Lab 8[5815]

Geometrical Optics (Experimental Procedure and Data Analysis) This part of the lab must be completed entirely independently of your lab partner(s) or other students. Make sure that you avoid unauthorized collaboration and plagiarism. All suspected violations of the Standards of Conduct will be referred to Student Judicial Affairs. Lab Section (Day & Time): Tuendau 12y o o Name: WUV ICANA Station #: 4 Part 1. Color Addition In the first part of the lab we will discover the results of mixing red, green and blue light in different combinations with the tools shown in Figure 6. Figure 3 1. Plug the light source adapter into an electrical outlet and turn the wheel on the light source to select the red, green, and blue color bars. 2. Place the convex lens at center of the optics ray table, so it converges the rays and causes them to cross. You should see on the screen the image of three distinct colors, similar to the one shown in Figure 3. 3. Now, gently move the screen to/from the lens until (R} the three colors converge into one narrow vertical line on the screen. Question 1: What color appears on the screen at this crossing point? 4. Now block the red ray with a pencil. Question 2: What color results from adding green and blue light? 5. Now block the green ray with a pencil. Question 3: What color results from adding red and blue light? NA 6. Now block the blue ray with a pencil. Question 4: What color results from adding red and green light?

Gl tment Physics 132 | ra where the refracted light is now at 8, = 90°. This incident angle has reached the critical angle 6. - the point beyond which we have total internal reflection, and no refracted light escapes from the acrylic. 16. Measure the angle 6, at which the total internal reflection occurs. Repeat measurement several times by rotating the prism either clockwise or counterclockwise and record the results in Table 3. Table 3 17. Use LibreOffice Calc to estimate the average values of the 6., Mcyic and its M| S ~ c i | uncertainties, and record the results below. # | (in degrees) | Cy 7 ~ 2 1 ! 0, = AR, 72 + 0.7 Thaylic =LA + 0.01% 1 ay Question 8: Does the mcryic value agree with your findings in step 13 and with the | 2 | 4% accepted value within error? Briefly discuss the main sources of error in 3—T ug } measuring the index of refraction in this section. T volug aanee osta ouwn \indineys k) _i_._ AW . \ & » 5 5 o Sowteeh 4 enon T vaeanwning the e L e i 3 . nenacion e\ ,}3 \?,‘M\ \o staot\ o\ ex ak o, 5 ) [+ Q Part 4. Convex and Concave Lenses In this part we will explore the difference between convex and concave lenses. When parallel light rays pass through a thin lens, they emerge either converging or diverging. The point where the converging rays (or their extensions) cross is the focal point of the lens. The focal length, f, of the lens is the distance from the center of the lens to the focal point, F (see Figure 2). If the rays diverge, the focal lens is negative. 18. Place the lapboard on top of the optics ray table and cover it with a white sheet of paper. Plug in the power cable and turn the wheel to select three parallel rays. 19. Place the flat edge of the convex lens on the white paper so that it stands stably and shine the rays straight into the lens. Question 9: Are the outgoing rays converging, diverging or parallel? Estimate the focal length of the lens. \V! 9] 2314 ff«-,’"‘jfi'h\n_ 7 8] Focallenatia = \W.5 v 9 20. Replace the convex lens with concave lens and shine the rays straight into the lens. Question 10: Are the outgoing rays converging, diverging or parallel? Estimate the focal length of the lens. Is it positive or negative? ) nows ong. Avenaing . T locol \emat § R \eve & &FH e \ Y ) (8] J J AN} ‘) Geometrical Optics Page 4 of 4