Navedtra 14105 Fluid Power Chapter 1-3

Front 1

True or False. The term "fluid power" includes hydraulics and pneumatics, and is power that is applied through liquids or gases pumped or compressed to provide force and motion to mechanisms.

Back 1

True

Front 2

The prupose of your textbook, Fluid Power, is to provide you with ?

Back 2

A basic reference concerning fundamentals of fluid power

Front 3

What are the favorable characteristics of a fluid power system?

Back 3

very large forces can be controlled by much smaller ones, different parts of the system can be located at widely separated points, and motion can be transmitted without the slack inherent in the use of solid machine

Front 4

What type of system requires a medium amount of pressure and fairly accurate control?

Back 4

pneumatic

Front 5

What type of system requires a medium amount of pressure and more accurate control?

Back 5

combination hydraulic and pneumatic

Front 6

What type of system requires a great amount of pressure and/ or extremely accurate control?

Back 6

Hydraulic

Front 7

What are special problems of fluid power systems?

Back 7

loss in efficiency as the force of the fluid is conveyed up and down or around corners, loss of force as the fluid is transmitted over considerable distances, and leaks

Front 8

The Study of hydraulics was originally confined to the study of the physical behavior of water at rest and in motion. The term "hydraulics" now includes the physical behavior of all?

Back 8

liquids

Front 9

Pascal's law pertains to the?

Back 9

transmission of force in confined fluids

Front 10

True or False. All matter is classified according to its state as a solid, liquid, or a gas.

Back 10

True

Front 11

The critical factors affecting the state of matter are?

Back 11

pressure and temperature

Front 12

True or False. Pressure can be measured in terms of force per unit area.

Back 12

True

Front 13

True or False. The troposphere is that part of the atmosphere touching the earth's surface.

Back 13

True

Front 14

True or False. The atmosphere has weight.

Back 14

True

Front 15

True or False. Atmospheric pressure decreases as altitude decreases.

Back 15

False

Front 16

True or False. Atmospheric pressure at points below sea level is less then at sea level.

Back 16

False

Front 17

The reference standard used as an indicator of atmospheric pressure is a column of mercury that at sea level is?

Back 17

76 centimeters high at 0 degrees Celsius

Front 18

The side of a thin-walled chamber partially evacuated of air is the source of movement for the?

Back 18

aneroid barometer

Front 19

In the metric system the density of a substance is its weight in?

Back 19

grams per cubic centimeter

Front 20

What change, if any, will occur in the volume and weight of a substance if its temperature changes?

Back 20

its volume will change, but its weight will remain constant

Front 21

True or False. Specific gravity will vary with the size of the sample being tested.

Back 21

False

Front 22

How can the specific gravity of a liquid or solid be expressed?

Back 22

As a ratio between the weight of the substance and the weight of an equal volume of water or as the number that shows the density of the substance in the metric system

Front 23

What is the specific gravity of a liquid which weighs 44 pounds per cubic foot at 4 degrees C?

Back 23

0.705

Front 24

What is the density of a solid that has a specific gravity of 2.5?

Back 24

156 pounds per cubic foot

Front 25

What is the specific gravity of a solid object which weighs 49.92 pounds per cubic foot?

Back 25

0.8

Front 26

A device used for measuring the specific gravity of a liquid is known as a?

Back 26

hydrometer

Front 27

True or False. The pressure of force exerted on the end of a rigid metal bar is applied equally and undiminished to all surfaces of the bar.

Back 27

True

Front 28

The head, or pressure due to the weight of a fluid, depends on the density of the fluid and the?

Back 28

area of the bottom surface of the container

Front 29

Assume that the input piston has an area of 3 square inches with a force of 45 pounds. What is the pressure in the system?

Back 29

15psi

Front 30

Assume that the output piston has a diameter of 6 inches and is subject to a pressure of 10 pounds per square inch. What is the force exerted on the output piston?

Back 30

282.6

Front 31

For two pistons in the same fluid power system, the distances moved are inversely proportional to the?

Back 31

areas of the pistons

Front 32

In fluid power systems using liquids, the measurement of the volume of fluid flow is made in units of?

Back 32

gallons per minute

Front 33

Water flows through a pipe of 5 square-inch cross section at the velocity of 3 feet per second (fps). At what velocity does it flow through a constriction in the pipe with a cross section of 3 square inches?

Back 33

5.0 fps

Front 34

True or False. Two pistons with defferent cross-sectional areas will travel at the same speed as long as the rate of fluid flow into their cylinders is identical.

Back 34

False

Front 35

In streamline flow, each particle of fluid moves in what manner?

Back 35

in parallel layers

Front 36

True or False. Losses due to friction increase with velocity at a higher rate in turbulent flow than in streamline flow.

Back 36

True

Front 37

What is inertia of fluids in a power system?

Back 37

the resistance of the fluid to movement or change of rate of movement

Front 38

Neglecting friction, how much force is required to accelerate 3 pounds of fluid from rest to a velocity of 322 feet per second in 2 seconds?

Back 38

15 pounds

Front 39

True or False. Head is a statement of force per unit area.

Back 39

True

Front 40

True or False. Velocity head is the loss of energy caused by inertia.

Back 40

False

Front 41

True or False. Gravity head depends on which portions of the system are exposed to open air.

Back 41

False

Front 42

True or False. Friction head connot exist without velocity head.

Back 42

True

Front 43

True or False. There can be no static head if the fluid is in motion.

Back 43

True

Front 44

What factors affecting fluid action are classified as static factors.

Back 44

Gravity, atmospheric pressure, and applied forces

Front 45

The similarity between hydraulic and pneumatic fluid power systems is corrctly indicated by what statement?

Back 45

The basic components of the systems are essentially the same

Front 46

What component of a hydraulic fluid power system performs the same function as the receiver in a pneumatic fluid power system?

Back 46

reservoir

Front 47

Liquids rather than gases are used in hydraulic systems because liquids are?

Back 47

less compressible

Front 48

A liquid that is satisfactory for use in a hydraulic system provides?

Back 48

good lubrication and sealing qualities, and a viscosity that does not result in an increase in flow resistance in system piping

Front 49

True or False. The viscosity reading of a liquid is expressed as Saybolt universal seconds (SUS), which represents the time, in seconds, it takes for 60 cubic centimeters of the liquid at a specified temperature to pass through an orifice of given diameter.

Back 49

True

Front 50

A low V.I. indicates that a liquid will?

Back 50

Vary greatly in viscosity with changes in temperature

Front 51

True or False. Liquids derived from the same source have equal resistance to heat.

Back 51

False

Front 52

True or False. The film strength and lubrication qualities of a liquid are directly related to the liquid's physical properties.

Back 52

False

Front 53

What happens to hydraulic liquid that is continuously subjected to high temperature conditions?

Back 53

It changes unfavorably in composition

Front 54

Define fluidity.

Back 54

The physical property that enables liquids to flow

Front 55

Define viscosity.

Back 55

The internal resistance that tends to prevent liquids from flowing

Front 56

Define chemical stability.

Back 56

The ability of liquids to resist oxidation and deterioration for long periods

Front 57

The desirable flashpoint of a hydraulic liquid is one which provides a?

Back 57

low degree of evaporation and good resistance to combustion.

Front 58

Hydraulic liquid must possess what properties?

Back 58

chemical stability and freedom from acidity, lubricating ability and proper viscosity, and minimum toxicity and high flashpoint

Front 59

Although manufacturers strive to produce hydraulic liquids that contain non toxic chemicals, some liquids contain chemicals that are harmful. How do these poisonous chemicals enter the body?

Back 59

Absorption through the skin, through the eyes or mouth, or through inhalation

Front 60

The bases of the most common types of hydraulic liquids are classified as?

Back 60

water, petroleum, or synthetic

Front 61

What is the most widely used medium for hydraulic systems?

Back 61

petroleum-based liquid

Front 62

What properties of a hydraulic liquid can be improved by addititves?

Back 62

viscosity, chemical stability, lubricating power

Front 63

The fluid currently being used in a hydraulic system that requires a nonflammable liquid will proabably be a?

Back 63

synthetic-based liquid

Front 64

True or False. Synthetic based fluids contain toxic chemicals.

Back 64

True

Front 65

True or False. You have accidentally gotten a synthetic hydraulic fluid in your eyes. You should flush your eyes for at LEAST 15 minutes and seek immediate medical attention.

Back 65

True

Front 66

You are required to dispose of contaminated synthetic fluid while deployed. How should you dispose of the fluid?

Back 66

place it in drums for disposal ashore

Front 67

True or False. Water-based fluids' resistance to fire depends on the vaporization and smothering effect of steam generated from water.

Back 67

True