Wavelength is defined as the distance over which one complete cycle occurs.

Wavelength is defined as the distance over which one complete cycle occurs.

• A. Duty factor
• B. Pulse duration
• C. Wavelength
• D. Spatial pulse length

Answer: (C)

Wavelength is the distance one complete cycle occupies in space. In a medium, this distance comes from the wave’s speed divided by its frequency: λ = c / f. So higher frequency waves have shorter distances per cycle, while faster media yield longer distances per cycle. For soft tissue, about 1540 m/s, a 2 MHz wave has a wavelength around 0.77 mm, and a 5 MHz wave around 0.31 mm. The other terms refer to different ideas: duty factor is the fraction of time the pulse is on, pulse duration is how long the pulse lasts in time, and spatial pulse length is the total distance the pulse travels during its duration (the number of cycles in the pulse times the wavelength). Hence, the distance per cycle is the defining feature of wavelength.

Wavelength is the distance one complete cycle occupies in space. In a medium, this distance comes from the wave’s speed divided by its frequency: λ = c / f. So higher frequency waves have shorter distances per cycle, while faster media yield longer distances per cycle. For soft tissue, about 1540 m/s, a 2 MHz wave has a wavelength around 0.77 mm, and a 5 MHz wave around 0.31 mm. The other terms refer to different ideas: duty factor is the fraction of time the pulse is on, pulse duration is how long the pulse lasts in time, and spatial pulse length is the total distance the pulse travels during its duration (the number of cycles in the pulse times the wavelength). Hence, the distance per cycle is the defining feature of wavelength.