ARDMS Ultrasound Physics & Instrumentation Practice Exam 2026 - Free Ultrasound Practice Questions and Study Guide

The term that describes the distance between two successive peaks in a wave is wavelength. Wavelength is a fundamental concept in wave mechanics and is defined as the spatial period of a wave—the distance it takes for the wave to complete one full cycle, which includes traveling from one peak to the next peak (or from one trough to the next trough).

In the context of ultrasound and other types of waves, understanding wavelength is essential, as it influences how the waves interact with tissues and also affects the resolution and penetration of the ultrasound imaging. Longer wavelengths tend to penetrate tissues more effectively but may provide lower resolution, while shorter wavelengths offer better resolution but do not penetrate as deeply.

The other options provided refer to different wave characteristics. Frequency refers to the number of cycles per second of a wave and is inversely related to wavelength while amplitude measures the strength or intensity of the wave, indicating its height from a baseline to a peak. Velocity, on the other hand, is the speed at which the wave travels through a medium and is determined by both wavelength and frequency. However, none of these definitions correspond to the distance between two successive peaks, which is why the correct choice is wavelength.