Names:__________________________________________________ Group:_______________
Optics Lab: Reflection, Refraction, and Polarization
DATA and DATA ANALYSIS
Part 1: Reflections
Describe your experimental setup to test the law of reflection and include your data.
Part 2: Snell’s Law
How can you confirm that your optic is set up correctly?
Angle of Incidence
Angle of Refraction ±
n±
*
45⁰
<45⁰=
>45⁰=
* Attach a plot or show your calculation to determine n. Is your graph consistent with Snell’s Law? Explain why or
why not.
Part 3: Internal Reflection
Record any changes in the reflected and transmitted ray as you increase the angle of incidence.
Record the critical angle:
θC = ____________± ______________
Calculate the index of refraction (show your work):
n=___________± ______________
Discussion Questions
Compare your results for the index of refraction with the value of 1.49 for acrylic. Which of
your measurements is the most precise? Which is the most accurate? Why?
Calculate the speed at which light travels inside the acrylic block and compare it to the speed of
light in a vacuum.
What is the largest source of error in the experiment?
How would you improve the experiment in the future?
Extra Problems:
For the drawing below: (a) Find the refractive
indices of material A and B. (b) Find the angle  .
The critical angle of a certain material (say, a piece of glass of unknown refractive index n) in air
(refractive index of air is 1.0) is 400. What is the critical angle of the same glass if it is immersed in water
(refractive index of water is 1.33)?