Which component is described as undergoing compression and rarefaction to generate waves?

Which component is described as undergoing compression and rarefaction to generate waves?

• A. Crystal
• B. Transducer housing
• C. Gel
• D. Air gap

Answer: (A)

The piezoelectric crystal inside the transducer is the element that does this. When driven by an alternating electrical signal, the crystal repeatedly expands and contracts, producing compression and rarefaction in the surrounding medium. Those pressure fluctuations propagate as ultrasonic waves into the body. The transducer housing just holds things in place, the gel serves as the coupling medium to improve energy transfer, and an air gap would block or reflect sound rather than generate waves.

The piezoelectric crystal inside the transducer is the element that does this. When driven by an alternating electrical signal, the crystal repeatedly expands and contracts, producing compression and rarefaction in the surrounding medium. Those pressure fluctuations propagate as ultrasonic waves into the body. The transducer housing just holds things in place, the gel serves as the coupling medium to improve energy transfer, and an air gap would block or reflect sound rather than generate waves.