Physics Soundwaves Test Study Guide

Question 1

_______ _______ = The measure of resistance to sound traveling through a medium

Answer 1

Acoustic impedance

Question 2

_______ of _______ = The angle from normal at which the sound beam strikes and interface

Answer 2

Angle of incidence

Question 3

_______ = Encompasses absorption, scattering, divergence and reflection

Answer 3

Attenuation

Question 4

_______ = Units of measure are w/cm^2

Answer 4

Intensity

Question 5

_______ = Normally the dominant contribution to attentuation

Answer 5

Absorption

Question 6

_______ = The concentration of energy in a sound beam

Answer 6

Intensity

Question 7

_______ or _______ = Relates to the strength of the sound beam

Answer 7

Amplitude/Power

Question 8

_______ = The junction of two media with different acoustic properties

Answer 8

Interface

Question 9

_______ = The conversion of sound to heat

Answer 9

Absorption

Question 10

_______ = Units of measure are Watts or milliwatts

Answer 10

Power

Question 11

_______ = Equals the maximum variation of an acoustic variable

Answer 11

Amplitude

Question 12

_______ _______ = A sound beam intersects a smooth surface larger than the width of the beam at < 90

Answer 12

Oblique incidence

Question 13

_______ = Limits imaging depth and must be compensated for

Answer 13

Attenuation

Question 14

_______ = Rate at which energy is transmitted

Answer 14

Power

Question 15

_______ = The spreading out of a beam that results from a source of small physical dimensions

Answer 15

Divergence

Question 16

_______ = The decrease in strength/intensity as a beam traverses a medium

Answer 16

Attenuation

Question 17

Frequency is a measure of how many _______ an acoustic variable goes through in a second.

Answer 17

cycles

Question 18

The unit of frequency is the _______, which is abbreviated _______

Answer 18

Hertz

Hz

Question 19

Period is the _______ that it takes for one cycle to occur

Answer 19

time

Question 20

Period is one divided by _______

Answer 20

frequency

Question 21

Wavelength is the _______ over which one cycle occurs

Answer 21

space

Question 22

Wavelength is equal to _______ _______ divided by _______

Answer 22

Propagation speed

frequency

Question 23

The average propagation speed in soft tissues is _______ m/s or _______ mm/microseconds

Answer 23

1,540

1.54

Question 24

Propagation speed is determined by _______

Answer 24

medium

Question 25

Length of time to complete one cycle

Answer 25

period

Question 26

Time of the start of one cycle to the start of the next cycle.

Answer 26

period

Question 27

Attenuation is the reduction of _______/_______ as the wave travels through a medium.

Answer 27

Strength | Intensity

Question 28

If power is doubled, and area remains unchanged, Intensity is _______

Answer 28

doubled

Question 29

If amplitude is doubled, and area remains unchanged, power is _______

Answer 29

quadrupled

Question 30

BONUS: What is the formula describing temporal resolution and its relationship with the depth and other factors that effect the pulse repetition frequency.

Answer 30

P x LPF x FR x NF < (line below less then sign because its less than or equal to) 77,000

Question 31

List four factors affecting the strength of a reflected echo

Answer 31

1) The degree of acoustic impedance mismatch 2) Inherent strength of the incident ultrasound beam 3) The angle at which the US beam strikes a reflecting surface 4) Size of the reflector

Question 32

_______ _______ = The measure of resistance to sound traveling through a medium

Answer 32

Acoustic Impedance

Question 33

BONUS: In oblique incidence, the angle of reflection _______ the angle of incidence

Answer 33

Equals

Question 34

As density increases, impedance _______

Answer 34

increases

Question 35

Bone = _______ Rayls Soft Tissue = _______ Rayls Fat = _______ Rayls Lung = _______ Rayls

Answer 35

7. 8 1. 63 1. 38 0. 26

Question 36

In perpendicular incidence, the angle of reflection _______ the angle of incidence

Answer 36

Equals

Question 37

A decrease in impedance difference will result in a _______ in transmitted sound

Answer 37

increase

Question 38

As propagation speed decreases, impedance _______

Answer 38

decreases

Question 39

To obtain maximum detection of the reflected signal, we must orient the transducer so the generated sound beam will strike a interface _______

Answer 39

perpendicular

Question 40

Smooth interfaces, larger than the beam width _______ (specular reflector or scatterer)

Answer 40

Specular reflector

Question 41

Very frequency dependant

Answer 41

scatterer

Question 42

Tiny, punctate reflectors that scatter a small portion of the beam in almost all directions

Answer 42

scatterer

Question 43

Produce high-intensity, unidirectional reflections

Answer 43

specular

Question 44

Provide the US texture within organs

Answer 44

scatterer

Question 45

Very angle dependant

Answer 45

specular

Question 46

These are responsible for major organ outline as seen by US; i.e., diaphragm

Answer 46

specular

Question 47

RBCs are a specific type

Answer 47

scatterer

Question 48

Transducer type: Mechanical = _______ Image shape

Answer 48

Sector

Question 49

Transducer Type: Linear Switched/Sequenced = _______ Image shape

Answer 49

Rectangular

Question 50

Transducer type: Linear Phased = _______ Image shape

Answer 50

sector

Question 51

Transducer Type: Annular Phased = _______ Image shape

Answer 51

sector

Question 52

Transducer Type: Convex Sequential = _______ Image shape

Answer 52

Blunted sector

Question 53

Transducer Type: Convex Phased = _______ Image shape

Answer 53

Blunted sector

Question 54

Transducer Type: Vector = _______ Image shape

Answer 54

Flat top sector

Question 55

The imaging depth ______ as frequency increases

Answer 55

decreases

Question 56

Attenuation consists of _______, _______, and _______ if its a fourth option then it would be ________

Answer 56

absorption scattering divergence reflection

Question 57

If frequency is doubled and path length is halved, attention __________

Answer 57

remains the same