Radio waves

Definition

Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. They have frequencies ranging from about 3 kHz to 300 GHz.

5 Must Know Facts For Your Next Test

1. Radio waves are used for wireless communication, including radio, television, and cell phones.
2. They travel at the speed of light in a vacuum, which is approximately $3 \times 10^8$ meters per second.
3. Radio waves can be generated by natural phenomena such as lightning or astronomical objects, as well as by man-made devices like antennas.
4. The wavelength of radio waves ranges from thousands of meters to around one millimeter.
5. Different frequency bands within the radio wave spectrum are allocated for different purposes, such as AM and FM radio or satellite communication.

Review Questions

• What is the frequency range of radio waves?
• Name two applications that use radio waves for communication.
• How do the wavelengths of radio waves compare to those of visible light?

Related terms

Electromagnetic Spectrum: The range of all types of electromagnetic radiation, from gamma rays to radio waves.

Frequency:

The number of oscillations or cycles per second in a wave, measured in Hertz (Hz).

Wavelength:

The distance between successive crests or troughs in a wave, usually measured in meters.