Beam steering is achieved _______ without any moving parts in the transducer.

• A. Electronically
• B. Mechanically
• C. Magnetically
• D. Thermally

Answer: (A)

Beam steering without moving parts is achieved electronically. In a phased-array transducer, each element is driven with a carefully controlled time delay (and sometimes amplitude). By delaying the signals across the array, the emitted waves interfere constructively in a specific direction, steering the beam without any physical movement of the transducer. This electronic control also enables rapid focusing and steering across different angles. Mechanical steering would require physically moving the transducer, while magnetic or thermal methods don’t provide the practical, rapid beam control used in ultrasound.