ARDMS Ultrasound Physics &
Instrumentation Practice Exam
Questions & Solutions
Which of the following is defined as only the active time? - ANSWER Pulse duration
The inertia of the medium describes its: - ANSWER Density
Which of the following is determined by the sound source only? - ANSWER Frequency
The prefix "centi" denotes: - ANSWER Hundredths
If the angle of incidence is 40°, what is the angle of transmission at the interface if
medium 1 has a propagation speed of 1320 m/s and medium 2 has a propagation
speed of 1700 m/s? - ANSWER >40°
The change in the direction of the original sound wave that occurs when sound interacts
with two different tissue types that have a different propagation speed is referred to as: -
ANSWER Refraction
Refraction is the change in direction of the transmitted sound beam that occurs with
oblique incidence and dissimilar propagation speeds.
Which of the following is an appropriate unit of measurement for propagation speed? -
ANSWER millimeters per microsecond (mm/μs)
The major component of attenuation is: - ANSWER Pulse repetition frequency
In clinical imaging, the wavelength measures between: - ANSWER 0.1 to 0.8 mm
The duty factor for continuous wave ultrasound is: - ANSWER 100%
All of the following relate to the strength of the sound wave except: - ANSWER
Wavelength
What is the change in intensity if the power decreases by half? - ANSWER Intensity is
halved
Damping of the sound beam: - ANSWER Reduces the spatial pulse length
What is defined as the ability of the ultrasound system to image structures that are
positioned parallel to the sound beam as separate structures? - ANSWER Axial
resolution
Instrumentation Practice Exam
Questions & Solutions
Which of the following is defined as only the active time? - ANSWER Pulse duration
The inertia of the medium describes its: - ANSWER Density
Which of the following is determined by the sound source only? - ANSWER Frequency
The prefix "centi" denotes: - ANSWER Hundredths
If the angle of incidence is 40°, what is the angle of transmission at the interface if
medium 1 has a propagation speed of 1320 m/s and medium 2 has a propagation
speed of 1700 m/s? - ANSWER >40°
The change in the direction of the original sound wave that occurs when sound interacts
with two different tissue types that have a different propagation speed is referred to as: -
ANSWER Refraction
Refraction is the change in direction of the transmitted sound beam that occurs with
oblique incidence and dissimilar propagation speeds.
Which of the following is an appropriate unit of measurement for propagation speed? -
ANSWER millimeters per microsecond (mm/μs)
The major component of attenuation is: - ANSWER Pulse repetition frequency
In clinical imaging, the wavelength measures between: - ANSWER 0.1 to 0.8 mm
The duty factor for continuous wave ultrasound is: - ANSWER 100%
All of the following relate to the strength of the sound wave except: - ANSWER
Wavelength
What is the change in intensity if the power decreases by half? - ANSWER Intensity is
halved
Damping of the sound beam: - ANSWER Reduces the spatial pulse length
What is defined as the ability of the ultrasound system to image structures that are
positioned parallel to the sound beam as separate structures? - ANSWER Axial
resolution
