When switching from a 2.5 MHz transducer to a 5 MHz transducer, the sound wavelength will:

When switching from a 2.5 MHz transducer to a 5 MHz transducer, the sound wavelength will:

• A. Doubles
• B. Quadruples
• C. Quarters
• D. Halves

Answer: (D)

Wavelength is determined by the speed of sound in the medium divided by the frequency: λ = c / f. In tissue, the speed of sound is about 1540 m/s and stays essentially constant. Doubling the frequency from 2.5 MHz to 5 MHz doubles f, so the wavelength halves. For example, λ at 2.5 MHz is about 0.616 mm, and at 5 MHz it’s about 0.308 mm. So the sound wavelength becomes shorter by a factor of two. Higher frequency also means better axial resolution but less penetration.

Wavelength is determined by the speed of sound in the medium divided by the frequency: λ = c / f. In tissue, the speed of sound is about 1540 m/s and stays essentially constant. Doubling the frequency from 2.5 MHz to 5 MHz doubles f, so the wavelength halves. For example, λ at 2.5 MHz is about 0.616 mm, and at 5 MHz it’s about 0.308 mm. So the sound wavelength becomes shorter by a factor of two. Higher frequency also means better axial resolution but less penetration.