ArulmiguMeenakshi Amman College of Engineering
Vadamavandal-604410.
Impotant questions and answers
HYDRAULICS AND PNEUMATICS
Prepared by
V.Umapathy,
Prof. /Mech.
S.No. Questions and answers
Unit-I
FLUID POWER PRINICIPLES AND HYDRAULIC PUMPS
2 – marks question and answers
1. Define hydraulic.
Hydraulics is a mechanical function that operates through the force of liquid pressure. In hydraulics-
based systems, mechanical movement is produced by contained, pumped liquid, typically through
hydraulic cylinders moving pistons.
2. What is the simple definition of Pascal's law?
Pascal's law says that pressure applied to an enclosed fluid will be transmitted without a change in
magnitude to every point of the fluid and to the walls of the container. The pressure at any point in the
fluid is equal in all directions.
3. What is the meaning of positive displacement pump?
Positive displacement pumps add energy to a fluid by applying force to the liquid with a mechanical
device such as a piston or plunger. A positive displacement pump decreases the volume containing the
liquid until the resulting liquid pressure equals the pressure in the discharge system.
4. Differentiate oil hydraulics and pneumatics.
Pneumatics provides fluid power by means of pressurised air or gases.Hydraulics provides fluid
, power by means of pressurised liquids, such as oil or water. In choosing one of the two, cost-
effectiveness, materials to be moved, availability of resources and space are all factors to be considered.
5. Point out the applications of fluid power.
1. Material Handling. 2. Aircraft Ground Support. 3. Access Platforms. 4. Security & Parking Barriers.5.
Marine. 6. Disability Lifts.7. Mining & Construction.8. Light Industrial..9. Agriculture. 10. Motor
Sports. 11. Leisure & Entertainment. 12. Waste Management.
6. State the effects of high and low viscosity hydraulic fluids in the fluid power system.
When a hydraulic oil is too thick (high viscosity), the fluid will be more difficult to pump through the
system and may reduce operating efficiency.
If the hydraulic fluid viscosity is too low, the oil film will be too thin causing direct metal to metal contact
which leads to excessive wear on components. Low viscosity fluids also increase the risk of internal
leakages generating a lower volumetric efficiency of pumps and motors.
7. What are the selection criteria for a hydraulic pump?
Before you can select a pump that will fit your needs, you must know four things: 1) the total head or
pressure against which it must operate, 2) the desired flow rate, 3) the suction lift, and 4)
characteristics of the fluid.
8. What type of power source is used for hydraulic power?
A hydraulic pump is the power source of a hydraulic system and requires a prime mover, such as a motor
or engine, in order to create fluid flow.
9. What are the 5 types of fluid?
The different types of fluid are: Ideaf fluid, Real fluid, Newtonian fluid, Non-Newtonian fluid,
Incompressible fluid, and Compressible fluid.
10. What is the meaning of demulsibility?
Demulsibility is the ability of oil to separate from water. Oil and water naturally separate because like
molecules attract each other. Oil sticks with oil, water sticks with water. Oil is "hydrophobic", or "afraid of
water," which is a benefit when it comes to fluids like turbine oil.
13 and 15 marks question and answers
11. Explain the elements of hydraulic system with a line sketch.
,
,
Vadamavandal-604410.
Impotant questions and answers
HYDRAULICS AND PNEUMATICS
Prepared by
V.Umapathy,
Prof. /Mech.
S.No. Questions and answers
Unit-I
FLUID POWER PRINICIPLES AND HYDRAULIC PUMPS
2 – marks question and answers
1. Define hydraulic.
Hydraulics is a mechanical function that operates through the force of liquid pressure. In hydraulics-
based systems, mechanical movement is produced by contained, pumped liquid, typically through
hydraulic cylinders moving pistons.
2. What is the simple definition of Pascal's law?
Pascal's law says that pressure applied to an enclosed fluid will be transmitted without a change in
magnitude to every point of the fluid and to the walls of the container. The pressure at any point in the
fluid is equal in all directions.
3. What is the meaning of positive displacement pump?
Positive displacement pumps add energy to a fluid by applying force to the liquid with a mechanical
device such as a piston or plunger. A positive displacement pump decreases the volume containing the
liquid until the resulting liquid pressure equals the pressure in the discharge system.
4. Differentiate oil hydraulics and pneumatics.
Pneumatics provides fluid power by means of pressurised air or gases.Hydraulics provides fluid
, power by means of pressurised liquids, such as oil or water. In choosing one of the two, cost-
effectiveness, materials to be moved, availability of resources and space are all factors to be considered.
5. Point out the applications of fluid power.
1. Material Handling. 2. Aircraft Ground Support. 3. Access Platforms. 4. Security & Parking Barriers.5.
Marine. 6. Disability Lifts.7. Mining & Construction.8. Light Industrial..9. Agriculture. 10. Motor
Sports. 11. Leisure & Entertainment. 12. Waste Management.
6. State the effects of high and low viscosity hydraulic fluids in the fluid power system.
When a hydraulic oil is too thick (high viscosity), the fluid will be more difficult to pump through the
system and may reduce operating efficiency.
If the hydraulic fluid viscosity is too low, the oil film will be too thin causing direct metal to metal contact
which leads to excessive wear on components. Low viscosity fluids also increase the risk of internal
leakages generating a lower volumetric efficiency of pumps and motors.
7. What are the selection criteria for a hydraulic pump?
Before you can select a pump that will fit your needs, you must know four things: 1) the total head or
pressure against which it must operate, 2) the desired flow rate, 3) the suction lift, and 4)
characteristics of the fluid.
8. What type of power source is used for hydraulic power?
A hydraulic pump is the power source of a hydraulic system and requires a prime mover, such as a motor
or engine, in order to create fluid flow.
9. What are the 5 types of fluid?
The different types of fluid are: Ideaf fluid, Real fluid, Newtonian fluid, Non-Newtonian fluid,
Incompressible fluid, and Compressible fluid.
10. What is the meaning of demulsibility?
Demulsibility is the ability of oil to separate from water. Oil and water naturally separate because like
molecules attract each other. Oil sticks with oil, water sticks with water. Oil is "hydrophobic", or "afraid of
water," which is a benefit when it comes to fluids like turbine oil.
13 and 15 marks question and answers
11. Explain the elements of hydraulic system with a line sketch.
,
,
