Radio Waves
electromagnetic radiation
a kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously
Electromagnetic Spectrum
the range of wavelengths or frequencies over which electromagnetic radiation extends
radio wave, wave from the portion of the electromagnetic spectrum at lower frequencies than microwaves. The wavelengths of radio waves range from thousands of metres to 30 cm. These correspond to frequencies as low as 3 Hz and as high as 1 gigahertz (109 Hz
Frequency range
Frequency is measured in the unit hertz (Hz), referring to a number of cycles per second. One thousand hertz is referred to as a kilohertz (kHz), 1 million hertz as a megahertz (MHz), and 1 billion hertz as a gigahertz (GHz). The range of the radio spectrum is considered to be 3 kilohertz up to 300 gigahertz
Transverse or longitudinal?
All electromagnetic waves (light waves, microwaves, X-rays, radio waves) are transverse. All sound waves are longitudinal
Interesting Facts
Radio waves have the longest waves on the spectrum, so they have the lowest energy. An MRI machine uses these waves to see tissues and bones up close. Microwaves have long waves and low energy, too. The Doppler-radar images you see on your local weather are made from these
Applications
Mobile Phones
When you talk on a cell phone, your cell phone acts as a transmitter and your voice is carried on radio waves to the person you are calling. Their phone acts as the receiver and converts the signal back into your voice
MRI machine
The strong magnetic field created by the MRI scanner causes the atoms in your body to align in the same direction. Radio waves are then sent from the MRI machine and move these atoms out of the original position. As the radio waves are turned off, the atoms return to their original position and send back radio signals
Radios
Radio works by transmitting and receiving electromagnetic waves. The radio signal is an electronic current moving back and forth very quickly. A transmitter radiates this field outward via an antenna; a receiver then picks up the field and translates it to the sounds heard through the radio
