Which transducer is described as a compact line of elements about one quarter wavelength wide, operated by applying a voltage with minor time differences, allowing multiple focal zones and steering or shaping pulses?

• A. Linear Phased Array
• B. Linear Sequenced Array
• C. Convex Sequential Array
• D. CW Transducers

Answer: (A)

A linear phased array uses a compact line of small elements and emits signals with tiny time differences between neighboring elements. Those deliberate delays create constructive interference in a chosen direction, so the ultrasound beam can be steered and focused electronically without moving the probe. By adjusting the delays, you can produce multiple focal zones at different depths and shape the pulses to tailor resolution and penetration. This ability to electronically steer and focus is the hallmark of a phased array transducer.

The other options don’t fit because a sequenced array fires elements one after another rather than applying precise, simultaneous delays to steer and focus the beam; a convex sequential array is similar in principle but refers to a curved, sequentially driven arrangement rather than true electronic beamforming; and a continuous-wave transducer transmits constantly for Doppler work rather than forming varied focal zones for imaging.