What unit is used to measure the intensity, amplitude, and power of an ultrasound wave?

The correct choice for measuring the intensity, amplitude, and power of an ultrasound wave is the decibel. This unit is commonly used in ultrasound physics to express relative differences in intensity levels, which allows for a more manageable way to convey changes in sound intensity. Since ultrasound involves waves that can vary greatly in intensity, using a logarithmic scale (like decibels) helps to express these variations succinctly.

The decibel scale indicates a ratio of power or intensity, making it useful in various fields, including medical imaging, where understanding sound intensity is crucial for safe and effective use of ultrasound technology. For instance, an increase of 10 dB represents a tenfold increase in intensity, enabling clinicians to easily interpret the intensity of sound waves in medical applications.

In contrast, other units such as watts, pascals, and hertz serve different purposes in acoustics and physics. Watts measure power, pascals measure pressure, and hertz measures frequency, which are distinct from the relative intensity and amplitude of ultrasound waves that the decibel measures.