Optical Instruments

Physics 212 Computer Intensive Physics;HO-28(12/9/97)

Start a report file in Word. Be sure to record the name of all group members
and the title of this lab (HO-27) and the date(12/9/97).

Research Task #1:

Lenses

Equipment:Optics bench with supports, Lens holders, Radially-slotted object light
box, Screen, Various lenses, Meter stick

A) Determine the focal length for the three convex lenses that you have.
The focal lengthof a lens is defined as the distance from the center of the lens to
the point where the parallel rays of light are focused to one spot. Measure the
focal length of all the convex lenses. How does the focal length seem to be
related to the lens thickness and/or the curvature of the lens surface?

1. A ray passing through the center of the lens is undeviated.
2. A ray passing parallel to the axis of the lens is bent to pass through the focal
   point.
3. A ray passing through the focal point in front of the lens, is bent to pass parallel
   to the lens axis.