Lenses & Images

HideShow resource information
  • Created by: Jo Wells
  • Created on: 24-04-13 20:39
View mindmap
  • Lenses & Images
    • converging lens = convex
      • causes parallel rays of light to converge at the principal focus
      • principal focus = where rays meet
    • diverging lens = concave
      • causes parallel rays of light to diverge
      • principal focus = where rays appear to meet up
    • axis of a lens is a line passing through middle of lens
    • is a principal focus either side of lens
      • distance from centre of lens to principal focus = focal length
    • 3 rules for refraction in lenses
      • diverging
        • an incident ray parallel to axis refracts through lens & travels in line with principal focus (appears to have come from principal focus)
        • an incident ray passing through lens towards principal focus refracts through lens & travels parallel to the axis
        • an incident ray passing through centre of lens carries on in same direction
      • converging
        • an incident ray parallel to axis refracts through lens & passes through principal focus on other side
        • an incident ray passing through principal focus refracts through lens & travels parallel to axis
        • an incident ray traveling through centre of lens carries on in same direction
    • real images
      • forms an image on a 'screen'
    • virtual images
      • rays = diverging, so light from object appears to be coming from a completely different place
        • e.g. mirror - face appears to be behind mirror = isn't
        • e.g. magnifying lens - image looks bigger than object is = isn't

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Light and Optics resources »