LIGHT  Made by –  TUSHAR GOYAL
Light                  In this unit:1) Properties of light2) Mirrors3) Colors
1 – Properties of LightLight travels in straight lines:Laser
Light travels VERY FAST – around    300,000 kilometres per second.At this speed it cango around the world 8times in one se...
Light travels much faster than sound. For example: 1) Thunder and lightning    start at the same time,    but we will see ...
We see things because they reflect light into our eyes:            Homework
ShadowsShadows are places where light is “blocked”:                        Rays of light
Properties of Light summary1) Light travels in straight lines2) Light travels much faster than sound3) We see things becau...
ReflectionReal Image – – Real image is formed when   reflected rays of light actually   meet at a point. – Always inverted...
ReflectionVirtual Image–  – “Not Real” because it cannot    be projected  – Image only seems to be there!
Virtual Images in Plane                                                             Mirrors                               ...
Plane Mirror    •Useful to think in terms of images“real” you                                          “image” you
LEFT- RIGHT REVERSAL
Spherical MirrorsSpherical mirrors have a central axis (a radius ofthe sphere) and a center of curvature (the centerof the...
Convex Mirrors      • Curves outward      • Reduces images      • Virtual images   –Use: Rear view mirrors    etc.CAUTION!...
Convex Lenses Thicker in the centerthan edges.   – Lens that     converges (brings     together) light      The Magnifier ...
Concave LensesLenses that arethicker at the edgesand thinner in thecenter.  – Diverges light     The De-Magnifier    rays ...
ColourWhite light is not a single colour; it is made up of a mixture of the seven colours of the rainbow.We can demonstrat...
The colours of the rainbow:                        Red                       Orange                       Yellow          ...
Adding colours  White light can be split up to make separate colours.   These colours can be added together again.  The pr...
Seeing colourThe colour an object appears depends on the colours  of light it reflects.For example, a red book only reflec...
A pair of purple trousers would reflect purple light(and red and blue, as purple is made up of red and blue):             ...
Thank You
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  • Optics: Reflection, Refraction 05/25/2006 Lecture 16
  • Optics: Reflection, Refraction 05/25/2006 Lecture 16
  • Light presentation

    1. 1. LIGHT Made by – TUSHAR GOYAL
    2. 2. Light In this unit:1) Properties of light2) Mirrors3) Colors
    3. 3. 1 – Properties of LightLight travels in straight lines:Laser
    4. 4. Light travels VERY FAST – around 300,000 kilometres per second.At this speed it cango around the world 8times in one second.
    5. 5. Light travels much faster than sound. For example: 1) Thunder and lightning start at the same time, but we will see the lightning first. 2) When a starting pistol is fired we see the smoke first and then hear the bang.
    6. 6. We see things because they reflect light into our eyes: Homework
    7. 7. ShadowsShadows are places where light is “blocked”: Rays of light
    8. 8. Properties of Light summary1) Light travels in straight lines2) Light travels much faster than sound3) We see things because they reflect light into our eyes4) Shadows are formed when light is blocked by an object
    9. 9. ReflectionReal Image – – Real image is formed when reflected rays of light actually meet at a point. – Always inverted. – It is formed on the screen.
    10. 10. ReflectionVirtual Image– – “Not Real” because it cannot be projected – Image only seems to be there!
    11. 11. Virtual Images in Plane                                       Mirrors   Rays seem to come from behind   the mirror, but, of course, they dont.  It is virtually as if the rays were coming from behind the mirror. "Virtually":  the same as if As far as the eye-brain system is concerned, the effect is the same as would occur if the mirror were absent and the chess piece were actually located at the spot labeled "virtual If light energy doesnt flow from the image". image, the image is "virtual".
    12. 12. Plane Mirror •Useful to think in terms of images“real” you “image” you
    13. 13. LEFT- RIGHT REVERSAL
    14. 14. Spherical MirrorsSpherical mirrors have a central axis (a radius ofthe sphere) and a center of curvature (the centerof the sphere).
    15. 15. Convex Mirrors • Curves outward • Reduces images • Virtual images –Use: Rear view mirrors etc.CAUTION! Objects are closer thanthey appear!
    16. 16. Convex Lenses Thicker in the centerthan edges. – Lens that converges (brings together) light The Magnifier rays. – Forms real images and virtual images depending on position of the object
    17. 17. Concave LensesLenses that arethicker at the edgesand thinner in thecenter. – Diverges light The De-Magnifier rays – All images are erect and reduced.
    18. 18. ColourWhite light is not a single colour; it is made up of a mixture of the seven colours of the rainbow.We can demonstrate this bysplitting white light with aprism:This is how rainbows areformed: sunlight is “split up”by raindrops.
    19. 19. The colours of the rainbow: Red Orange Yellow Green Blue Indigo Violet
    20. 20. Adding colours White light can be split up to make separate colours. These colours can be added together again. The primary colours of light are red, blue and green:Adding blue and red Adding blue andmakes magenta green makes cyan(purple) (light blue)Adding red Adding alland green three makesmakes yellow white again
    21. 21. Seeing colourThe colour an object appears depends on the colours of light it reflects.For example, a red book only reflects red light: White Only red light light is reflected
    22. 22. A pair of purple trousers would reflect purple light(and red and blue, as purple is made up of red and blue): Purple light A white hat would reflect all seven colours: White light
    23. 23. Thank You

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