What is the term for the speed at which ultrasonic waves travel through a material?

• A. Pulse repetition rate
• B. Ultrasonic response
• C. Velocity
• D. Pulse recovery rate

Answer: (C)

The speed of ultrasonic waves through a material is called velocity. It represents how fast the wavefront travels, typically measured in meters per second, and is essential for time-of-flight calculations used in flaw sizing and material characterization. The other terms refer to how often pulses are emitted (pulse repetition rate) or are not standard descriptors of wave speed, so they don’t describe the actual travel speed.