What is the wavelength at 5 MHz given speed 1540 m/s?

What is the wavelength at 5 MHz given speed 1540 m/s?

• A. 0.308 mm
• B. 0.154 mm
• C. 0.615 mm
• D. 1.54 mm

Answer: (A)

Wavelength comes from dividing how fast the wave travels by how often it repeats. Use λ = v / f. Here, v = 1540 m/s and f = 5 MHz = 5,000,000 Hz. So λ = 1540 / 5,000,000 = 0.000308 m, which is 0.308 mm. The other options would imply different frequencies: 0.154 mm would need about 10 MHz, 0.615 mm about 2.5 MHz, and 1.54 mm about 1 MHz, not 5 MHz.

Wavelength comes from dividing how fast the wave travels by how often it repeats. Use λ = v / f. Here, v = 1540 m/s and f = 5 MHz = 5,000,000 Hz. So λ = 1540 / 5,000,000 = 0.000308 m, which is 0.308 mm.

The other options would imply different frequencies: 0.154 mm would need about 10 MHz, 0.615 mm about 2.5 MHz, and 1.54 mm about 1 MHz, not 5 MHz.