250+ TOP MCQs on Hydraulic Actuating Systems – Pressure Regulation and Answers

Mechatronics Multiple Choice Questions on “Hydraulic Actuating Systems – Pressure Regulation”.

1. What is the function of a 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.

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. Pressure reducing valve is used to maintain constant reduced pressure.
a) True
b) False
Clarification: Pressure reducing valve is used to maintain constant reduced pressure in a system. It consists of a diaphragm, an adjusting screw, a spring, a conical poppet fit to the diaphragm. If the pressure of the outlet increases, the diaphragm deflects upwards due to which the conical poppet will also move upwards to close the passage of working fluid flow.

4. Once the pressure comes to normal, the diaphragm ____
a) deflects downwards
b) deflects upwards
c) has no effect
d) expands
Clarification: Once the pressure comes to normal, the diaphragm deflects downwards. If the pressure of the outlet increases, the diaphragm deflects upwards due to which the conical poppet will also move upwards to close the passage of working fluid flow. At normal pressure, it deflects downwards and the conical poppet moves downwards.

5. The function of the pressure relief valve is ____
a) to open when the inlet pressure is more
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 function of the pressure relief valve is that it opens when the inlet pressure which may be the system pressure or the pilot pressure becomes more than the pre-set value. 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 a 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 function of a pressure gauge?
a) It controls the rate of flow of oil
b) It shows the pressure reading
c) Controls the direction of flow of oil
d) It converts the mechanical energy to hydraulic energy
Clarification: The pressure gauge is used to give the pressure reading. Pressure settings are made into the pressure gauge. Without a pressure gauge, it is not possible to make the pressure relief valve settings, unloading valve settings etc.

8. What happens when the pressure increases its pre-set value?
a) The pressure relief valve opens
b) Deflects upwards
c) Deflects downwards
d) Has no effect
Clarification: If the pressure inside a system increases above the pre-set level, this valve opens to release the working fluid back to the reservoir tank, so that the system pressure comes to the normal value. The other mentioned options are not the correct choices.

9. What is the formula for the force of a cylinder?
a) F=(p*a)
b) F=(p+a)
c) F=(p/a)
d) F=(p/ap)