Hydraulics Quiz 1

The difference between an unbalanced vane pump and a balanced vane pump is the

direction of rotation.

type of oil used.

inlet and outlet vanes.

number of inlet and outlet ports.

Correct! Wrong!

Cavitation could occur when

engine speed is too low.

system pressure is adjusted too high.

return line filters are plugged.

oil viscosity is too high.

Correct! Wrong!

An open center hydraulic system can best be described as one in which

pump oil flow is not circulated until a demand is imposed with operator controls.

pump oil flow recirculates freely to the reservoir with controls in the neutral position.

pump oil flow is not unloaded to the reservoir in the neutral position.

the hydraulic storage tank does not have filters inside the tank.

Correct! Wrong!

A four connection (four way) spool valve is used in conjunction with a

double acting cylinder.

single acting cylinder.

telescoping ram.

ram type cylinder.

Correct! Wrong!

In the illustration below, what type of hydraulic system is being illustrated?

an open center system.

a closed center system.

a non-positive displacement system.

a fixed displacement system.

Correct! Wrong!

Viscosity of a liquid can best be described as

a small fluctuation of fluid pressures.

a small amount of fluid flow.

the velocity of fluid flow.

the resistance to fluid flow.

Correct! Wrong!

The oil inlet hole size of a hydraulic pump should

match the driven end of the pump.

be larger than the outlet.

be smaller than the outlet.

have different style threads or fittings than the outlet.

Correct! Wrong!

have different style threads or fittings than the outlet.

system output pressure times the piston area.

system output pressure times the cylinder piston travel.

system output volume times the piston area.

system output volume times the cylinder piston travel.

Correct! Wrong!

Hydraulic hose #SAE100R2AT-8 purchased from a supplier is marked for application. The -8 number used for sizing hydraulic hose refers to its inner diameter in

8ths of an inch.

16ths of an inch.

number of wraps of braid.

type of rubber used for hydraulics use.

Correct! Wrong!

To evaluate a hydraulics system, when flow and pressure testing a piece of equipment, the flow rate is best defined as

a measure of the volume of fluid that passes a given point in a given time.

a measure of the speed of fluid that passes a given point in a given time.

the average speed of a fluid past a given point.

a rating of the viscosity of hydraulic oil while in motion past a given point.

Correct! Wrong!

In a system with a variable displacement pump, the volume of the fluid moved by the pump will

decrease when the system pressure drops.

stay the same when the system pressure drops.

decrease when system demand drops.

stay the same when system demand increases.

Correct! Wrong!

When the fluid in a hydraulic system appears gray and milky, the problem is likely to be

water in the system.

no problem, it is normal.

excessive pressure.

excessive temperature.

Correct! Wrong!

When changing a hydraulic filter you should

save all filter cartridges for cleaning and re-use.

always use one that looks the same as the old.

match or cross-reference the old filter.

ensure the threads are the same diameter and pitch.

Correct! Wrong!

When replacing a hydraulic pump you should

make certain the new pump has the same rotation, flow and pressure ratings.

make sure the threaded holes are compatible or that adaptors are available.

pour oil into the outlet of the pump to pre-charge and ensure initial lubrication.

all of the above are correct.

Correct! Wrong!

For the purpose of this program, hydraulics is defined as the use of

a gas under pressure.

a liquid under pressure.

a gas, air mixture under pressure.

a liquid, air mixture under pressure.

Correct! Wrong!

Tubing is sized or gauged by its

inside diameter.

outside diameter.

ID and wall thickness.

OD and wall thickness.

Correct! Wrong!

The angle that most flared steel hydraulic hose adapters or couplings use is a

37 degrees flare.

45 degrees flare.

59 degrees flare.

60 degrees flare.

Correct! Wrong!

Upon inspection of a failed hose, it is found that the inner core is cracked and the hose is hard and stiff. The probable cause of failure would be

fluid incompatibility.

excessive heat.

high frequency pressure impulses.

hose bent too tightly.

Correct! Wrong!

Flow rate is best defined as

a measure of the volume (G.P.M.) of fluid that passes a given point in a given time.

a measure of the speed (velocity) of fluid that passes a given point in a given time.

the average speed of a fluid past a given point.

viscosity of liquids in motion.

Correct! Wrong!

One of the basic principles which makes hydraulic action almost instantaneous is that liquid is

compressible, transmits power by compressing.

non-compressible, and applies pressure in all directions.

can be pumped and directed to do work via simple hoses.

not subject to freezing in cold weather and is easily warmed when worked.

Correct! Wrong!

A double acting cylinder is a device that converts fluid power into

linear motion in one direction.

linear motion in two directions.

rotary motion in one direction.

rotary motion in two directions.

Correct! Wrong!

Directional control valves

direct hydraulic fluid to actuator.

direct hydraulic fluid to pump.

control system pressure.

control hydraulic fluid to pump inlet.

Correct! Wrong!

The principle of the operation of a hydraulic motor is

work is done by fluid flow under pressure.

mechanically turned to produce fluid flow.

the same as a hydraulic pump.

work is done mechanically, and controlled hydraulically.

Correct! Wrong!

A very frequent cause of hydraulic pump failure is the use of dirty or poor quality oil

True

False

Correct! Wrong!

AVITATION is the mixing of water and oil.

True

False

Correct! Wrong!

Water in hydraulic oil will give the oil a clear look.

True

False

Correct! Wrong!

Air in the system will causes the system to operate slowly.

True

False

Correct! Wrong!

Low oil level could cause foaming of oil in the hydraulic system.

True

False

Correct! Wrong!

An accumulator may be used in a system to store energy.

True

False

Correct! Wrong!

An orifice will create a pressure drop in the hydraulic circuit.

True

False

Correct! Wrong!

Dynamic sealing is the sealing of an object at rest.

True

False

Correct! Wrong!

If the down stream side of an orifice is blocked, the pressure will equalize on each side of the orifice.

True

False

Correct! Wrong!

Slight weepage at a dynamic seal is permissible for seal lubrication.

True

False

Correct! Wrong!

The figure below represents a

weight loaded accumulator.

single acting cylinder.

spring loaded accumulator.

pressure actuated receiver.

Correct! Wrong!

The device below represents a

pressure control valve.

volume control valve.

directional control valve.

spring return cylinder.

Correct! Wrong!

A good safety practice to follow when you begin any troubleshooting or service work on a hydraulic system is to have a container to catch hydraulic fluid.

True

False

Correct! Wrong!

Schematic drawings of the hydraulic circuits of a piece of equipment are always exact indications of the way the system is configured.

True

False

Correct! Wrong!

If a loader bucket drops slightly while holding a load, with control valve in neutral position, it might be caused by

control valve not centering properly.

oil leaking past cylinder packings or O-rings.

oil leaking past control valve or a relief valve.

all of the above.

Correct! Wrong!

Damage to hydraulic lines severe enough to cause a system blockage are always visible from the outside.

True

False

Correct! Wrong!

Hydraulic systems in which the fluid is confined under pressure are known as hydrostatic.

True

False

Correct! Wrong!

The man credited with verifying the principles on which modern hydraulics is founded is

Pascal.

Boyle.

Beroulli.

Einstein.

Correct! Wrong!

A demonstration system has two hydraulic cylinders connected by a hose. One cylinder is larger in diameter than the other. If the piston in the larger cylinder is pushed down a certain distance, the piston in the smaller cylinder will

move up an equal distance.

move up at the same speed.

move up a greater distance and at the same speed.

move further and faster than the larger piston.

Correct! Wrong!

To calculate pressure in a hydraulic system

multiply force by area.

multiply area by force.

divide force by area.

divide area by force.

Correct! Wrong!

To calculate the area of a circle, you can use either of the two formulas

3.14 R squared.

3.14 D squared.

0.785 D squared.

0.785 R squared.

Correct! Wrong!

In a confined hydraulic system, the pressure produced will increase as the area of the input piston decreases.

True

False

Correct! Wrong!

In a confined hydraulic system (floor jack), the force produced will increase as the area of the output piston decreases.

True

False

Correct! Wrong!

Hydraulic flow is created by

gravity

difference in pressure.

resistance in the lines.

velocity of the fluid.

Correct! Wrong!

For a given flow rate of hydraulic fluid, a decrease in the diameter of the line will mean a corresponding decrease in the velocity of the fluid.

True

False

Correct! Wrong!

The component that converts hydraulic flow and pressure into mechanical force is the

pump.

reservoir.

cylinder.

control valve.

Correct! Wrong!

The component that is driven by mechanical force to create hydraulic flow is the

pump.

relief valve.

cylinder.

control valve.

Correct! Wrong!

The difference between an unbalanced vane pump and a balanced vane pump is the

Cavitation could occur when

An open center hydraulic system can best be described as one in which

A four connection (four way) spool valve is used in conjunction with a

In the illustration below, what type of hydraulic system is being illustrated?

Viscosity of a liquid can best be described as

The oil inlet hole size of a hydraulic pump should

have different style threads or fittings than the outlet.

Hydraulic hose #SAE100R2AT-8 purchased from a supplier is marked for application. The -8 number used for sizing hydraulic hose refers to its inner diameter in

To evaluate a hydraulics system, when flow and pressure testing a piece of equipment, the flow rate is best defined as

In a system with a variable displacement pump, the volume of the fluid moved by the pump will

When the fluid in a hydraulic system appears gray and milky, the problem is likely to be

When changing a hydraulic filter you should

When replacing a hydraulic pump you should

For the purpose of this program, hydraulics is defined as the use of

Tubing is sized or gauged by its

The angle that most flared steel hydraulic hose adapters or couplings use is a

Upon inspection of a failed hose, it is found that the inner core is cracked and the hose is hard and stiff. The probable cause of failure would be

Flow rate is best defined as

One of the basic principles which makes hydraulic action almost instantaneous is that liquid is

A double acting cylinder is a device that converts fluid power into

Directional control valves

The principle of the operation of a hydraulic motor is

A very frequent cause of hydraulic pump failure is the use of dirty or poor quality oil

AVITATION is the mixing of water and oil.

Water in hydraulic oil will give the oil a clear look.

Air in the system will causes the system to operate slowly.

Low oil level could cause foaming of oil in the hydraulic system.

An accumulator may be used in a system to store energy.

An orifice will create a pressure drop in the hydraulic circuit.

Dynamic sealing is the sealing of an object at rest.

If the down stream side of an orifice is blocked, the pressure will equalize on each side of the orifice.

Slight weepage at a dynamic seal is permissible for seal lubrication.

The figure below represents a

The device below represents a

A good safety practice to follow when you begin any troubleshooting or service work on a hydraulic system is to have a container to catch hydraulic fluid.

Schematic drawings of the hydraulic circuits of a piece of equipment are always exact indications of the way the system is configured.

If a loader bucket drops slightly while holding a load, with control valve in neutral position, it might be caused by

Damage to hydraulic lines severe enough to cause a system blockage are always visible from the outside.

Hydraulic systems in which the fluid is confined under pressure are known as hydrostatic.

The man credited with verifying the principles on which modern hydraulics is founded is

A demonstration system has two hydraulic cylinders connected by a hose. One cylinder is larger in diameter than the other. If the piston in the larger cylinder is pushed down a certain distance, the piston in the smaller cylinder will

To calculate pressure in a hydraulic system

To calculate the area of a circle, you can use either of the two formulas

In a confined hydraulic system, the pressure produced will increase as the area of the input piston decreases.

In a confined hydraulic system (floor jack), the force produced will increase as the area of the output piston decreases.

Hydraulic flow is created by

For a given flow rate of hydraulic fluid, a decrease in the diameter of the line will mean a corresponding decrease in the velocity of the fluid.

The component that converts hydraulic flow and pressure into mechanical force is the

The component that is driven by mechanical force to create hydraulic flow is the

Success!

Heavy-Duty Mechanic - Trucks & Equipment