### PW 4 - Refraction of Light B

```Particles and Waves
CfE Higher
PW 4 - Refraction of Light B
1. The diagram shows the ray traced by a pupil investigating the refraction of
red light using a glass semi-circular block.
A
N
(a) Calculate the refractive index of the glass material
for red light.
.
26
o
(3)
O
(b) (i) Calculate the critical angle of the glass for red
light.
40o
(3)
(ii) Draw a diagram to show the path of the ray if the
angle AON is increased to 44o.
Clearly mark all the relevant angles.
2. A ray of red light travels from air into glass as shown.
Calculate the critical angle for the glass.
(2)
glass
air
(4)
25o
40
o
3. If the refractive index of this prism is 1.20, calculate:
a) angle θA (angle of refraction) if angle in air is 30°.
(3)
b) angle θB (angle of refraction) if angle in air is 44°.
(3)
4. The refractive index for diamond is 2.42.
(a) What is meant by the term ‘critical angle’?
(1)
(b) Calculate the critical angle for diamond.
(3)
(c) What effect will the value calculated for the critical angle of diamond
have on the beauty of a well cut stone?
(2)
(d) Copy and complete the following diagrams to show the paths of the
rays of light between the diamond to air interface.
Add the relevant angles to each of the diagrams.
(ii)
(i)
Air
(iii)
Air
Diamond
(3)
Air
Diamond
Diamond
29.4
o
o
24.4
19.4
o
5. A block of glass, which has a refractive index of 1.53 for red light is
designed as shown below.
PN is a ray of red light incident at N, the mid-point of WZ.
X
W
60o
50o
P
N
Z
Y
Draw a full size diagram of the glass block and complete the path of the
ray of light until it emerges from the block. Show all calculations and
mark all relevant angles on the diagram.
(6)
Total Marks = 33
```