lenses and ray tracing lab

/ - ...... Phys1112: Lenses and Ray Tracing ( 1 ln s Name: j -- Materials: Ray box, converging lenses, screen, lighted object, three stands, meter stick. two letter size white pages, and pencil. Objectives: 1. Understanding real image formation from lenses due to refract ion. 2. Practicing ray tracing for converging and diverging lenses 3. Understanding magnification and using a lens combination to 1 111r, ove magnification Part 1: Ray Tracing l. Draw a long straight line down the middle of a sheet of white paper to be our optical axis. Draw a line perpendicular to the optical axis in the middle of the page to be our lens plane. Take th e thinner converging lens out from the box and place it on a white sheet o/ r<1 11 er as shown below. (DO NOT use the thickest one.) Now use the ray box to produce a single,." ,. . co m ing from th e left side of the lens running parallel to the optical axis. Notice that the ray is re I· , ,I by the lens and changes direction. Trace onto the paper the path of the ray before and :ii . , ;,, in g through the lens and label this as Ray 1. Mark the point where the refracted ray crosses t ,, pt,cal axis with an "F." This point is the right side focal point of the lens. Be careful not to ch :i n gc t he position of the lens on the paper. Left side of the lens Ray 1 Right side of the lens optical axis -----------11111---- -1- --------- Lens plane 2. The shortest distance from the lens plane to th e focal point is called th e focal length. From your ray diagram measure the focal length. f. of the converging lens. Re mov e th e len s to do thi s but put it back in place when done. f= y . '< Remember Units

,:::) 3. Now use a parallel ray coming from the right side of the lens to locate the focal point or th e l cn, on the left side. Also mark this point with an "F." Is the focal length the sa me as you foun d •n Question 2? °' {)~\;- S()~ 4. Send a ray from the left side of the lens through the left side focal p oi nt and i nt o the lens as shown below. Trace the ray onto lhe paper before and after it is refracted by the lens and label it on your paper as Ray 2. 5. After going through the lens, is the refracted Ray 2 parallel to the optical axis? \ \- I) pu'rO.\\<.;\ 6. Send a ray directly through the center of the lens and trace the ray. Label it as Ray 3 on your paper. 7. Summarize ~e behavior of each of these three rays ( called principal rays) after they pass throu gh the converging lens. Ray 1 - a ray parallel to the optical axis 80t\ ~~ijY\\: d \'4 ~1i)(A \\~:\J}VJ,Uj~ ~v ~Cu\ 90,'Yl\= 1 Ray 2 - a ray passing through the front-side focal point ~I ~- ~r-'1. ... 0) ...... _._._I \..., !->-.\._ _____ _ _ ' Ray 3 - a ray passing through the center of the lens gu~, ~\"'± -\v'WiMj"n Q,1~(,_\\u 2