Sound waves are: - ANSWERSlongitudinal, mechanical
The speed of sound in soft tissue is closest to: - ANSWERS1,500 m/s
The frequency closest to the lower limit of ultrasound is: - ANSWERS15,000 Hz
Which is not an acoustic variable? - ANSWERSintensity
The effects of soft tissue on ultrasound are called: - ANSWERSacoustic propagation
properties
All of the following are true EXCEPT: - ANSWERStwo waves with identical frequencies
must interfere constructively
Put in decreasing order: deci, deca, micro, centi - ANSWERSdeca, deci, centi micro
______________ is the time to complete one cycle - ANSWERSperiod
Which of the following sound waves is ultrasonic and least useful? - ANSWERS30 KHz
What is the frequency of a wave with a 1 msec period? - ANSWERS1 KHz
______________ is the distance covered by one cycle - ANSWERSwavelength
Which of the following is determined by the source and the medium? - ANSWERSrange
resolution
Propagation speed = ______________ x wavelength - ANSWERSfrequency
As a result of ______________, the propagation speed increases -
ANSWERSdecreasing compressibility and density
Put in decreasing order of propagation speed: gas, liquid, solid - ANSWERSsolid, liquid,
gas
If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
wavelength? - ANSWERShalved
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its
wavelength? - ANSWERS.15 mm
If the frequency of an US wave is doubled, what happens to the period? -
ANSWERShalved
If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the
propagation speed? - ANSWERSremains the same
,The units of PRF are: - ANSWERSper minute
The time from the beginning of a pulse until its end is ______________? -
ANSWERSpulsed duration
What happens to the speed of sound in a medium when the bulk modulus of the
medium increases? - ANSWERSfaster
___________ resolution is determined by SPL - ANSWERSradial or axial
If a wave's amplitude is doubled, what happens to the power? - ANSWERSquadrupled
Power of sound has units of: - ANSWERSwatts
If the intensity of a sound beam remains unchanged while the beam area is reduced in
half, what has happened to the power? - ANSWERShalved
Which of these intensities is the smallest? SATP, SPTP, SATA - ANSWERSSATA
The duty factor for CW ultrasound is: - ANSWERS1.0
What is the minimum value of the duty factor? - ANSWERS0%
What are the units of intensity? - ANSWERSwatts/cm2
What happens to the speed of sound in a medium when the bulk modulus of the
medium decreases? - ANSWERSslower
The units of attenuation are ______; this is a ______________ scale - ANSWERSdB,
logarithmic
Sound intensity is decreased by 75%. How many decibels of attenuation is that? -
ANSWERS6 dB
The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic
frequency? - ANSWERS5 MHz
A pulse is emitted by a transducer and is traveling in soft tissue. The go-return-time, or
time-of-flight, of a sound pulse is 130 microseconds. What is the reflector depth? -
ANSWERS10 cm
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the
longest wavelength? - ANSWERSbone
, If a 5 MHz sound wave is traveling in the tissues listed below, which will have the
shortest wavelength? - ANSWERSair
What is the approximate attenuation coefficient of 1 MHz US in soft tissue? -
ANSWERS.5 dB/cm
Rayl is the unit of: - ANSWERSimpedance
Impedance is the _________ of _________ and _________ - ANSWERSproduct,
propagation speed, density
What are attenuation's three components? - ANSWERSscattering, reflection, absorption
For soft tissue, the approximate attenuation coefficient in dB/cm is equal to one-half
_________ in _________ - ANSWERSfrequency, MHz
As the impedance of two media become vastly different , the: - ANSWERSreflection
increases
The angle between two media is 90 degrees. What is this called? -
ANSWERSorthogonal incidence
The angle between two media is 56 degrees. This is called: - ANSWERSoblique
incidence
Refraction only occurs if there are: - ANSWERSoblique incidence and different
propagation speeds
With normal incidence, what factors affect refraction? - ANSWERSnone of the above
T/F: With right angle incidence, reflections are always generated at a boundary if the
propagation speeds of the media are different - ANSWERSfalse
_________ is a redirection of US in many directions as a result of a *rough* boundary
between two media - ANSWERSscattering
Which of the following tissues will most likely create Rayleigh scattering? -
ANSWERSred blood cells
T/F: With normal incidence, the angle is 180 degrees. - ANSWERSfalse
Under which of the following conditions is axial resolution improved? -
ANSWERSdecreased SPL
Snell's law describes the physics of: - ANSWERSrefraction
The speed of sound in soft tissue is closest to: - ANSWERS1,500 m/s
The frequency closest to the lower limit of ultrasound is: - ANSWERS15,000 Hz
Which is not an acoustic variable? - ANSWERSintensity
The effects of soft tissue on ultrasound are called: - ANSWERSacoustic propagation
properties
All of the following are true EXCEPT: - ANSWERStwo waves with identical frequencies
must interfere constructively
Put in decreasing order: deci, deca, micro, centi - ANSWERSdeca, deci, centi micro
______________ is the time to complete one cycle - ANSWERSperiod
Which of the following sound waves is ultrasonic and least useful? - ANSWERS30 KHz
What is the frequency of a wave with a 1 msec period? - ANSWERS1 KHz
______________ is the distance covered by one cycle - ANSWERSwavelength
Which of the following is determined by the source and the medium? - ANSWERSrange
resolution
Propagation speed = ______________ x wavelength - ANSWERSfrequency
As a result of ______________, the propagation speed increases -
ANSWERSdecreasing compressibility and density
Put in decreasing order of propagation speed: gas, liquid, solid - ANSWERSsolid, liquid,
gas
If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
wavelength? - ANSWERShalved
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its
wavelength? - ANSWERS.15 mm
If the frequency of an US wave is doubled, what happens to the period? -
ANSWERShalved
If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the
propagation speed? - ANSWERSremains the same
,The units of PRF are: - ANSWERSper minute
The time from the beginning of a pulse until its end is ______________? -
ANSWERSpulsed duration
What happens to the speed of sound in a medium when the bulk modulus of the
medium increases? - ANSWERSfaster
___________ resolution is determined by SPL - ANSWERSradial or axial
If a wave's amplitude is doubled, what happens to the power? - ANSWERSquadrupled
Power of sound has units of: - ANSWERSwatts
If the intensity of a sound beam remains unchanged while the beam area is reduced in
half, what has happened to the power? - ANSWERShalved
Which of these intensities is the smallest? SATP, SPTP, SATA - ANSWERSSATA
The duty factor for CW ultrasound is: - ANSWERS1.0
What is the minimum value of the duty factor? - ANSWERS0%
What are the units of intensity? - ANSWERSwatts/cm2
What happens to the speed of sound in a medium when the bulk modulus of the
medium decreases? - ANSWERSslower
The units of attenuation are ______; this is a ______________ scale - ANSWERSdB,
logarithmic
Sound intensity is decreased by 75%. How many decibels of attenuation is that? -
ANSWERS6 dB
The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic
frequency? - ANSWERS5 MHz
A pulse is emitted by a transducer and is traveling in soft tissue. The go-return-time, or
time-of-flight, of a sound pulse is 130 microseconds. What is the reflector depth? -
ANSWERS10 cm
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the
longest wavelength? - ANSWERSbone
, If a 5 MHz sound wave is traveling in the tissues listed below, which will have the
shortest wavelength? - ANSWERSair
What is the approximate attenuation coefficient of 1 MHz US in soft tissue? -
ANSWERS.5 dB/cm
Rayl is the unit of: - ANSWERSimpedance
Impedance is the _________ of _________ and _________ - ANSWERSproduct,
propagation speed, density
What are attenuation's three components? - ANSWERSscattering, reflection, absorption
For soft tissue, the approximate attenuation coefficient in dB/cm is equal to one-half
_________ in _________ - ANSWERSfrequency, MHz
As the impedance of two media become vastly different , the: - ANSWERSreflection
increases
The angle between two media is 90 degrees. What is this called? -
ANSWERSorthogonal incidence
The angle between two media is 56 degrees. This is called: - ANSWERSoblique
incidence
Refraction only occurs if there are: - ANSWERSoblique incidence and different
propagation speeds
With normal incidence, what factors affect refraction? - ANSWERSnone of the above
T/F: With right angle incidence, reflections are always generated at a boundary if the
propagation speeds of the media are different - ANSWERSfalse
_________ is a redirection of US in many directions as a result of a *rough* boundary
between two media - ANSWERSscattering
Which of the following tissues will most likely create Rayleigh scattering? -
ANSWERSred blood cells
T/F: With normal incidence, the angle is 180 degrees. - ANSWERSfalse
Under which of the following conditions is axial resolution improved? -
ANSWERSdecreased SPL
Snell's law describes the physics of: - ANSWERSrefraction
