PASCO OS-8459 Beginning Optics System - Manual (Page 7)

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M o d e l N o . O S - 8 4 5 9 E x p e r i m e n t 1 : C o l o r A d d i t i o n
7
Experiment 1: Color Addition
Purpose
In Part 1 of this experiment, you will discover the results of
mixing red, green, and blue light in different combinations.
In Part 2, you will compare the appearance of red, blue, and
black ink illuminated by red and blue light.
Part 1: Addition of Colored Light
Procedure
1. Turn the wheel on the light source to select the red,
green, and blue color bars. Fold a blank, white sheet of
paper, as shown in Figure 1.1. Lay the paper on a flat
surface and put the light source on it so that the colored
rays are projected along the horizontal part of the paper
and onto the vertical part.
2. Place the convex lens near the ray box so it focuses the rays and causes them to
cross at the vertical part of the paper.
Note: The lens has one flat edge. Place the flat edge on the paper so the lens stands stably
without rocking.
3. What is the resulting color where the three
colors come together? Record your observa-
tion in Table 1.1.
4. Now block the green ray with a pencil.
What color results from adding red and blue
light? Record the result in Table 1.1.
5. Block each color in succession to see the
addition of the other two colors and com-
plete Table 1.1.
Questions
1. Is mixing colored light the same as mixing colored paint? Explain.
2. White light is said to be the mixture of all colors. In this experiment, did mixing
red, green, and blue light result in white? Explain.
Required Equipment from Beginning Optics System
Light Source
Convex Lens from Ray Optics Kit
Other Required Equipment
Red, blue, and black pens
Blank white paper
Folded paper
Convex lens
Light source
Red, green,
and blue rays
Combined
colors
Figure 1.1: Color addition
Table 1.1: Results of Colored Light Addition
Colors Added Resulting Color
red + blue + green
red + blue
red + green
green + blue