Waves

• What does the pupil do

  This is an opening that lets light in
• What does the retina do

  Light-sensitive layer at the back of the eye
• What does lens do 


  This focuses light onto the retina.
• What does the cornea do

  Protects the structures in the eye
• Which type of lens is used to

  correct people with long

  sightedness?

  convex lens
• Do convex waves go in or out

  in
• What is the shape used to represent convex waves

  oval
• do concave waves go in or out

  out
• What is the shape used to represent concave waves

  A rectangle that bends inwards
• What type of waves are electromagnetic waves?

  transverse
• Can electromagnetic waves travel through a vacuum?

  yes
• What three types of electro-magnets are dangerous

  ultra-violet, gamma ray, x-ray
• What is the wavelength 


  The distance horizontally between two waves
• What is the first electro magnet in the electro-magnet spectrum

  Radio waves
• what is the second electro magnet in the electro-magnet spectrum

  microwaves
• what is the third electro magnet in the electro-magnet spectrum

  infrared
• what is the fourth electro magnet in the electro-magnet spectrum

  visible light
• What is the 5th electro magnet in the electro-magnet spectrum

  ultra-violet
• what is the 6th electro magnet in the electro-magnet spectrum

  x-ray
• what is the 7th electro magnet in the electro-magnet spectrum

  gamma rays
• What are radio waves used for

  communication
• What are micro waves used for

  communication and cooking
• what are infrared waves used for

  heating
• what is visible light used for

  seeing things
• what are ultra Violet waves used for


  checking bank notes
• What are x-rays used for 


  scanning inside the body
• what are gamma rays used for

  treating cancer
• Light waves change speed when they pass across the boundary between two substances with

  a different density , such as air and glass. This causes them to change direction, an effect

  called refraction. - what is this a description of?


  refraction