L11 Index of Refraction Activity
How exactly is light refracted when it passes from one medium into another denser
medium?
Materials



Ray box (single slit) or Laser Level
Semi-circular glass prism
Polar co-ordinate graph paper with semi-circular container outline
(attached below).
Procedure
1) Place the semi-circular glass prism on the polar co-ordinate paper.
2) Direct a single incident ray of light at the semicircular along the 70º angle
marked on the protractor.
3) Make sure that the ray passes through the
centre of the flat surface. Measure the angle of
refraction and record it in the table to the right.
4) Repeat the procedure for angles of incidence
of 60, 50, 40, 30, 20, 10, and 0,
recording your observations in the table.
5) The measurements for the angles of refraction
(R) in Pure Water are given on the table.
Angle of
Angle of
Angle of
Incidence Refraction Refraction
(i)
(R) in
(R) in
Water
Glass
70°
45
60°
41
50°
35
40°
29
30°
22
20°
15
10°
7
0°
0
Analysis Questions (Circle any Bold choices.)
1) Compared to water, what is the same about how light refracts into glass?
a) When light travels from air to glass at an angle of incidence greater than 0º,
it is bends (away from / towards) the normal.
b) When light travels from air into glass, as the angle of incidence (i) gets
smaller, the angle of refraction (R)
i) gets greater,
ii) becomes equal,
iii) gets smaller.
c) The incident and refracted rays are always on the (same side / opposite
side), of the normal.
d) The angle of refraction (R) is always
i) greater than the angle of incidence i),
ii) less than the angle of incidence i) ,
iii) equal to the angle of incidence i).
2) Compared to water, what is the same about how light refracts into glass?
For any angle of incidencei), the angle of refraction (R) in gycerol is
i) greater thani) in water,
ii) less than i) in water,
iii) equal to i) in water.
3) Light refracts or bends (more / the same / less) in glass than it does in water.
Material
Vacuum
Air at STP
Water at 20 C
Glycerine
Vegetable Oil
Glasses
Sapphire
Diamond
4) The amount that light bends when
going into a different medium is
called its ______________ __
_________________
Index of
Refraction
1.00000
1.00029
1.33
1.473
1.47
1.52-1.62
1.77
2.417
5) Large index of refractions bend
light (more / the same / less) than
low index of refractions.
6) Draw in the refracted ray relative to water for semi-circular containers filled with
a) Vegetable Oil
b)
Diamond
c) Air
7) The following is a diagram of a one-way mirror. Draw rays on it to show and
explain which person sees the other, and which only sees their own reflection.