What is the wavelength for a 1 MHz ultrasound wave?

What is the wavelength for a 1 MHz ultrasound wave?

• A. 1.54 mm
• B. 0.154 mm
• C. 15.4 mm
• D. 1540 mm

Answer: (A)

Wavelength is found by dividing the speed of sound by the frequency: λ = c / f. In soft tissue, c is about 1540 m/s. For a 1 MHz wave (1,000,000 Hz), λ = 1540 / 1,000,000 = 0.00154 m, which is 1.54 mm. The other numbers would correspond to different frequencies (for example, a much higher or lower frequency would yield different wavelengths), so 1.54 mm is the wavelength for a 1 MHz ultrasound wave in tissue.

Wavelength is found by dividing the speed of sound by the frequency: λ = c / f. In soft tissue, c is about 1540 m/s. For a 1 MHz wave (1,000,000 Hz), λ = 1540 / 1,000,000 = 0.00154 m, which is 1.54 mm. The other numbers would correspond to different frequencies (for example, a much higher or lower frequency would yield different wavelengths), so 1.54 mm is the wavelength for a 1 MHz ultrasound wave in tissue.