Behavior of em waves

• What type of waves are electromagnetic waves?

  Transverse waves
• How do reflection and refraction of light affect our perception?

  They explain how people see images, color, and optical illusions
• What are the properties and uses of electromagnetic waves?

  • Electromagnetic waves are transverse waves.
  • They have a wide range of properties and uses.
  • Their behavior varies with frequency.
• What is the unit of frequency?

  Hertz (Hz)
• What happens to electromagnetic waves as frequency increases?

  They become progressively more hazardous
• What are radio waves used for?

  Communication such as broadcasting television and radio
• Why are radio waves ideal for communications?

  They can be transmitted easily through air and do not cause damage when absorbed
• What is a conductor?

  A material that allows charge to move easily through it
• What is an alternating current?

  An electric current that regularly changes its direction and size
• How is information transmitted using radio waves?

  Information is coded into the wave before transmission and decoded upon reception
• What are microwaves used for?

  Cooking food and communications
• What happens to molecules in food when they absorb microwaves?

  Their internal energy increases, causing heating
• What is infrared light used for?

  Electrical heaters, cookers, and thermal imaging cameras
• How does infrared light affect chemical bonds?

  It increases the internal energy of the bonds when absorbed
• Can the human eye see infrared light?

  No, the human eye cannot see infrared light
• What is visible light used for?

  Photography and illumination
• How does fiber optic communication work?

  Coded pulses of light travel through glass fibers from a source to a receiver
• What are the main uses of different types of electromagnetic waves?

  • Radio waves: Communication (TV, radio)
  • Microwaves: Cooking, communication
  • Infrared: Heating, thermal imaging
  • Visible light: Photography, illumination
• What is the heating effect of infrared light?

  It can cause burns to the skin
• What is thermal imaging used for?

  Detecting people in the dark