An array transducer provides which advantage?

• A. Pure single-frequency beams
• B. Long pulses for axial resolution
• C. Electronic focusing and steering
• D. Greater dynamic range

Answer: (C)

Electronic focusing and steering is the main concept being tested. An array transducer uses many individual elements, and by applying precise time delays to each element’s excitation, the emitted wavefront can be focused at a chosen depth and steered to different angles without physically moving the probe. This electronic control allows dynamic focusing as the beam travels through tissue, improving lateral resolution across the image and enabling real-time scanning. Other options don’t capture this key advantage: pure single-frequency beams aren’t unique to arrays, longer pulses would actually worsen axial resolution, and dynamic range is largely governed by the receiver and processing rather than the transducer’s array structure.