Refraction of Light
Light · Refraction
Syllabus tag: KCSE | Physics | Form 3 | Topic 22 Refraction of Light
Lesson objectives
By the end of this topic, you should be able to:
- Explain refraction and state the laws of refraction.
- Define and calculate refractive index.
- Explain total internal reflection and critical angle.
- Describe applications including optical fibres, prisms and real and apparent depth.
Summary
Refraction is the bending of light as it passes from one medium into another, caused by a change of speed. Light bends towards the normal entering a denser medium and away on leaving. Snell's law gives n = sin i ÷ sin r. Beyond the critical angle, light is totally internally reflected.