The document discusses different types of light sources including incandescent, fluorescent, phosphorescent, chemiluminescent, and bioluminescent sources. It also covers the nature of light as electromagnetic waves and properties of reflection including the laws of reflection and the formation of virtual images in plane mirrors. Concave and convex mirrors are introduced along with their focal points and the formation of real and virtual images depending on the object's position relative to the focal point and center of curvature.

1. Optics Unit Summary<br />Chapter 10 Light and Reflection<br />10.1 Sources and Nature of Light<br />Sources of Light<br />639381573025white light: light from hot objects is made up of many different colours mixed together. <br />incandescence: light emitted from a material because of the high temperature of the material.<br />6188710141605<br />How does an incandescent light bulb work?<br />An incandescent light bulb has a tiny tungsten wire that gets very hot and glows brightly when electric current runs through it. <br />6345555166370electric discharge: the process of emitting light by heating a gas, or vapour, instead of a wire with an electric current.<br />607506689175<br />fluorescence: light that is emitted during exposure of the source to UV (ultra violet) light.<br />There are two types of light: <br />luminous: objects that emit their own light (sun)

2. non-luminous: objects that do not emit light (flashlight that is switched off)luminescence: the emission of light by a material or an object that has not been heated. <br />Types of luminescence<br />fluorescence

3. phosphorescence

4. chemiluminescence

5. bioluminescence