Question 15
Refraction of LightIf a ray travelling in air is incident on a transparent medium as shown in the diagram, the refractive index of the medium is given as
- A.cos α/sin β
- B.sin α/sin β
- C.cos β/sin α
- D.sin β/sin α
Show the answer and explanation
Answer: A (cos α/sin β)
Explanation
α is measured from the surface, so the angle of incidence is 90° − α and sin(90° − α) = cos α. β is the angle of refraction, so n = cos α/sin β.