Using the soft tissue rule (1.54 mm divided by frequency in MHz), what is the wavelength at 2 MHz?

Using the soft tissue rule (1.54 mm divided by frequency in MHz), what is the wavelength at 2 MHz?

• A. 1.54 mm
• B. 3.08 mm
• C. 0.77 mm
• D. 7.7 mm

Answer: (C)

In soft tissue, wavelength and frequency are linked by λ = v / f, where the speed of sound v is about 1540 m/s. For practical teaching, this becomes λ (mm) ≈ 1.54 / f (MHz). At 2 MHz, the wavelength is 1.54 / 2 = 0.77 mm. So the wavelength is 0.77 mm. The other numbers would correspond to different frequencies (for example, 1.54 mm at 1 MHz, 3.08 mm at 0.5 MHz, and 7.7 mm at 0.2 MHz).

In soft tissue, wavelength and frequency are linked by λ = v / f, where the speed of sound v is about 1540 m/s. For practical teaching, this becomes λ (mm) ≈ 1.54 / f (MHz). At 2 MHz, the wavelength is 1.54 / 2 = 0.77 mm. So the wavelength is 0.77 mm. The other numbers would correspond to different frequencies (for example, 1.54 mm at 1 MHz, 3.08 mm at 0.5 MHz, and 7.7 mm at 0.2 MHz).