P3.1.4 - Your Hospital 2 (Refraction)

Question 1

How do Doctors look inside a patients digestive system?

Answer 1

They use an endoscope

Question 2

The glass fibre that allows an endoscope to work is called an…

Answer 2

optical fibre

Question 3

What is refraction?

Answer 3

Where light bends as it passes from one material and into another e.g. air into glass

Question 4

Light can travel down optical fibres even if the fibres are bent into curves or circles. Describe in detail how this happens.

Answer 4

1. Light travels in straight lines
2. The angle between the light hitting a surface and the normal is the angle of incidence
3. If the angle of incidence is smaller than the critical angle the beam is refracted.
4. If the angle is bigger than the critical angle the beam is totally internally reflected.
5. In an optical fibre the light always hits at an angle bigger than the critical angle
6. So light travels down the tube even if it is curved (while still travelling in straight lines)