Total internal reflection and applications
- Light travels a distance x in time t_1 in air and 10x in time t_2 in another denser medium. What is the critical angle for this medium? Answer: 1. sin⁻¹(10t₁/t₂) Refractive index n=c/v , and the critical angle satisfies sin C=1/n=v/c . Speed in air: c=x/t₁ . Speed in the medi... 1
- In total internal reflection when the angle of incidence is equal to the critical angle for the pair of media in contact, what will be angle of refraction ? Answer: 4. 90^° At the critical angle C , Snell's law gives μ₁sin C=μ₂sin r with sin C=μ₂/μ₁ . So sin r=1 and r=90^° : the refracted ray gra... 1