Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

DMSO Physics > final review from canvas file > Flashcards

final review from canvas file Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Which is larger macro or micro

A

macro means bigger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

symbol for millions

A

mega

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

symbol for millionths

A

micro

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

symbol for hundreds

A

hecto

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

symbol for hundreths

A

centi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

a frequency of 15,000 hz is

A

audible sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

if power in a wave is halved the intensity is reduced to

A

half

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

if the amplitude of a wave is increased 3 times, the intensity is increased by

A

9 times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

propagations speed is determined by

A

medium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

propagations speed increases as frequency increases or decreases

A

false

not realated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how many intensities are needed to calculate decibels

A

two

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

path length increases what happens to the attenuation

A

increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which is lower spatial peak or spatial average intensity

A

spatial average

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

in addition to location in a beam, intensities also vary with

A

time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

the most important intensity in soft tissue is

A

SPTA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

duty factor is a unitless number between

A

0 and 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

intensities may be reported in various ways in respect to

A

time and space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

duty factor for a pulsed ultrasound system is typically

A

0.2%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

beam intensity is the same at different depths and lateral locations

true/false

A

FALSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

at a particular depth the center of a beam is more intense than the edges

true/false

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

temporal peak is the maximum intensity in

A

time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

3 MHz is how many Hz

A

3 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how much bigger is a billion than a million

A

1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the units of a wavelength

A

mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what are the units of frequency

A

Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what are the units of intensity

A

w/cm^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what are the units of propagatoin speed

A

m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what are the units of period

A

us

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is determined by sound source

A

period

frequency

amplitude

power

intensity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

if the intensity is the same while the power is doubled what happens to the beam area

A

increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

sound beam travels a total of 10cm in 2 sec. What is the speed of sound in this medium

A

5 cm/sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what term describes the time from the start of a pulse to the end of the pulse

A

pulse duration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

PRF is the recipricol of

A

PRP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

dB is a mathmatical representatoin with a __________scale

A

logarithmic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

rayleigh scattering is related to

A

frequency^4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

which media has the greatest attentuatoin and slowest speed

A

Air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what mathmatically describes the physics of refraction

A

snells law sin (tran)/ sin(inc)= speed 2/speed 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

two PZT crystals are made from the same material. The thicker will have a pulse transducer with

A

lower frequency and slower speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

when PZT exceeds the curie point the PZT

A

depolarizes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

PZT is also known as

A

crystal, active element, ceramic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what reduces the ringing in a transducer

A

backing material

42
Q

mathmatically the Q factor is the frequency divided by the

A

bandwidth

43
Q

imaging transducers are also referred to as

A

pulsed wave transducer

44
Q

what type of crystal will produce sound with the lowest freq

A

thick and slow

45
Q

the damping material in the transducer improves the systems what resolution

A

axial

46
Q

if the electrical excitation volt is 6MHz then the output freq of a CW transducer is

A

6 MHz

47
Q

the impedance of a transducer active element is 19Mrayls, and the impedance of the skin is 14Mrayls. What is an acceptable impedance for the matching layer

A

anything between 14 and 19 Mrayls

48
Q

which transducer component is a thin barrier of cork or rubber that isolates or uncouples the internal components from the case

A

acoustic insulator

49
Q

what is the purpose of the backing material in an imaging transducer

A

reduce ringing and improve axial resolution

50
Q

what creates the beam with deepest focus

A

large diameter and high freq

51
Q

how are freq and near zone length related

A

directly, lower freq shorter near zone

52
Q

what crystal creates the least divergence

A

large diameter higher freq

53
Q

what creates the most divergence

A

small diameter

lower frequency

54
Q

what determines the freq of sound created by a pulsed transducer

A

thickness and speed of the PZT

55
Q

what determines the spread of a sound beam in the far field

A

diameter of crystal and frequncy

56
Q

frequency does not change, if the diameter of the new PZT increases what happens to the wavelength

A

no change

57
Q

imaging to greater depths requires the listeing time to

A

increases

58
Q

when reporting a beams intensity the maximum is referred to as

A

SPTP

59
Q

the highest temporal intensity is

A

temporal peak

60
Q

units for reporting intensity are

A

w/cm^2

61
Q

what is measured where intensity is maximum and averaged over time

A

SPTA

62
Q

which intesity is measureed over the entire cross section of the beam and over all time

A

SATA

63
Q

what is the same as normal incidence

A

perpendicular, orthogonal, right angle, 90 degrees

64
Q

intensity of a sound beam just prior to striking a boundry is referred to as

A

incident intensity

65
Q

the portion of a sound beam that contimnues on after striking a boundry is the

A

transmitted intensity

66
Q

the percentage of US intensity that is allowed to pass through when the beam reaches a boundry between two media is referred to as

A

intensity transmission coefficient

67
Q

a sound beam with an intensity of 50 w/cm^2 strikes a boundry and is totally reflected. What is the intensity reflectoin coefficient

A

100%

68
Q

the intensity reflection coefficient of sound is 99.9% . What percentage is transmitted into the body

A

0.1%

69
Q

specular reflections arise when the interface is

A

smooth

70
Q

what do we know about oblique incidence

A

nothing

71
Q

transmission with a bend is

A

refraction

72
Q

Snells law describes what physics

A

refraction

73
Q

sound waves strike a boundry at normal incidence. The impedances of the two are identical. What percentage of the beam is reflected

A

0%

must be difference in impedance for reflection to occur

74
Q

what processes occur as the ultrasound passes through all media

A

reflection, scattering and absorption

75
Q

two waves are traveling through a medium and arrive at a location at the same time. What event takes place

A

interference

76
Q

the percentage of time that a system is transmitting a pulse is referred to as

A

duty factor

77
Q

a 3MHz beam travels though two media. It attentuates 5 dB in A and 6 dB in B.

What is the total attenuation of the beam

A

11 dB

78
Q

what is the dominant factor in attenuation

A

absorption

79
Q

impedance is a characteristic of

A

acoustic resistance of sound traveling in media

density x propagation speed

80
Q

hertz is a unit used to describe what wave characteristic

A

frequency

81
Q

a low freq transducer is best at imaging what structures? Deep or shallow

A

deep

82
Q

The percentage of the US intensity that is allowed to pass through when the beam reaches a boundary between two media is

A

intensity transmission coefficient

83
Q

what is the best estimate for attenuation coefficient of sound traveling in soft tissue

A

.5 dB/cm/MHz

84
Q

Attenuation is determined by two factors

A

path length and freq of sound

85
Q

With longer distances and higher frequencies you have

A

higher attenuation

86
Q

With shorter distances and lower frequencies you have

A

lower attentuation

87
Q

Because attenuation means a weakening or a decrease, the dbs must be

A

negative

88
Q

Which term best describes redirection of sound in many directions

A

scattering

89
Q

Reflections from a smooth reflector are referred to as

A

specular

90
Q

When a boundary is rough, reflected sound is disorganized and random, also called

A

diffuse or backscatter

91
Q

Rayleigh scattering increases dramatically with increasing frequency, which is the relation

A

frequency 4

92
Q

Acoustic Impedance is equal to

A

density x propagation speed

93
Q

The time needed for a pulse to travel to and from the transducer and the reflector is called

A

go return time, time of flight,

94
Q

A sound wave is created by the transducer, reflects off an object and returns to the transducer in 52, what is the reflector depth and total distance traveled

A

4 cm depth and 8 cm total travel

95
Q

The maximum imaging depth during an ultrasound exam is 5 cm. The sonographer adjusts the depth to 10cm.

What happens to pulse repetition frequency

A

PRF is halved

96
Q

A sound wave is created by the transducer, reflects off an object, and returns to the transducer. The time of flight is 130 microseconds. What is the maximum PRF

A

7,700 Hz

97
Q

A sound wave is created by the transducer, reflects off an object, and returns to the transducer. The go return time is 39 microseconds. What is the total distance traveled

A

6 cm

98
Q

Axial resolution deals with structures that are ___________to the sound beam

A

parallel

99
Q

As frequency increases, the numerical value of LARRD resolution

A

lowers

100
Q

Superior axial resolution is associated with the following

A

shorter spatial pulse length, shorter pulse duratoin, higher Freq, fewer cycles per pulse, lower numerical values

DMSO Physics (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions