Optics Lab

Optics Lab:

Mirrors and Lenses

Theodore Gotis

Oakton Community College
(revised 7/21/11 J)

I. Introduction and Objectives

II. Equipment Needed

Ray Box Concave Lens Compass

Plane Mirror Convex Lens Protractor

Concave Mirror Prism Ruler

Convex Mirror Water Tray

III. Theory

Ray diagrams

Focal length
Radius of curvature
Law of reflection
Snell’s Law (Refraction)
Total Internal Reflection

IV. Experimental Procedure

A. Plane Mirrors

1. Use a ruler to draw a straight line on one side of a sheet of paper near the center, then draw a perpendicular line through the center of the first line.
2. Line up the front edge of the plane mirror with the straight line so that the perpendicular is at the center of the mirror.

Figure 1: Plane Mirror

Ray Box

Incident Ray Plane Mirror

Concave Mirror ( Perpendicular to the Plane Mirror

Reflected Ray

3. Using the concave mirror from your mirror and lens kit, cover up all but one of the rays coming from the ray box.
4. Now aim this single beam of light at an angle ( between 30(and 60( from the perpendicular to the plane mirror, and trace the incident and reflected beams of light with a pencil.
5. Using a protractor, measure the angle ( between the incident ray and the perpendicular to the plane mirror. Do the same for the reflected ray.
6. Now repeat Steps #4-6 for two more incident beams of light between 10( and 80(

Data Table 1: Plane Mirror

|Angle of Incident Ray |Angle of Reflected Ray |
| | |
| |