Radio waves

• Radio waves are used for communication.
• Radio waves have the longest wavelength and the lowest frequency.
• Radio waves can be generated with electricity (alternating current), because it is made up of oscillating charges.
• Generating radio waves;

  1. A transmitter is connected to an oscilloscope.
  2. The oscilloscope allows us to see the frequency of the alternating current. This is important because it determines the frequency of the wave that will be produced.
  3. Once the radio wave is generated a receiver can detect it. It will absorb the energy from the wave and therefore generate an alternating current.
  4. This alternating current can be displayed on another oscilloscope. The frequency of this alternating current and the first one is exactly the same.
• Types of communication that radio waves are used for;

  • Long wave - transmitted over large distances, because the bend around the curved surface of the earth.
  • Short wave - transmitted over long distances, because they are reflected from the ionosphere.
  • Very short waves - transmitted over short distance, because they have to go directly from transmitter and receiver.