Principal Rays

with

~Convex Mirror~

The purpose of this lab is to determine and observe the behavior of principal rays incident on a convex mirror.

Ray BoxConvex MirrorLegal Sized PaperPencilRuler

Draw a horizontal straight line with a ruler on the legal sized piece of paper, this will act as your principle axis.

Darken the room as much as possible. Place the convex mirror onto the

principle axis drawn on the sheet of paper.(Be sure to place the mirror on the p.a. in such a way that cuts the mirror into two equal parts.)

Trace the position of the mirror. Take your ray box and change the slit to

allow only one ray of light to be emitted. Place your ray box on the sheet of paper,

directed towards the curved side of the mirror, and trace its position.

At the same position, shine your ray of light towards the focal point (F); which is half the center of curvature, and trace both your incident and reflected rays using a pencil.

At the same position, shine your ray of light parallel to the principal axis. Trace both your incident and reflected rays.

At the same position, shine your ray of light towards the center of curvature; which is half the mirror. Trace both your incident and reflected rays.

In each case, be sure to indicate the direction in with the path of the light travelled.

If needed record your results in a small chart.

Convex mirrors are known as diverging mirrors due to the fact when light is shined towards them, the light reflects outwards, in opposite directions. In contrast concave mirrors, which curve inward, cause reflected rays to converge after reflection. Another aspect of convex mirrors is that they create virtual images, which appear to be smaller, behind the mirror, and upright and reversed. When the light rays are reflected, they can be extended to meet the image position, but do not naturally go through it on their own.

Is parallel to the principle axis: Any incident ray traveling parallel to the

principal axis on the way to the mirror will pass through the focal point upon reflection.

Passes through the focal point: Any incident ray passing through the focal

point on the way to the mirror will travel parallel to the principal axis upon reflection.

Passes through the center of curvature: Rays passing through the center of curvature

of a concave mirror are reflected back along the same path as the incident ray.

Through this experiment, one was able to determine and observe the behavior of principal rays incident on a convex mirror.

It was discovered that when a single ray of light was directed towards the focal point, it would reflect parallel to the principle axis, and when directed parallel to the principle axis, it would reflect from the mirror as though originating from the focal point, and lastly when directed towards the center of curvature, it reflects coincidentally.

Convex mirrors were discovered to have a wide range of view. For that reason, convex mirrors are used worldwide for many purposes and can be found indoors and out. For example, on vehicles and in conjunction with security cameras.