Waves

• Label this image:

  A) Cornea

  B) Pupil

  C) Iris

  D) Lens

  E) Retina

  F) Nerve

  
• What is the function of the pupil?

  This is an opening that lets light in
• What is the function of the retina?

  Light-sensitive layer at the back of the eye
• What is the function of the lens?

  This focuses light onto the retina
• What is the function of the cornea?

  Protects the structures in the eye
• Which type of lens is used to correct people with long sightedness?

  Convex lens
• What type of lens is this?

  Convex lens

  
• What type of lens is this?

  Concave lens

  
• What type of waves are electromagnetic waves?

  Transverse waves
• Can electromagnetic waves travel through a vacuum?

  Yes
• What is the use of radio waves?

  Communication
• Are radio waves dangerous?

  No
• What is the uses of microwaves?

  Communication and cooking
• Are microwaves dangerous?

  No
• What is the use of infrared waves?

  Heating
• Are infrared waves dangerous?

  No
• What is the use of visible light?

  Seeing things/this
• Are visible light waves dangerous?

  No
• What is the use of ultraviolet waves?

  checking bank notes etc
• Are ultraviolet waves dangerous?

  Yes
• What is the use of X-ray waves?


  Scanning inside the body
• Are X-rays waves dangerous?

  Yes
• What is the use of gamma waves?

  Treating cancer
• Are gamma waves dangerous?

  Yes
• Describe refraction:

  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.