What is the wavelength of a radio wave at a frequency of 30 MHz?

What is the wavelength of a radio wave at a frequency of 30 MHz?

• A. 10 meters
• B. 1 meter
• C. 3 meters
• D. 30 meters

Answer: (A)

Wavelength is found from lambda = c / f, where c is the speed of light. With c ≈ 3.0 × 10^8 m/s and f = 30 MHz = 3.0 × 10^7 Hz, lambda = (3.0 × 10^8) / (3.0 × 10^7) = 10 meters. So the 30 MHz radio wave has a 10-meter wavelength. For reference, a 1-meter wavelength corresponds to about 300 MHz, a 3-meter wavelength to about 100 MHz, and a 30-meter wavelength to about 10 MHz.

Wavelength is found from lambda = c / f, where c is the speed of light. With c ≈ 3.0 × 10^8 m/s and f = 30 MHz = 3.0 × 10^7 Hz, lambda = (3.0 × 10^8) / (3.0 × 10^7) = 10 meters. So the 30 MHz radio wave has a 10-meter wavelength. For reference, a 1-meter wavelength corresponds to about 300 MHz, a 3-meter wavelength to about 100 MHz, and a 30-meter wavelength to about 10 MHz.