REVISION REFRACTION

The throwing back of light, by a surface, without absorbing it. REFLECTION The throwing back of light, by a surface, without absorbing it.

LAWS OF REFLECTION The incident ray, the reflected ray and the normal are in the same plane The angle of incidence equals the angle of reflection

REFRACTION When a ray passes from one optical medium to another optical medium (at an angle) it will change direction

REFRACTIVE INDEX OPTICAL DENSITY The ratio of the speed of light in a vacuum to the speed of light in a medium (no unit) OPTICAL DENSITY A measure of the speed of light through a medium The higher the optical density, the higher the refractive index

The throwing back of light, by a surface, without absorbing it. REFLECTION The throwing back of light, by a surface, without absorbing it.

TOTAL INTERNAL REFLECTION The reflection of light on the inside surface of an optical dense medium CONDITIONS Must move from more optically dense to less optically dense Angle of incidence must be larger than the critical angle

CRITICAL ANGLE It's a special angle specific to each medium (usually given) The critical angle is the angle of incidence when the angle of refraction is 90o

THREE OPTIONS Angle of incidence < critical angle

Refractive index of medium 1 Refractive index of medium 2 SNELL’S LAW Refractive index of medium 1 Refractive index of medium 2 Angle of incidence Angle of refraction

SNELL’S LAW Surface 1 Surface 2

SNELL’S LAW BLOCK AIR