Electromagnetism, Properties Of Waves, Motion, Gases & The Kinetic Theory Worksheet With Answers Page 10
ADVERTISEMENT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36Total internal reflection
(a)
(b)
(c)
This phenomenon occurs when light moves from a more optically dense material (e.g.
water) to a less optically dense material (e.g. air) causing a change in speed.
1. The incident angle θ
is less than the critical angle and so the light ray refracts/
1
bends away from the normal as it emerges from the water. θ
is the angle of refraction.
2
2. The incident angle θ
equal to the critical angle and so the light ray passes along the
1
surface of the boundary.
3. The incident angle is greater than the critical angle and so the light ray is
reflected back into the water. This phenomenon is known as total internal reflection.
θ
= θ
1
2
Uses of total internal reflection.
Optical Fibres: these can be used to carry information by using infra-red light. There are
many uses from internet, cable TV, phone, some signs
Endoscope:An endoscope is any instrument used to look
inside the body. Thousands of optical fibres are bundled
together in an endoscope which is inserted into a human
body by the doctor. Light can be directed down the
fibres even if they are bent, allowing the surgeon to
illuminate the area under observation. He/she can then
view this from a television camera linked to a monitor.
10
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education