Experiment 12


1. Straight Line Propagation of Light:  In steps 1 and 2 of the Procedure, explain your observations in terms of the straight-line propagation of light. Include a diagram showing how the width of the slit images depends on the orientation of the Light Bulb filament with respect to the Slit Plate.

2. Law of Reflection:  In step 7 of the Procedure, determine the relationship between the angle of incidence and the angle of reflection, and answer Question 7.

3. Law of Refraction:  Using the data obtained in step 14 of the Procedure, construct a graph with sin θr on the x-axis, and sin θi on the y-axis for each incident angle. The Data Table has 2 additional columns for you to enter these data and select them. Use the Excel Chart Maker to make this plot.

4.  Click on any one of the data points.

5.  Record the slope of the best straight line through the data, and enter the value in cell D87. The result is the index of refraction for the acrylic plastic that the lens is made of.

6.  Look up the value of the index for plastic in a handbook and record the value in cell D89. Compute the percentage error between your measurement and the accepted value, and enter it in cell D91.