Reflection & Refraction of Light Objective: The objectives of this lab activities are: To study the law of reflection and refraction of light using different media . To study the phenomenon and condition of total internal reflection . To observe the dispersion of light by prism and refraction of light by different kinds of lens Introduction: The law of reflection of light states that when light bounces off of a surface, the angle of reflection (Or) is always equal to the angle of incidence (@;). Additionally, the incident ray, reflected ray, and normal all lie in the same plane. O; Or Angle of Angle of incidence reflection Incident ray Normal Reflected ray MirrorThe law of refraction of light states that, when a ray of light passes from one medium to another medium, light bends towards or away from the normal. when a light ray passes from a medium to a denser medium, light rays bend toward the normal because the light slows down. When light rays pass from a medium to a less dense medium, they bend away from the normal because the light speeds up. The Snell's law for refraction is given by: Angle of incidence Angle of refraction n1 sine, = n: sin 02 Where, n1 is the refractive index of one medium and lls the angle of incidence. Similarly, n2 is the refractive index of another medium and 92 is the angle of refraction. red orange yellow green blue violet dispersion colours of the rainbow when a ray of white light passes through a prism, It is separated Into its component colors. This separation of visible light Into colors ls known as dispersion. . Be sure to watch the Tips & Pointers video In Canvas. . Go to htt s: het.colorado.edu en simulation ndln -|i ht and open the Bending Light Slm. Click on Intro. . Press the red button to turn on the laser, which passes from one medium to another. . Move the protractor and position it to measure Incident angles. reflected angles, and refracted angles. . For each scenario select the top and bottom materials as specified. . Record the Index of refraction, n, for each material. . Set the laser to each incident angle and record the reected or refracted angles In the table. . After filing In the table, draw two of the rays as they are shown In the slm. . The example below shows an angle of Incidence of 55". an angle of reection of 55, and an angle of refraction of 38*. THE [AW OF REFLECTION Top Material: Air Top Index of Refraction (n1): Bottom Material: Water Bottom Index of Refraction (n1): 1. Based on each listed angle of incidence predict the angle of reection and record it. Be sure to read the Introduction on page 1. 2. Then adjust the laser to each angle of incidence and use the protractor to measure the angle of reection. Predicted Observed Reflected Angle Reected Angle Incident Angle 3. Draw the ray diagram here for two different incident angles. The diagrams will appear just like the red lines in the simulator. THE LAW OF REFRACTION Top Material: Air Top Index of Refraction (n1): Bottom Material: Water Bottom Index of Refraction (nz): 1. Based on each listed angle of incidence predict the angle of refraction and record it. Use the equation: n, sin 01 = n2 sin 02 Use the equation to predict for 02 = sin 1(" * sin 01) Example Trial 1: 02 = sin. [(1 / 1.33) sin 10] = 7.50 2. Then adjust the laser to each angle of incidence and use the protractor to measure the angle of reflection. Predicted Trials Incident Angle Observed Refracted Angle Refracted Angle (0 1) (02) (02) 1 10 7.5 2 25 3 45 4 60 5 80 3. Draw the ray diagrams here for two different incident angles.REFRACTION #2 Top Material: Air Top Index of Refraction (mi: Bottom Material: Glass Bottom Index of Refraction (m): 1. Based on each listed angle of incidence predict the angle of refraction and record it. Use the equation: a; sin 0; = n; 3111 02 Use the equation to predict for 02 = sin'1( * sin 01) 2. Then adjust the laser to each angle of incidence and use the protractor to measure the angle of reection. Predicted Observed Refracted Angle Refracted Angle Incident Angle [9 1) 3. Draw the ray diagrams here for two different incident angles. REFRACTION #3 Top Material: Water Top Index of Refraction (m): Bottom Material: Air Bottom Index of Refraction (n2): 1. Based on each listed angle of Incidence predict the angle of refraction and record It. Use the equation: :11 sin 0, = rs; sin 03 Use the equation to predict for 02 = sln"( % t sin 01) 2. h'hen adjust the laser to each angle of incidence and use the protractor to measure the angle of reection. Predicted Observed Refracted Angle Refracted Angle lncldent Angle l01) 3. Draw the ray diagrams here for two different incident angles. REFRACTION #4 Top Material: Glass Top Index of Refraction (ni): Bottom Material: Air Bottom Index of Refraction (nz): 1. Based on each listed angle of incidence predict the angle of refraction and record it. Use the equation: n, sin 01 = n2 sin 02 Use the equation to predict for 02 = sin 1(" * sin 0,) 2. Then adjust the laser to each angle of incidence and use the protractor to measure the angle of reflection. Incident Angle Predicted Observed Trials Refracted Angle Refracted Angle (01) (02 (02) 10 20 3 30 45 5 60 3. Draw the ray diagrams here for two different incident angles.TOTAL INTERNAL REFLECTION 1) Set the top and bottom material according to the data table below. 2) Adjust the laser to an angle of incidence so that light gets refracted and passes from one medium to another medium with a refracted angle of 90. 3) Use the equation: n, sin 0, = n2 sin 02 Then, 01 = sin 1( "2 * sin 02) When you let 62= 90%, the corresponding value for @ is called the critical angle (c). When the incident angle is greater than the critical angle, the ray undergoes total internal reflection. 4) Use the formula above to calculate and record the predicted critical angle for each combination of materials. 5) Then use the protractor and measure and record the observed critical angle. Predicted Observed Top Bottom Critical Angle Critical Angle Material Material (0 c) (0 c) Glass Air Glass Water Water Air Question: Is it possible for total internal reflection to occur if the light passes from air into glass or water, why or why not