Exam-style question
Try this first
What happens to light when it hits the boundary of an optical fibre at an angle greater than the critical angle?.
- A.It is refracted into the second medium.
- B.It is absorbed by the fibre.
- C.It is reflected back into the fibre.
- D.It continues to travel in a straight line.
Model answer
What a good answer should say
- It is reflected back into the fibre.
Explanation
Why this works
When light hits the boundary at an angle greater than the critical angle, total internal reflection occurs, causing the light to be reflected back into the optical fibre rather than refracted out.
Common mistake
No common mistake is linked to this question yet.