Radiowaves

• What are radio waves part of?

  Electromagnetic spectrum
• What is the wavelength and frequency of radio waves compared to other electromagnetic waves?

  Longest wavelength and lowest frequency
• What are radio waves made up of?

  Oscillating electric and magnetic fields
• How can we generate radio waves?

  Using electricity in the form of alternating current
• What device is used to generate radio waves?

  Transmitter
• What does an oscilloscope allow us to see?

  The frequency of the alternating current
• Why is frequency important in generating radio waves?

  It determines the frequency of the produced wave
• How is a radio wave detected after generation?

  Using a receiver that generates another alternating current
• What does the receiver display on another oscilloscope?

  The frequency of the generated alternating current
• What is the relationship between the frequencies of the generated and detected waves?

  They are exactly the same
• How can we communicate the number 800 using radio waves?

  By generating a wave of 800 hertz frequency
• What is the main use of radio waves?

  For communication
• What are the three types of radio waves?

  • Long wave
  • Short wave
  • Very short wave
• How far can long wave radio waves be transmitted?

  Huge distances, like London to Singapore
• Why can long wave radio waves travel such long distances?

  They diffract around the Earth's surface
• How do short wave radio signals travel long distances?

  They are reflected from the ionosphere
• What is the ionosphere?

  An electrically charged layer of the atmosphere
• What is one use of short wave radio signals besides long-distance communication?

  Sending data over short distances like Bluetooth
• What are very short radio waves used for?

  TV and FM radio
• Why might you not get a great radio signal in a car?

  Surrounding structures can block direct transmission
• What is the main characteristic of very short radio waves?

  They must travel directly from transmitter to receiver
• What are the differences between long wave, short wave, and very short wave radio waves?

  • Long wave: diffracts around the Earth, long distances
  • Short wave: reflects off the ionosphere, long and short distances
  • Very short wave: direct transmission, used for TV and FM radio