SNC 2D Optics
Name: ____________________
Partner: ___________________
Refraction Laboratory Activity Part 1: Amount of Refraction
Purpose: To determine how to maximize the amount of refraction (get the most bend)
Materials:
ray box
paper
semicircular Plexiglas prism
ruler
protractor
Procedure:
1.
Aim the ray box (with one slit) so that the light hits the flat side of the prism at the centre. See the diagram.
2. Adjust the incident angle to match those in the table. Measure the refracted angle and record in the chart.
Observations:
Table 1: Incident angle and refracted angle for Plexiglas prism
Incident Angle
Refracted Angle
0o
10o
20o
30o
40o
50o
60o
Analysis & Conclusion:
1.
As the incident angle increased, what happened to the refracted angle? (1 mark)
2. Give an answer to the purpose of this lab. (2 marks)
SNC 2D Optics
Name: ____________________
Partner: ___________________
Refraction Laboratory Activity Part 2: Finding the Index of Refraction
Purpose: To determine the index of refraction for water and oil
Materials:
ray box
semicircular box prism ruler
protractor
paper
Procedure:
1. Fill the prism about 2/3 full with water.
2. Aim the ray box (with one slit) so that the light hits the flat side of the prism at the centre. See the diagram.
3. Adjust the incident angle to match those in the table. Measure the refracted angle and record in the chart.
Accuracy is extremely important!
4. Repeat for the prism filled with oil.
5. Fill in the calculations in the table.
Observations & Analysis:
Table 1: Incident angle and refracted angle for water
Incident Angle
(i)
0o
Refracted Angle
(R)
sini
sinR
sini ÷ sinR
20o
40o
60o
Average sini ÷ sinR
Table 2: Incident angle and refracted angle for oil
Incident Angle
(i)
0o
Refracted Angle
(R)
sini
sinR
20o
40o
60o
Average sini ÷ sinR
sini ÷ sinR
SNC 2D Optics
Name: ____________________
Partner: ___________________
Pre-Analysis
See note-taking sheet on Index of Refraction
Analysis & Conclusion:
1. What does sini ÷ sinR represent?
2. a) How close are your experimental refractive indices to the actual reported values in the literature? You may need
to look these actual values up for water, plastic, and oil. What experimental errors might account for these
differences? Find the % deviation for each medium.
Percent Deviation 
actual value  experiment al value
 100
actual value
b) What could you have done to improve the accuracy of your results?
3. What is the relationship between speed of light in a medium, v, and the refractive index, n, of that medium? Fully
support your conclusion with data from this lab activity.
4. Using your lab data and the formula, n = c ∕ v , what is the speed of light in:
a) water
b) oil
5. Reach ahead: What could we do with the equipment provided to determine the critical angle for water?
SNC 2D Optics
Name: ____________________
Partner: ___________________
6. Consider the following data and answer the questions that follow:
a) In which medium is light travelling the slowest?
b) In which medium is light travelling the fastest?
c) In which medium would light bend the most towards the normal?
d) In which medium will the angle of refraction be the largest? (where medium 1 is air)
e) Complete the following diagrams:
f) Find the speed of light in diamond. Remember: n = c ∕ v
g) Fill in the following blanks:

As n decreases, speed of light __________________.

Light ray bends _________________ from the normal.

Light does not move as fast in ice as it does in air. (n (air) < n (ice)). Angle of refraction is
__________________ in air compared to ice