11. In pneumatic systems, AND gate is also known as
a) Check valve
b) Shuttle valve
c) Dual pressure valve
d) None of the above

Q12.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 the above

Q13. 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

Q14. 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

Q15. 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

Q16. Overlapping of signals in pneumatic systems can be avoided by using
a) Rolling lever valve
b) Idle roller lever valve
c) Both a and b
d) None of the above

Q17. How is proximity switch differentiated from limit switch?
a) Proximity switch is activated when moving parts have physical contact with it
b) Proximity switch is activated when non-moving parts have physical contact
c) Proximity switch is activated when moving parts are close to it
d) None of the above

Q18. In which circuits, relay of low voltage and low current is used to make open or close contact?
a) High voltage and high current circuit
b) Low voltage and low current circuit
c) High voltage and low current circuit
d) Low voltage and low current circuit

Q19. In electro pneumatic circuits
a) Spool is shifted by signal air
b) Spool is shifted by control air
c) Spool is shifted by electromotive force
d) All the above

Q20. Why are electromechanical relays more popular than solid state relays?
a) They are reliable
b) Less costly
c) Both a and b
d) None of the above

Part 5: List for questions and answers of Hydraulics and Pneumatics