8 LESSON_Q2

• Reflection


  The bouncing back of light when it hits a surface/barrier
• Refraction


  The bending of light when it passes a boundary from a different medium. The bending of light is caused by the change of speed and wavelength due to the difference of material's density. Longer time for light to travel in a material with greater density.
• Diffraction


  The spreading of light when it enters a (slit)small opening of a material as it bends and spreads out
• Interference


  The meeting or union of light from two different slits that may either interfere constructively or destructively depending on their relative phase differences
• Polarization


  The light made to vibrate in one direction using a polaroid sheet where embedded crystals are aligned in a particular direction
• Two of the properties will only be the focused of study in this module. These are REFLECTION AND REFRACTION
• Specular or regular reflection


  A reflection of light on smooth surfaces like mirrors or a calm body of water
• Diffuse or irregular reflection


  A reflection of light on rough surfaces like clothing,paper and many others
• Types of mirrors


  • Plane mirror
  • Curved mirror
  • Concave
  • Convex
• Light rays hit a concave mirror


  Light rays will converge
• Light rays hit a convex mirror


  Light rays will diverge
• Image formed by plane mirror

  Erect or upright
• Image formed by convex mirror

  Erect or upright
• Polarization


  Light made to vibrate in one direction using a polaroid sheet where embedded crystals are aligned in a particular direction
• Properties focused on in this module

  • Reflection
  • Refraction
• Reflection


  The bouncing back of light when it hits a surface
• Types of reflection


  • Specular or regular reflection
  • Diffuse or irregular reflection
• Types of mirrors


  • Plane mirror
  • Concave mirror
  • Convex mirror
• Light rays hit a concave mirror


  Light rays converge
• Light rays hit a convex mirror


  Light rays diverge
• Plane mirror image


  • Erect or upright
  • Same size and distance of the object
  • Always virtual image
• Concave mirror image


  • Inverted
  • Usually bigger
  • Image distance depends on object's distance from the mirror
  • Always virtual rays
  • Real rays, but when an object is placed in between the vertex and F it will produce virtual rays causing virtual image
• Convex mirror image


  • Erect or upright
  • Always smaller than the actual object
  • Always virtual
• Nature of images formed by converging and diverging mirrors

  • Location of object
  • Location of image
  • Kind of image
  • Position of image
  • Size of image
• Refraction


  The bending of light when it passes two different media
• The cause of the bending of light is when it passes into two different media with different densities that cause light to change its speed and wavelength
• Light passes from a less dense to a denser medium

  The angle of incidence is greater than the angle of refraction
• Light travels from air into water

  It slows down, causing it to change direction slightly
• Mirage


  • A common natural occurrence which is an example of Atmospheric Refraction
• Types of lenses


  • Convex
  • Concave
• Light hits a convex lens


  Light rays converge
• Light hits a concave lens


  Light rays diverge
• Nature of image formed by lenses

  • Location of Object
  • Location
  • Orientation (upright or inverted)
  • Size (reduced or enlarged)
  • Type (real or virtual)
• Lenses have changed the way we perceive our surroundings
• Without lenses, we will not be able to see at all. Our eyes contain lenses that help us see.
• Cornea


  Transparent outer membrane which forms the outer coating of the eye and serves as the "window" of the eye
• Lens


  Jelly-like assembly of tiny transparent fibers that bends light rays that enter the eye
• Iris


  Colored part of the eye that controls the size of the pupil
• Pupil


  Allows light to pass into the eyes from the aqueous humour to the lens
• Ciliary muscle


  Contracts and expands to control the curvature of the lens