Refraction

Question 1

Refractive index

Answer 1

Refractive index = c/n or sin i/sin r

Question 2

Critical angle

Answer 2

When the angle of refraction is equal to 90 degrees, the angle of incidence is called the critical angle

Question 3

Total internal reflection

Answer 3

At any angle the incidence greater than the critical angle, the light cannot pass through the surface- it is all reflected. This is called total internal reflection