Light Waves

Laws of Reflection

1) The incident ray, the reflected ray and the normal , at the point of incidence, are all on the same plane.

2) The angle of incidence is equal to the angle of reflection

Laws of Refraction

1) The incident ray, the refracted ray, and the normal, at the point of incidence, are all on the same plane.

2) The ratio sin i ÷ sin r is constant for a given pair of media where i is the angle of incidence and r is the angle of refraction.

Formula: n= Sin i / Sin r

n= Refractive index

i= angle of incidence

r= angle of refraction

Refractive Index of Travelling Light Speeds

n= speed of light in medium 1 ÷ speed of light in medium 2

Refractive Index of Depth

n= Real depth ÷ apparent depth

Critical Angle (Defination)

The critical angle is defined as the angle of incidence that makes an angle of refraction that is 90° degrees

Critical Angle (Formula)

sin c = 1 / n

c= critical angle

n= refractive index

Total Internal Reflection

Total internal reflection occurs when the angle of incidence is greater than the critical angle for light travelling from a dense to a less dense medium. the ray of light is reflected into the more dense medium.