SPI PRACTICE QUESTIONS 2025 With
Correct Answers
Sound waves are: - correct answer longitudinal, mechanical
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The speed of sound in soft tissue is closest to: - correct answer 1,500 m/s
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The frequency closest to the lower limit of ultrasound is: - correct answer 15,000 Hz
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Which is not an acoustic variable? - correct answer intensity
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The effects of soft tissue on ultrasound are called: - correct answer acoustic propagation properties
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All of the following are true EXCEPT: - correct answer two waves with identical frequencies must interfere
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constructively
Put in decreasing order: deci, deca, micro, centi - correct answer deca, deci, centi micro
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______________ is the time to complete one cycle - correct answer period d d d d d d d d d d d
,Which of the following sound waves is ultrasonic and least useful? - correct answer 30 KHz
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What is the frequency of a wave with a 1 msec period? - correct answer 1 KHz
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______________ is the distance covered by one cycle - correct answer wavelength d d d d d d d d d d d
Which of the following is determined by the source and the medium? - correct answer range resolution
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Propagation speed = ______________ x wavelength - correct answer frequency
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As a result of ______________, the propagation speed increases - correct answer decreasing compressibility
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and density d
Put in decreasing order of propagation speed: gas, liquid, solid - correct answer solid, liquid, gas
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If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the wavelength? - correct
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answer halved d
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its wavelength? - correct
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answer .15 mm d d
If the frequency of an US wave is doubled, what happens to the period? - correct answer halved
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If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the propagation speed? -
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correct answer remains the same
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The units of PRF are: - correct answer per minute
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The time from the beginning of a pulse until its end is ______________? - correct answer pulsed duration
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, What happens to the speed of sound in a medium when the bulk modulus of the medium increases? - correct
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answer faster d
___________ resolution is determined by SPL - correct answer radial or axial
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If a wave's amplitude is doubled, what happens to the power? - correct answer quadrupled
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Power of sound has units of: - correct answer watts
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If the intensity of a sound beam remains unchanged while the beam area is reduced in half, what has
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happened to the power? - correct answer halved d d d d d d d
Which of these intensities is the smallest? SATP, SPTP, SATA - correct answer SATA
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The duty factor for CW ultrasound is: - correct answer 1.0
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What is the minimum value of the duty factor? - correct answer 0%
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What are the units of intensity? - correct answer watts/cm2
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What happens to the speed of sound in a medium when the bulk modulus of the medium decreases? - correct
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answer slower d
The units of attenuation are ______; this is a ______________ scale - correct answer dB, logarithmic
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Sound intensity is decreased by 75%. How many decibels of attenuation is that? - correct answer 6 dB
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The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic frequency? - correct
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answer 5 MHz d d
Correct Answers
Sound waves are: - correct answer longitudinal, mechanical
d d d d d d d
The speed of sound in soft tissue is closest to: - correct answer 1,500 m/s
d d d d d d d d d d d d d d
The frequency closest to the lower limit of ultrasound is: - correct answer 15,000 Hz
d d d d d d d d d d d d d d
Which is not an acoustic variable? - correct answer intensity
d d d d d d d d d
The effects of soft tissue on ultrasound are called: - correct answer acoustic propagation properties
d d d d d d d d d d d d d d
All of the following are true EXCEPT: - correct answer two waves with identical frequencies must interfere
d d d d d d d d d d d d d d d d d
constructively
Put in decreasing order: deci, deca, micro, centi - correct answer deca, deci, centi micro
d d d d d d d d d d d d d d
______________ is the time to complete one cycle - correct answer period d d d d d d d d d d d
,Which of the following sound waves is ultrasonic and least useful? - correct answer 30 KHz
d d d d d d d d d d d d d d d
What is the frequency of a wave with a 1 msec period? - correct answer 1 KHz
d d d d d d d d d d d d d d d d
______________ is the distance covered by one cycle - correct answer wavelength d d d d d d d d d d d
Which of the following is determined by the source and the medium? - correct answer range resolution
d d d d d d d d d d d d d d d d
Propagation speed = ______________ x wavelength - correct answer frequency
d d d d d d d d d
As a result of ______________, the propagation speed increases - correct answer decreasing compressibility
d d d d d d d d d d d d d d
and density d
Put in decreasing order of propagation speed: gas, liquid, solid - correct answer solid, liquid, gas
d d d d d d d d d d d d d d d
If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the wavelength? - correct
d d d d d d d d d d d d d d d d d d d d
answer halved d
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its wavelength? - correct
d d d d d d d d d d d d d d d d d d d d
answer .15 mm d d
If the frequency of an US wave is doubled, what happens to the period? - correct answer halved
d d d d d d d d d d d d d d d d d
If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the propagation speed? -
d d d d d d d d d d d d d d d d d d
correct answer remains the same
d d d d
The units of PRF are: - correct answer per minute
d d d d d d d d d
The time from the beginning of a pulse until its end is ______________? - correct answer pulsed duration
d d d d d d d d d d d d d d d d d
, What happens to the speed of sound in a medium when the bulk modulus of the medium increases? - correct
d d d d d d d d d d d d d d d d d d d d
answer faster d
___________ resolution is determined by SPL - correct answer radial or axial
d d d d d d d d d d d
If a wave's amplitude is doubled, what happens to the power? - correct answer quadrupled
d d d d d d d d d d d d d d
Power of sound has units of: - correct answer watts
d d d d d d d d d
If the intensity of a sound beam remains unchanged while the beam area is reduced in half, what has
d d d d d d d d d d d d d d d d d d d
happened to the power? - correct answer halved d d d d d d d
Which of these intensities is the smallest? SATP, SPTP, SATA - correct answer SATA
d d d d d d d d d d d d d
The duty factor for CW ultrasound is: - correct answer 1.0
d d d d d d d d d d
What is the minimum value of the duty factor? - correct answer 0%
d d d d d d d d d d d d
What are the units of intensity? - correct answer watts/cm2
d d d d d d d d d
What happens to the speed of sound in a medium when the bulk modulus of the medium decreases? - correct
d d d d d d d d d d d d d d d d d d d d
answer slower d
The units of attenuation are ______; this is a ______________ scale - correct answer dB, logarithmic
d d d d d d d d d d d d d d d
Sound intensity is decreased by 75%. How many decibels of attenuation is that? - correct answer 6 dB
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The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic frequency? - correct
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answer 5 MHz d d
