Reflection of Light Definition of Reflection Types of

Reflection of Light Definition of Reflection Types of Reflection Laws of Reflection Plane Mirrors Total Internal Reflection

Reflection of Light The bouncing off of light as it hits a surface

Important Terms • Incident Ray – Light ray that hits a surface • Reflected Ray – Light ray that bounces off the surface • Normal – Line that is perpendicular to the reflecting surface

incident ray normal reflected ray mirror

Important Terms • Angle of incidence – Angle between the normal and the incident ray • Angle of reflection – Angle between the normal and the reflected ray

incident ray Angle of incidence Angle of reflection normal reflected ray mirror

Types of Reflection • Regular Reflection – a. k. a. specular reflection – When parallel rays are reflected parallel – Reflecting surface is smooth

Regular Reflection

Types of Reflection • Irregular Reflection – a. k. a. diffuse reflection – When parallel rays are reflected in different directions – Reflecting surface is not perfectly smooth

Irregular Reflection

Laws of Reflection #1 The angle of incidence equals the angle of reflection.

Laws of Reflection #2 The incident ray, the reflected ray and normal all lie in the same plane. This means they can all be drawn on a flat sheet of paper.

Ray Diagrams for Plane Mirrors

Ray Diagrams for Plane Mirrors

Ray Diagrams for Plane Mirrors

Ray Diagrams for Plane Mirrors Lateral inversion Left and right are interchanged !

Properties of the Image • Object distance equals image distance • Same size • Laterally inverted • Virtual

Uses of Reflection • Reflectors for bikes and roads

Uses of Reflection • Reflectors for photography

Uses of Reflection • Rear-view mirrors

Uses of Reflection • Medical mirrors • Telescopes

In refraction, some light are reflected

Total Internal Reflection (TIR) When a ray does not cross the boundary but is reflected instead

Fibre Optics

Endoscope