Radiowaves

• What are radio waves part of?

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

  They have the 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?

  A 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
• What device is used to detect radio waves?

  A receiver
• What does a receiver do with the energy it absorbs?

  Generates another alternating current
• How does the frequency of the alternating current produced by the receiver compare to the original frequency?

  It is exactly the same as the original frequency
• How can we communicate the number 800 using radio waves?

  By generating a wave with a frequency of 800 hertz
• 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 from London to Singapore
• Why can long wave radio waves travel such long distances?

  They diffract around the curved surface of the earth
• How do short wave radio signals travel long distances?

  They are reflected from the ionosphere
• 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?

  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 key point about the frequency of the alternating current produced by the receiver?

  It matches the frequency used to generate the radio wave
• What is the process of transferring information using radio waves?

  1. Generate a radio wave with a specific frequency
  2. Use a receiver to detect the wave
  3. The receiver produces an alternating current of the same frequency
  4. Information is interpreted based on the frequency