Magnification

You have encountered a single convex lens before, and likely used it to focus the sun's rays to burn leaves. This single convex lens is called a magnifying glass, and in this activity, we are going to find out how it works.

Conventions: An image height is positive if it is in the same orientation as the object. An image height is negative if it is inverted with respect to the object. All of our images to this point have been inverted. If you have been paying attention, you will also have noticed that the image height gets smaller as you move away from the focal point.

The magnification (m) of an image can be greater than one. In other words, the size of the image is larger than the actual size of the object. Magnification can also be smaller than one; the image will be smaller than the object. The formula which describes magnification is

• Check the box for Principle rays.

• Check the box for Virtual Image.

Experimentally determine the object distances for which the magnification is positive, negative, greater than one, and less than one. Record distances as greater

than or less than the focal length. Be sure to write your results in your laboratory notebook.