1. Light
Chapter 46

2. Light Light is a form of energy.
Light can do work i.e a solar panel or Crooke’s radiometer.
(Light energy can be
converted to other
forms of energy)

3. Light Luminous objects are a source of light. i.e. The Sun
Non-Luminous objects do not give of their own light.
Non-Luminous objects can be seen because light reflects off them.

4. Luminous vs Non-Luminous

5. Light Light travels in straight lines.
If one piece of card is moved the light can no longer be seen

6. Light
Shadows are formed because light travels in straight lines.

7. White Light
White Light is a mixture of 7 different colours called a spectrum.
Richard
Red Of
Orange
York
Yellow
Gave
Green
Battle
Blue In
Indigo
Vein
Violet

8. White Light The breaking up of white light is called dispersion.
White light can be dispersed using a triangular glass block called a prism.

9. Reflection Reflection – Light bounces back off surfaces.
Light reflects in a regular manner off smooth, shiny, polished surfaces.

10. Reflection
The N is called the normal and is perpendicular to the mirror.
Angle A = Angle B

11. A Periscope A periscope can be used to look around obstacles.
The mirrors are positioned in the periscope at a 45o angle.

12. Refraction
Refraction is the bending of light as it passes from one medium to another.
Note the light ray gets pulled towards the denser substance.
Eg Swimming pool.

13. A Lens
A lens is a piece of glass with a curved surface which is used to bend or refract light.

14. Concave
A concave lens spreads out the rays of light.
Diverging lens

15. Convex A convex lens bends the rays of light together to a point.
Converging lens

16. Uses of Lenses Concave: Convex:
Used in glasses to correct short sighted eyes.
Convex:
Glasses to correct long sighted eyes.
Magnifying glasses.
Telescopes
Cameras
Microscopes