PHYS320(O) iLab Experiment 3

DATA SHEET

Name: __________________ Date: ___________

11 questions @ 2 points each and 2 questions @ 4 points each. 30 points total.

Data

1. Record the distance between the front of the refraction cell and the screen taped to the book here. (2 points)

   d = _____________ cm

2. Use your measurements with water in the refraction cell to complete the table below. (4 points)

1. Paste the graph of sin(q₁) versus sin(q₂) for water with the proportional fit here. (2 points)

2. What is your measured value of the index of refraction of water from the slope of the fit? (2 points)

   n_water = ___________

3. Compare your measured value of the index of refraction of water with the standard value by calculating a percent difference. Show your work. (2 points)

4. Use your measurements with oil in the refraction cell to complete the table below. (4 points)

1. Paste the graph of sin(q₁) versus sin(q₂) for oil with the proportional fit here. (2 points)

2. What is your measured value of the index of refraction of vegetable oil from the slope of the fit? (2 points)

   n_oil = ___________

3. Compare your measured value of the index of refraction of vegetable with the standard value by calculating a percent difference. Show your work. (2 points)

   Questions

4. What are some of the sources of error that could have affected your results? (2 points)

1. One problem with using optical fibers for communication is that light that passes directly down the center of the fiber takes less time to travel from one end to the other than a ray that takes a longer zig-zag path. Light rays that start at the same time but traveling in slightly different directions reach the end of the fiber at different times. This problem can be solved by making the refractive index of the glass gradually change from a higher value in the center to a lower value near the edge. Explain how this reduces the difference in travel times. (2 points)

2. The glass core of an optical fiber has an index of refraction of 1.60. The index of refraction of the cladding surrounding the fiber is 1.48. What is the maximum angle a light ray can make with the wall of the core if it is to remain inside the fiber? Show your work. (2 points)

3. A laser beam in air is incident on a liquid at an angle of 53° with respect to the normal. The laser beam’s angle in the liquid is 35°. What is the liquid’s index of refraction? Show your work. (2 points)