The mechanical transducer contains a single circular disc-shaped active element that is physically moved. Which description best matches this statement?

• A. Single Circular Disc-Shaped
• B. Multiple Rectangular Elements
• C. A Curved Strip Element
• D. A Liquid Crystal Array

Answer: (A)

This is about how a mechanically scanned ultrasound transducer operates. In that design, a single active element—a circular disc—is physically moved to sweep the ultrasound beam. The disc shape is typical because one round piezoelectric element provides a straightforward, movable source that the mechanism can drive to cover the sector or area of interest.

So the description that fits best is the single circular disc-shaped element that is moved. The other possibilities imply different transducer concepts: multiple rectangular elements indicate an array with electronic steering rather than mechanical motion; a curved strip element suggests a different geometric arrangement not used for this mechanical system; a liquid crystal array isn’t a transducer at all—it’s a display material, not the emitting element in ultrasound.