Reflection and refraction

• What does the law of reflection state?


  Angle of incidence = angle of reflection
• Where are the angle of incidence and reflection measured between?


  The light ray and normal (imaginary line at 90 degrees)
• What is a spectacular reflection?

  Reflection from a smooth, flat surface.
• What happens to the image in a spectacular reflection?

  Image is upright and virtual
• What happens in a virtual image?

  The rays diverge from behind the mirror, so the image appears to come behind from the mirror
• What is diffuse reflection?

  If a surface is rough it will occur. The reflected light is scattered in all directions which may cause a distorted image
• What is refraction?


  The change in direction of a wave
• What can refractions cause?

  Optical illusions as the light waves appear to come from a different position to their actual source
• The density of a material affects the..

  Speed of the wave
• The denser the transparent material..


  The more slowly light travels through it
• In refraction, if the ray meets the boundary at an angle to the normal..


  It bends towards the normal
• If the ray hits the block at an angle..

  It’s speed and direction changes. The ray is bent back to its original direction when it leaves the block
• FAST=? (In terms of speed and direction of light)

  Faster - Away Slower- Towards
• If a wave slows down, what happens to its wavelength?


  It will decrease
• When the wave slows down,the frequency remains the same due to..


  The wavelength being shorter