What is the formula for wavelength in meters?

• A. 300 divided by the frequency in Hz
• B. 3 divided by the frequency in GHz
• C. The frequency in Hz divided by 300
• D. 300 divided by the frequency in MHz

Answer: (D)

Wavelength comes from λ = c / f, where c is the speed of light about 3 × 10^8 m/s. If the frequency is given in megahertz, convert f = f_MHz × 10^6 Hz, so λ = (3 × 10^8) / (f_MHz × 10^6) = 300 / f_MHz. That means the wavelength in meters equals 300 divided by the frequency in MHz.

Why the other forms don’t fit: using 300 as the constant with frequency in Hz would require a different unit basis (the speed of light is 3 × 10^8, not 300), so that yields the wrong magnitude. If frequency is in GHz, the correct form is λ = 0.3 / f_GHz, not 3 / f_GHz, so that option is off by a factor of 10. The 300 divided by frequency in MHz aligns with the unit conversion and gives meters.