ARDMS Ultrasound Physics & Instrumentation Practice Exam| 50 QUESTIONS| WITH COMPLETE SOLUTIONS

Which of the following is defined as only the active time? CORRECT ANSWERS: Pulse duration The inertia of the medium describes its: CORRECT ANSWERS: Density Which of the following is determined by the sound source only? CORRECT ANSWERS: Frequency The prefix "centi" denotes: CORRECT ANSWERS: 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? CORRECT ANSWERS: >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: CORRECT ANSWERS: 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? CORRECT ANSWERS: millimeters per microsecond (mm/μs) The major component of attenuation is: CORRECT ANSWERS: Pulse repetition frequency In clinical imaging, the wavelength measures between: CORRECT ANSWERS: 0.1 to 0.8 mm The duty factor for continuous wave ultrasound is: CORRECT ANSWERS: 100% All of the following relate to the strength of the sound wave except: CORRECT ANSWERS: Wavelength What is the change in intensity if the power decreases by half? CORRECT ANSWERS: Intensity is halved Damping of the sound beam: CORRECT ANSWERS: 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? CORRECT ANSWERS: Axial resolution What is defined as the beginning of one pulse to the beginning of the next pulse, and therefore includes both the "on" and "off" time? CORRECT ANSWERS: Pulse repetition period