SPI PRACTICE QUESTIONS &
ACCURATE ANSWERS ALL PASSED
100% ALREADY GRADED A+
Sound waves are: CORRECT ANSWER - longitudinal, mechanical
The speed of sound in soft tissue is closest to: CORRECT ANSWER - 1,500 m/s
The frequency closest to the lower limit of ultrasound is: CORRECT ANSWER - 15,000 Hz
Which is not an acoustic variable? CORRECT ANSWER - intensity
The effects of soft tissue on ultrasound are called: CORRECT ANSWER - acoustic propagation
properties
All of the following are true EXCEPT: CORRECT ANSWER - two waves with identical frequencies
must interfere constructively
Put in decreasing order: deci, deca, micro, centi CORRECT ANSWER - deca, deci, centi micro
______________ is the time to complete one cycle CORRECT ANSWER - period
Which of the following sound waves is ultrasonic and least useful? CORRECT ANSWER - 30 KHz
What is the frequency of a wave with a 1 msec period? CORRECT ANSWER - 1 KHz
,______________ is the distance covered by one cycle CORRECT ANSWER - wavelength
Which of the following is determined by the source and the medium? CORRECT ANSWER -
range resolution
Propagation speed = ______________ x wavelength CORRECT ANSWER - frequency
As a result of ______________, the propagation speed increases CORRECT ANSWER -
decreasing compressibility and density
Put in decreasing order of propagation speed: gas, liquid, solid CORRECT ANSWER - solid, liquid,
gas
If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
wavelength? CORRECT ANSWER - halved
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its
wavelength? CORRECT ANSWER - .15 mm
If the frequency of an US wave is doubled, what happens to the period? CORRECT ANSWER -
halved
If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the propagation
speed? CORRECT ANSWER - remains the same
The units of PRF are: CORRECT ANSWER - per minute
,The time from the beginning of a pulse until its end is ______________? CORRECT ANSWER -
pulsed duration
What happens to the speed of sound in a medium when the bulk modulus of the medium
increases? CORRECT ANSWER - faster
___________ resolution is determined by SPL CORRECT ANSWER - radial or axial
If a wave's amplitude is doubled, what happens to the power? CORRECT ANSWER - quadrupled
Power of sound has units of: CORRECT ANSWER - watts
If the intensity of a sound beam remains unchanged while the beam area is reduced in half,
what has happened to the power? CORRECT ANSWER - halved
Which of these intensities is the smallest? SATP, SPTP, SATA CORRECT ANSWER - SATA
The duty factor for CW ultrasound is: CORRECT ANSWER - 1.0
What is the minimum value of the duty factor? CORRECT ANSWER - 0%
What are the units of intensity? CORRECT ANSWER - watts/cm2
What happens to the speed of sound in a medium when the bulk modulus of the medium
decreases? CORRECT ANSWER - slower
The units of attenuation are ______; this is a ______________ scale CORRECT ANSWER - dB,
logarithmic
, Sound intensity is decreased by 75%. How many decibels of attenuation is that? CORRECT
ANSWER - 6 dB
The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic
frequency? CORRECT ANSWER - 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? CORRECT ANSWER -
10 cm
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the longest
wavelength? CORRECT ANSWER - bone
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the shortest
wavelength? CORRECT ANSWER - air
What is the approximate attenuation coefficient of 1 MHz US in soft tissue? CORRECT ANSWER
- .5 dB/cm
Rayl is the unit of: CORRECT ANSWER - impedance
Impedance is the _________ of _________ and _________ CORRECT ANSWER - product,
propagation speed, density
What are attenuation's three components? CORRECT ANSWER - scattering, reflection,
absorption
ACCURATE ANSWERS ALL PASSED
100% ALREADY GRADED A+
Sound waves are: CORRECT ANSWER - longitudinal, mechanical
The speed of sound in soft tissue is closest to: CORRECT ANSWER - 1,500 m/s
The frequency closest to the lower limit of ultrasound is: CORRECT ANSWER - 15,000 Hz
Which is not an acoustic variable? CORRECT ANSWER - intensity
The effects of soft tissue on ultrasound are called: CORRECT ANSWER - acoustic propagation
properties
All of the following are true EXCEPT: CORRECT ANSWER - two waves with identical frequencies
must interfere constructively
Put in decreasing order: deci, deca, micro, centi CORRECT ANSWER - deca, deci, centi micro
______________ is the time to complete one cycle CORRECT ANSWER - period
Which of the following sound waves is ultrasonic and least useful? CORRECT ANSWER - 30 KHz
What is the frequency of a wave with a 1 msec period? CORRECT ANSWER - 1 KHz
,______________ is the distance covered by one cycle CORRECT ANSWER - wavelength
Which of the following is determined by the source and the medium? CORRECT ANSWER -
range resolution
Propagation speed = ______________ x wavelength CORRECT ANSWER - frequency
As a result of ______________, the propagation speed increases CORRECT ANSWER -
decreasing compressibility and density
Put in decreasing order of propagation speed: gas, liquid, solid CORRECT ANSWER - solid, liquid,
gas
If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
wavelength? CORRECT ANSWER - halved
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its
wavelength? CORRECT ANSWER - .15 mm
If the frequency of an US wave is doubled, what happens to the period? CORRECT ANSWER -
halved
If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the propagation
speed? CORRECT ANSWER - remains the same
The units of PRF are: CORRECT ANSWER - per minute
,The time from the beginning of a pulse until its end is ______________? CORRECT ANSWER -
pulsed duration
What happens to the speed of sound in a medium when the bulk modulus of the medium
increases? CORRECT ANSWER - faster
___________ resolution is determined by SPL CORRECT ANSWER - radial or axial
If a wave's amplitude is doubled, what happens to the power? CORRECT ANSWER - quadrupled
Power of sound has units of: CORRECT ANSWER - watts
If the intensity of a sound beam remains unchanged while the beam area is reduced in half,
what has happened to the power? CORRECT ANSWER - halved
Which of these intensities is the smallest? SATP, SPTP, SATA CORRECT ANSWER - SATA
The duty factor for CW ultrasound is: CORRECT ANSWER - 1.0
What is the minimum value of the duty factor? CORRECT ANSWER - 0%
What are the units of intensity? CORRECT ANSWER - watts/cm2
What happens to the speed of sound in a medium when the bulk modulus of the medium
decreases? CORRECT ANSWER - slower
The units of attenuation are ______; this is a ______________ scale CORRECT ANSWER - dB,
logarithmic
, Sound intensity is decreased by 75%. How many decibels of attenuation is that? CORRECT
ANSWER - 6 dB
The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic
frequency? CORRECT ANSWER - 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? CORRECT ANSWER -
10 cm
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the longest
wavelength? CORRECT ANSWER - bone
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the shortest
wavelength? CORRECT ANSWER - air
What is the approximate attenuation coefficient of 1 MHz US in soft tissue? CORRECT ANSWER
- .5 dB/cm
Rayl is the unit of: CORRECT ANSWER - impedance
Impedance is the _________ of _________ and _________ CORRECT ANSWER - product,
propagation speed, density
What are attenuation's three components? CORRECT ANSWER - scattering, reflection,
absorption
