Which factor directly enables steering the beam without physically moving the transducer?

• A. Dynamic receive focusing
• B. Phased-array steering
• C. Mechanical steering
• D. Transducer aperture

Answer: (B)

Electronic beam steering is achieved through a phased-array approach: many small elements are fired with precise time delays so the emitted wavefront tilts and the main beam points in a desired direction. This lets you steer the beam to different angles without moving the transducer at all.

Dynamic receive focusing, by contrast, adjusts delays when echoes arrive to focus at a chosen depth, not the transmit direction. Mechanical steering would require physically moving or tilting the probe. The transducer aperture affects beamwidth and resolution and can influence how well the beam can be formed, but it does not by itself steer the beam without moving the probe.

So the capability that directly enables steering the beam without moving the transducer is phased-array steering.