# 250+ TOP MCQs on Hydraulic Actuating Systems – Control Valves and Answers

Mechatronics Multiple Choice Questions on “Hydraulic Actuating Systems – Control Valves”.

1. What is the function of the control valve?
a) To control different parameters of the fluid
b) To perform two operations in sequence
c) To control the direction of flow
d) To avoid the development of excess of pressure
Clarification: The control valve is used to control different parameters of fluid, by which the required specific task is completed in a proper way as desired. The other functions mentioned in the options are the functions of the Direction control valve, Sequence valve and hydraulic fuse respectively.

2. Which among the following fluid parameters are not controlled by the control valves?
a) Pressure
b) Rate of flow
c) Speed
d) Direction of flow
Clarification: Speed is not an important parameter controlled by the control valves. Control valves control the fluid parameters such as the pressure of the working fluid, Rate of flow of working fluid and direction of flow of the working fluid.

3. There is no difference between the control valve of the pneumatic and hydraulic system.
a) True
b) False
Clarification: The only difference between the control valve of the pneumatic and hydraulic system is that the hydraulic components are made stronger and heavy, they are made up of steel as they have to work under very high pressure of oil, Whereas the pneumatic components are made lighter using aluminium, plastic etc.

4. What is the function of the pressure control valve?
a) To control the force generated by actuators
b) To perform two operations in sequence
c) To control the direction of flow
d) To avoid the development of excess of pressure
Clarification: The main function of the pressure control valve is to control the force generated by actuators. The other functions mentioned in the options are the functions of the Direction control valve, Sequence valve and hydraulic fuse respectively. The control valve is used to control different parameters of the fluid.

5. The valve packing of control valves is used ____
a) to prevent the fluid from escaping
b) to control the force generated by actuators
c) to control different parameters of the fluid
d) to control the direction of flow
Clarification: The valve packing of control valves is used to prevent the fluid from escaping. In the other options, the main function of the pressure control valve is to control the force generated by actuators. The control valve is used to control different parameters of fluid by which the required specific task is completed in the proper way as desired.

6. The pressure relief valve is an important component which is required for every positive displacement pump.
a) True
b) False
Clarification: Pressure relief valve is an important component which is required for every positive displacement pump. This valve is connected to the outlet of the pump. Its main function is to release the oil back to the tank when the pressure increases beyond pre-set value.

7. What is the formula of speed control valve during extension of a flow control valve?
a) V=(Q/A)
b) V=Q.A
c) V=A/Q
d) V=Q(A-a)
Clarification: The formula of speed control valve during extension of a flow control valve is V=(Q/A) where ‘Q’ is the rate of flow of the working fluid and A is the area of the Piston. V is the speed of the actuator.

8. What is the formula of speed control valve during retraction of a flow control valve?
a) V=(Q/A)
b) V=Q.A
c) V=A/Q
d) V=Q/(A-a)
Clarification: The formula of speed control valve during retraction of a flow control valve is V=Q/(A-a), where ‘Q’ is the rate of flow of the working fluid and A is the area of the Piston. V is the speed of the actuator and ‘a’ is the area of the piston rod.

9. Which among the following are not the ‘work parameters’ of the fluid?
a) Direction
b) Speed
c) Pressure
d) Temperature of flow