SPI PRACTICE QUESTIONS
The time from the beginning of a pulse until its end is ______________? - ✔️✔️pulsed
duration
If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the
propagation speed? - ✔️✔️remains the same
All of the following are true EXCEPT: - ✔️✔️two waves with identical frequencies must
interfere constructively
As a result of ______________, the propagation speed increases - ✔️✔️decreasing
compressibility and density
Sound waves are: - ✔️✔️longitudinal, mechanical
The speed of sound in soft tissue is closest to: - ✔️✔️1,500 m/s
The frequency closest to the lower limit of ultrasound is: - ✔️✔️15,000 Hz
Which is not an acoustic variable? - ✔️✔️intensity
The effects of soft tissue on ultrasound are called: - ✔️✔️acoustic propagation
properties
Put in decreasing order: deci, deca, micro, centi - ✔️✔️deca, deci, centi micro
______________ is the time to complete one cycle - ✔️✔️period
Which of the following sound waves is ultrasonic and least useful? - ✔️✔️30 KHz
What is the frequency of a wave with a 1 msec period? - ✔️✔️1 KHz
______________ is the distance covered by one cycle - ✔️✔️wavelength
Which of the following is determined by the source and the medium? - ✔️✔️range
resolution
Propagation speed = ______________ x wavelength - ✔️✔️frequency
Put in decreasing order of propagation speed: gas, liquid, solid - ✔️✔️solid, liquid, gas
,If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
wavelength? - ✔️✔️halved
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its
wavelength? - ✔️✔️.15 mm
If the frequency of an US wave is doubled, what happens to the period? - ✔️✔️halved
The units of PRF are: - ✔️✔️per minute
What happens to the speed of sound in a medium when the bulk modulus of the
medium increases? - ✔️✔️faster
___________ resolution is determined by SPL - ✔️✔️radial or axial
If a wave's amplitude is doubled, what happens to the power? - ✔️✔️quadrupled
Power of sound has units of: - ✔️✔️watts
Which of these intensities is the smallest? SATP, SPTP, SATA - ✔️✔️SATA
The duty factor for CW ultrasound is: - ✔️✔️1.0
What is the minimum value of the duty factor? - ✔️✔️0%
What are the units of intensity? - ✔️✔️watts/cm2
What happens to the speed of sound in a medium when the bulk modulus of the
medium decreases? - ✔️✔️slower
The units of attenuation are ______; this is a ______________ scale - ✔️✔️dB,
logarithmic
Sound intensity is decreased by 75%. How many decibels of attenuation is that? -
✔️✔️6 dB
The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic
frequency? - ✔️✔️5 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? -
✔️✔️10 cm
, If a 5 MHz sound wave is traveling in the tissues listed below, which will have the
longest wavelength? - ✔️✔️bone
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the
shortest wavelength? - ✔️✔️air
What is the approximate attenuation coefficient of 1 MHz US in soft tissue? - ✔️✔️.5
dB/cm
Rayl is the unit of: - ✔️✔️impedance
Impedance is the _________ of _________ and _________ - ✔️✔️product,
propagation speed, density
What are attenuation's three components? - ✔️✔️scattering, reflection, absorption
For soft tissue, the approximate attenuation coefficient in dB/cm is equal to one-half
_________ in _________ - ✔️✔️frequency, MHz
As the impedance of two media become vastly different , the: - ✔️✔️reflection
increases
The angle between two media is 90 degrees. What is this called? - ✔️✔️orthogonal
incidence
The angle between two media is 56 degrees. This is called: - ✔️✔️oblique incidence
Refraction only occurs if there are: - ✔️✔️oblique incidence and different propagation
speeds
With normal incidence, what factors affect refraction? - ✔️✔️none 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 - ✔️✔️false
_________ is a redirection of US in many directions as a result of a *rough* boundary
between two media - ✔️✔️scattering
Which of the following tissues will most likely create Rayleigh scattering? - ✔️✔️red
blood cells
T/F: With normal incidence, the angle is 180 degrees. - ✔️✔️false
The time from the beginning of a pulse until its end is ______________? - ✔️✔️pulsed
duration
If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the
propagation speed? - ✔️✔️remains the same
All of the following are true EXCEPT: - ✔️✔️two waves with identical frequencies must
interfere constructively
As a result of ______________, the propagation speed increases - ✔️✔️decreasing
compressibility and density
Sound waves are: - ✔️✔️longitudinal, mechanical
The speed of sound in soft tissue is closest to: - ✔️✔️1,500 m/s
The frequency closest to the lower limit of ultrasound is: - ✔️✔️15,000 Hz
Which is not an acoustic variable? - ✔️✔️intensity
The effects of soft tissue on ultrasound are called: - ✔️✔️acoustic propagation
properties
Put in decreasing order: deci, deca, micro, centi - ✔️✔️deca, deci, centi micro
______________ is the time to complete one cycle - ✔️✔️period
Which of the following sound waves is ultrasonic and least useful? - ✔️✔️30 KHz
What is the frequency of a wave with a 1 msec period? - ✔️✔️1 KHz
______________ is the distance covered by one cycle - ✔️✔️wavelength
Which of the following is determined by the source and the medium? - ✔️✔️range
resolution
Propagation speed = ______________ x wavelength - ✔️✔️frequency
Put in decreasing order of propagation speed: gas, liquid, solid - ✔️✔️solid, liquid, gas
,If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
wavelength? - ✔️✔️halved
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its
wavelength? - ✔️✔️.15 mm
If the frequency of an US wave is doubled, what happens to the period? - ✔️✔️halved
The units of PRF are: - ✔️✔️per minute
What happens to the speed of sound in a medium when the bulk modulus of the
medium increases? - ✔️✔️faster
___________ resolution is determined by SPL - ✔️✔️radial or axial
If a wave's amplitude is doubled, what happens to the power? - ✔️✔️quadrupled
Power of sound has units of: - ✔️✔️watts
Which of these intensities is the smallest? SATP, SPTP, SATA - ✔️✔️SATA
The duty factor for CW ultrasound is: - ✔️✔️1.0
What is the minimum value of the duty factor? - ✔️✔️0%
What are the units of intensity? - ✔️✔️watts/cm2
What happens to the speed of sound in a medium when the bulk modulus of the
medium decreases? - ✔️✔️slower
The units of attenuation are ______; this is a ______________ scale - ✔️✔️dB,
logarithmic
Sound intensity is decreased by 75%. How many decibels of attenuation is that? -
✔️✔️6 dB
The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic
frequency? - ✔️✔️5 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? -
✔️✔️10 cm
, If a 5 MHz sound wave is traveling in the tissues listed below, which will have the
longest wavelength? - ✔️✔️bone
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the
shortest wavelength? - ✔️✔️air
What is the approximate attenuation coefficient of 1 MHz US in soft tissue? - ✔️✔️.5
dB/cm
Rayl is the unit of: - ✔️✔️impedance
Impedance is the _________ of _________ and _________ - ✔️✔️product,
propagation speed, density
What are attenuation's three components? - ✔️✔️scattering, reflection, absorption
For soft tissue, the approximate attenuation coefficient in dB/cm is equal to one-half
_________ in _________ - ✔️✔️frequency, MHz
As the impedance of two media become vastly different , the: - ✔️✔️reflection
increases
The angle between two media is 90 degrees. What is this called? - ✔️✔️orthogonal
incidence
The angle between two media is 56 degrees. This is called: - ✔️✔️oblique incidence
Refraction only occurs if there are: - ✔️✔️oblique incidence and different propagation
speeds
With normal incidence, what factors affect refraction? - ✔️✔️none 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 - ✔️✔️false
_________ is a redirection of US in many directions as a result of a *rough* boundary
between two media - ✔️✔️scattering
Which of the following tissues will most likely create Rayleigh scattering? - ✔️✔️red
blood cells
T/F: With normal incidence, the angle is 180 degrees. - ✔️✔️false
