Question

Optics Procedure

Needed HOL lab kit equipment:magnifier, ruler Student supplied equipment index card,Styrofoam cups or modeling clay,paper clips,tape,colored pens or pencils,digital camera.Finding the Focal Length of a Lens

1.This part of the lab requires a dimly-lit room with an outside-facing window producing an unobstructed view of a distant object. Best results are obtained on a sunny day.

2.You need something to hold both your magnifier and a screen to project an image on.One possibility is to insert your magnifier into an inverted Styrofoam cup and secure it with tape, then insert a paper clip into another inverted Styrofoam cup (again secured with tape). Another possibility is to use lumps of modeling clay to hold your magnifier and paper clip upright. Once you have the magnifier and paper clip secured,place an index card vertically into the paper clip

.3.Locate a large, distant object outside the window approximately 10 or more meters away, such as a tree, telephone pole, or automobile.Place your lens and screen on a table next to the window,keeping them in line with the distant object and placing the lens between the window and screen.Adjust the position of the index card until a sharp image of the distant object falls on the index card because there are two lenses in the magnifier start with the top image corresponding to the larger lens Measure the distance from the center of them magnifier to the index card, and record this as the focal length find your data table.

4.In your data table,record whether the image formed is real or virtual; magnified, shrunken, or the same size; upright or inverted; closer, further, or the same distance from the lens as the object.

5.Repeat steps 3 and 4 with the smaller lens on the magnifier.Ray Tracing Diagrams

1.Make sure you print out the five blank ray tracing diagrams included in this lab. Each one has a converging lens already drawn into place with points marking the focal length and twice the focal length placed on the lens axis. For an object, a simple stick figure is drawn, which is placed at various distances from the lens.Each diagram is labeled by how far the object is from the lens(greater than 2 f, at 2 f, between 2 f and f, at f,or less than f).

2.For each diagram, sketch the path of two rays using. One ray (which should be colored blue)should be the one that comes off the object and travels parallel to the lens axis before passing through the lens and either converging to pass through the focal point on the other side of the lens from the object(as it is for a converging lens) The other ray(which should be colored red)should be the one that passes through the center of the lens undeviated To ensure that the rays are straight, use the lab kit’s ruler as a straight edge.

3.To determine where an image is formed, locate where the two sketched rays cross. If they do not cross on the other side of the lens, carefully extend the refracted rays back through the lens using a dashed or dotted line to see if they cross elsewhere.

4.Using the crossing of the rays as a guide, sketch the image that is formed of the stick figure in black. In your data table,record whether the image formed is real or virtual; magnified,shrunken, or the same size; upright or inverted; closer, further, or the same distance from the lens as the object. If no image is formed, just write “no image” for the type of image and leave the other entries blank.

5.Take a photograph of the five completed ray tracing diagrams;include your name and date on each diagram

.Physical Science Lab Optics 5 Ray Tracing Diagram

1.Object Distance Is Greater than 2 f

2.Object Distance Is 2 f

3.Object Distance Is Between 2 f and f

4.Object Distance Is f

5.Object Distance Is Less than f 0 Optics Data

Answer 1