ARDMS Ultrasound Physics & Instrumentation Practice Exam 2025 - Free Ultrasound Practice Questions and Study Guide

The relationship between frequency and wavelength is governed by the wave equation, which states that the speed of a wave is equal to the frequency multiplied by the wavelength. This can be expressed in the formula:

\[ \text{Speed} = \text{Frequency} \times \text{Wavelength} \]

For electromagnetic waves, including ultrasound, the speed in a given medium is a constant. Consequently, if the frequency of the wave increases, the wavelength must decrease in order to maintain the constant speed of sound or light in that medium. This inverse relationship is crucial in ultrasound physics because it highlights how changes in frequency affect the characteristics of the wave.

As an example, in medical ultrasound, higher frequency sound waves provide better resolution images but penetrate less deeply into tissues due to their shorter wavelengths. Conversely, lower frequency sound waves penetrate more deeply but result in lower resolution. Thus, the correct answer illustrates the fundamental principle that as frequency increases, wavelength decreases.