Which statement best describes a phased array transducer?

• A. It cannot be used for cardiac imaging
• B. It has a single fixed element
• C. It uses multiple elements to steer the beam electronically
• D. It comprises a small surface area with a flat face

Answer: (C)

The essence of a phased array transducer is that it uses an array of many small elements and controls the timing of their electrical excitation so the emitted waves combine in specific directions. By applying precise delays across the elements, the beam can be steered and focused electronically, without moving the transducer, enabling rapid, sector-shaped imaging typical in cardiac studies.

This capability—electronic steering through multiple elements—is what makes this description the best fit. The other statements miss this key feature: a phased array is not defined by a single fixed element, nor by having a necessarily flat, small face, and it is widely used in cardiac imaging.