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SPI PHYSICS: (ARDMS SPI) EXAM COMPLETE SUMMARY EXAM
LATEST VERSION QUESTIONS AND ANSWERS 2026 EDITION
SPI Physics: Complete Summary and 250-Question Exam Bank
Sonography Principles and Instrumentation (ARDMS SPI) Exam Review
PART 1: ULTRASOUND PHYSICS FUNDAMENTALS - WAVE PROPERTIES AND
PARAMETERS (Questions 1-30)
Question 1
Ultrasound is defined as sound with a frequency greater than which value?
A) 20 Hz
B) 2,000 Hz
C) 20,000 Hz (20 kHz)
D) 2 MHz
Answer: C
Rationale: Ultrasound is defined as sound with a frequency greater than 20,000 Hz (20
kHz). Audible sound ranges from 20 Hz to 20,000 Hz. Infrasound is below 20 Hz.
Diagnostic ultrasound typically uses frequencies between 2 MHz and 15 MHz, which is
well above the audible range .
Question 2
Frequency and period have what type of relationship?
A) Directly proportional
B) Inverse (reciprocal)
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C) Unrelated
D) Exponentially proportional
Answer: B
Rationale: Frequency and period are reciprocals, having an inverse relationship. As
frequency increases, period decreases, and vice versa. The equation is: Period (sec) =
1/Frequency (Hz) .
Question 3
Which of the following parameters is determined solely by the sound source and
cannot be changed by the sonographer?
A) Amplitude
B) Power
C) Intensity
D) Frequency
Answer: D
Rationale: Frequency is determined by the sound source (the transducer) and cannot
be changed by the sonographer. However, the sonographer can select a different
transducer with a different frequency. Amplitude, power, and intensity can all be
adjusted by the sonographer .
Question 4
If the frequency is increased from 3 MHz to 6 MHz, what will happen to the
wavelength?
A) Doubled
B) Quadrupled
C) Halved
D) Quartered
Answer: C
Rationale: Wavelength and frequency have an inverse relationship. When frequency
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doubles, wavelength halves. The equation is: Wavelength = Propagation Speed /
Frequency .
Question 5
The propagation speed of sound through soft tissue is approximately:
A) 330 m/s
B) 1,540 m/s
C) 3,000 m/s
D) 5,000 m/s
Answer: B
Rationale: The average propagation speed of sound through soft tissue is
approximately 1,540 m/s (1.54 km/s, or 1.54 mm/μs). This value is important for
ultrasound system calculations, particularly when determining distances .
Question 6
Which of the following tissues has the fastest propagation speed?
A) Air
B) Fat
C) Soft tissue
D) Bone
Answer: D
Rationale: Sound travels fastest in solids and slowest in gases. The speed order from
slowest to fastest is: air, fat, soft tissue, bone. The stiffness of the medium increases
propagation speed, while density decreases it .
Question 7
Intensity is defined as:
A) Power/Area
B) Propagation speed/Frequency
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C) Density × Propagation speed
D) Area/Power
Answer: A
Rationale: Intensity is the concentration of energy in a sound beam. The equation is:
Intensity = Power (watts) / Beam Area (cm²). Units are watts/cm² .
Question 8
If the amplitude is doubled, what happens to the intensity?
A) Doubled
B) Halved
C) Quadrupled
D) Quartered
Answer: C
Rationale: Intensity is proportional to amplitude squared. Therefore, if amplitude is
doubled, intensity increases by a factor of four (quadrupled). If amplitude is quartered,
intensity is reduced by a factor of 16 .
Question 9
What is the attenuation coefficient for a 6 MHz transducer imaging at a depth of 4
cm in soft tissue?
A) 0.5 dB/cm
B) 3 dB/cm
C) 6 dB/cm
D) 8 dB/cm
Answer: B
Rationale: The attenuation coefficient in soft tissue is approximately 0.5 dB/cm per
MHz. For a 6 MHz transducer: 6 MHz × 0.5 dB/cm/MHz = 3 dB/cm. Total attenuation for 4
cm depth would be 3 dB/cm × 4 cm = 12 dB .
SPI PHYSICS: (ARDMS SPI) EXAM COMPLETE SUMMARY EXAM
LATEST VERSION QUESTIONS AND ANSWERS 2026 EDITION
SPI Physics: Complete Summary and 250-Question Exam Bank
Sonography Principles and Instrumentation (ARDMS SPI) Exam Review
PART 1: ULTRASOUND PHYSICS FUNDAMENTALS - WAVE PROPERTIES AND
PARAMETERS (Questions 1-30)
Question 1
Ultrasound is defined as sound with a frequency greater than which value?
A) 20 Hz
B) 2,000 Hz
C) 20,000 Hz (20 kHz)
D) 2 MHz
Answer: C
Rationale: Ultrasound is defined as sound with a frequency greater than 20,000 Hz (20
kHz). Audible sound ranges from 20 Hz to 20,000 Hz. Infrasound is below 20 Hz.
Diagnostic ultrasound typically uses frequencies between 2 MHz and 15 MHz, which is
well above the audible range .
Question 2
Frequency and period have what type of relationship?
A) Directly proportional
B) Inverse (reciprocal)
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C) Unrelated
D) Exponentially proportional
Answer: B
Rationale: Frequency and period are reciprocals, having an inverse relationship. As
frequency increases, period decreases, and vice versa. The equation is: Period (sec) =
1/Frequency (Hz) .
Question 3
Which of the following parameters is determined solely by the sound source and
cannot be changed by the sonographer?
A) Amplitude
B) Power
C) Intensity
D) Frequency
Answer: D
Rationale: Frequency is determined by the sound source (the transducer) and cannot
be changed by the sonographer. However, the sonographer can select a different
transducer with a different frequency. Amplitude, power, and intensity can all be
adjusted by the sonographer .
Question 4
If the frequency is increased from 3 MHz to 6 MHz, what will happen to the
wavelength?
A) Doubled
B) Quadrupled
C) Halved
D) Quartered
Answer: C
Rationale: Wavelength and frequency have an inverse relationship. When frequency
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doubles, wavelength halves. The equation is: Wavelength = Propagation Speed /
Frequency .
Question 5
The propagation speed of sound through soft tissue is approximately:
A) 330 m/s
B) 1,540 m/s
C) 3,000 m/s
D) 5,000 m/s
Answer: B
Rationale: The average propagation speed of sound through soft tissue is
approximately 1,540 m/s (1.54 km/s, or 1.54 mm/μs). This value is important for
ultrasound system calculations, particularly when determining distances .
Question 6
Which of the following tissues has the fastest propagation speed?
A) Air
B) Fat
C) Soft tissue
D) Bone
Answer: D
Rationale: Sound travels fastest in solids and slowest in gases. The speed order from
slowest to fastest is: air, fat, soft tissue, bone. The stiffness of the medium increases
propagation speed, while density decreases it .
Question 7
Intensity is defined as:
A) Power/Area
B) Propagation speed/Frequency
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C) Density × Propagation speed
D) Area/Power
Answer: A
Rationale: Intensity is the concentration of energy in a sound beam. The equation is:
Intensity = Power (watts) / Beam Area (cm²). Units are watts/cm² .
Question 8
If the amplitude is doubled, what happens to the intensity?
A) Doubled
B) Halved
C) Quadrupled
D) Quartered
Answer: C
Rationale: Intensity is proportional to amplitude squared. Therefore, if amplitude is
doubled, intensity increases by a factor of four (quadrupled). If amplitude is quartered,
intensity is reduced by a factor of 16 .
Question 9
What is the attenuation coefficient for a 6 MHz transducer imaging at a depth of 4
cm in soft tissue?
A) 0.5 dB/cm
B) 3 dB/cm
C) 6 dB/cm
D) 8 dB/cm
Answer: B
Rationale: The attenuation coefficient in soft tissue is approximately 0.5 dB/cm per
MHz. For a 6 MHz transducer: 6 MHz × 0.5 dB/cm/MHz = 3 dB/cm. Total attenuation for 4
cm depth would be 3 dB/cm × 4 cm = 12 dB .
