ARDMS SPI EXAM STUDY GUIDE 2026
COMPLETE QUESTIONS WITH CORRECT
DETAILED ANSWERS || 100% GUARANTEED
PASS <RECENT VERSION>
Section 1: Ultrasound Principles (10 Questions)
1. Which of the following is an acoustic variable?
A. Intensity
B. Power
C. Pressure
D. Frequency
Explanation: Acoustic variables (pressure, density, temperature, particle motion)
describe the wave's changing state as it propagates. Intensity, power, and frequency
are acoustic parameters that describe the wave's features.
2. The parameter that describes the rate at which energy is transmitted
through a unit area is:
A. Power
B. Amplitude
C. Intensity
D. Wavelength
Explanation: Intensity is specifically defined as the power of the beam divided by
its cross-sectional area, typically measured in watts/cm².
3. What is the primary determinant of the speed of sound in a medium?
A. Frequency
B. Amplitude
C. Density and Stiffness
D. Propagation Path
Explanation: Speed of sound (c) is determined by the medium's density and
stiffness (bulk modulus). Stiffness has a much greater influence. c = √(Bulk
Modulus / Density).
,4. If the frequency of ultrasound is doubled, what happens to the wavelength?
A. It doubles
B. It is halved
C. It remains the same
D. It quadruples
Explanation: The relationship is defined by c = f × λ. Since the speed of sound (c)
is constant for a given medium, if frequency (f) increases, wavelength (λ) must
decrease proportionally.
5. Which of the following media has the highest acoustic impedance?
A. Air
B. Fat
C. Soft Tissue
D. Bone
Explanation: Acoustic impedance (Z) is the product of density and speed of sound
(Z = ρ × c). Bone has both high density and high stiffness, resulting in the highest
impedance among soft tissue media.
6. The percentage of time that the ultrasound system is transmitting a pulse is
called:
A. Pulse Repetition Frequency
B. Spatial Pulse Length
C. Duty Factor
D. Pulse Duration
Explanation: Duty Factor = Pulse Duration / Pulse Repetition Period. It is the
fraction of time the system is "on" and transmitting sound.
7. Which type of wave is used in diagnostic ultrasound?
A. Transverse
B. Longitudinal
C. Surface
D. Torsional
, Explanation: Sound requires a medium and propagates via compression and
rarefaction, which is the definition of a longitudinal wave. Transverse waves (like
light) do not require a medium.
8. The parameter that describes the spatial length of a single pulse is:
A. Pulse Repetition Period
B. Spatial Pulse Length
C. Pulse Duration
D. Cycle Length
Explanation: Spatial Pulse Length (SPL) is the distance a pulse occupies in space.
SPL = Wavelength × Number of Cycles in the Pulse.
9. What is the relationship between propagation speed and the bulk modulus
of a medium?
A. Inversely related
B. Unrelated
C. Directly related
D. Exponentially related
Explanation: Speed of sound increases with the stiffness (bulk modulus) of the
medium. The formula is c = √(Bulk Modulus / Density).
10. If the amplitude of a sound wave is increased by a factor of 3, the power is
increased by a factor of:
A. 3
B. 6
C. 9
D. 1.5
Explanation: Power is proportional to the amplitude squared (P ∝ A²). If
amplitude triples (3), power increases by 3² = 9.
Section 2: Transducers (15 Questions)
11. The piezoelectric effect is:
A. The creation of a magnetic field from an electric current
COMPLETE QUESTIONS WITH CORRECT
DETAILED ANSWERS || 100% GUARANTEED
PASS <RECENT VERSION>
Section 1: Ultrasound Principles (10 Questions)
1. Which of the following is an acoustic variable?
A. Intensity
B. Power
C. Pressure
D. Frequency
Explanation: Acoustic variables (pressure, density, temperature, particle motion)
describe the wave's changing state as it propagates. Intensity, power, and frequency
are acoustic parameters that describe the wave's features.
2. The parameter that describes the rate at which energy is transmitted
through a unit area is:
A. Power
B. Amplitude
C. Intensity
D. Wavelength
Explanation: Intensity is specifically defined as the power of the beam divided by
its cross-sectional area, typically measured in watts/cm².
3. What is the primary determinant of the speed of sound in a medium?
A. Frequency
B. Amplitude
C. Density and Stiffness
D. Propagation Path
Explanation: Speed of sound (c) is determined by the medium's density and
stiffness (bulk modulus). Stiffness has a much greater influence. c = √(Bulk
Modulus / Density).
,4. If the frequency of ultrasound is doubled, what happens to the wavelength?
A. It doubles
B. It is halved
C. It remains the same
D. It quadruples
Explanation: The relationship is defined by c = f × λ. Since the speed of sound (c)
is constant for a given medium, if frequency (f) increases, wavelength (λ) must
decrease proportionally.
5. Which of the following media has the highest acoustic impedance?
A. Air
B. Fat
C. Soft Tissue
D. Bone
Explanation: Acoustic impedance (Z) is the product of density and speed of sound
(Z = ρ × c). Bone has both high density and high stiffness, resulting in the highest
impedance among soft tissue media.
6. The percentage of time that the ultrasound system is transmitting a pulse is
called:
A. Pulse Repetition Frequency
B. Spatial Pulse Length
C. Duty Factor
D. Pulse Duration
Explanation: Duty Factor = Pulse Duration / Pulse Repetition Period. It is the
fraction of time the system is "on" and transmitting sound.
7. Which type of wave is used in diagnostic ultrasound?
A. Transverse
B. Longitudinal
C. Surface
D. Torsional
, Explanation: Sound requires a medium and propagates via compression and
rarefaction, which is the definition of a longitudinal wave. Transverse waves (like
light) do not require a medium.
8. The parameter that describes the spatial length of a single pulse is:
A. Pulse Repetition Period
B. Spatial Pulse Length
C. Pulse Duration
D. Cycle Length
Explanation: Spatial Pulse Length (SPL) is the distance a pulse occupies in space.
SPL = Wavelength × Number of Cycles in the Pulse.
9. What is the relationship between propagation speed and the bulk modulus
of a medium?
A. Inversely related
B. Unrelated
C. Directly related
D. Exponentially related
Explanation: Speed of sound increases with the stiffness (bulk modulus) of the
medium. The formula is c = √(Bulk Modulus / Density).
10. If the amplitude of a sound wave is increased by a factor of 3, the power is
increased by a factor of:
A. 3
B. 6
C. 9
D. 1.5
Explanation: Power is proportional to the amplitude squared (P ∝ A²). If
amplitude triples (3), power increases by 3² = 9.
Section 2: Transducers (15 Questions)
11. The piezoelectric effect is:
A. The creation of a magnetic field from an electric current
