## Light and Color - Detailed Help

### Assignment LC3: Primary Colors of Light

Objectives:
• The student should be able to explain the meaning of a primary light color and identify the three primary colors of light.
• The student should be able to predict the result of mixing primary colors of light.

The Physics Classroom, Light and Color Unit, Lesson 2, Part d

 The three primary colors of light are ____. Primary Colors of Light: Any three colors (or frequencies) of light which produce white light when combined with the correct intensity are called primary colors of light. The most common set of primary colors is red (R), green (G) and blue (B). White (W) light is produced when red, green and blue light are mixed or added together with equal intensity. Many students of physics suffer a little mental anguish when hearing from their physics teacher what the three primary colors of light are. After all, it doesn't seem to be consistent with what their fifth grade art teacher said. But don't be fooled! Art teachers use paint and speak of the three primary colors of paint. Physics teachers on the other hand are discussing the three primary colors of light. Both teachers are correct; they are just talking about two different topics - paints and light.

 When the three primary colors of light are mixed with equal intensities, the result will be the color ____. Primary Colors of Light: Any three colors (or frequencies) of light which produce white light when combined with the correct intensity are called primary colors of light. The most common set of primary colors is red (R), green (G) and blue (B). White (W) light is produced when red, green and blue light are mixed or added together with equal intensity. Many students of physics suffer a little mental anguish when hearing from their physics teacher that the three primary colors of light mix together to produce white light. After all, it doesn't seem to be consistent with what they experienced in art class. In art class, you mixed primary colors of paints together - and the result wasn't white. But don't be fooled! In physics, we discuss mixing lights together. You haven't done that before (at least you aren't aware of having done it). Your art experience was correct; but that was the mixing of paints. Now you get to learn something new; you get to learn about mixing light.

 White is not really a color. Rather, white can be considered to be ____. Visible Light Light is a form of electromagnetic (EM) radiation. The human eye is sensitive to a narrow range of frequencies within the enormous range which the EM spectrum spans. Visible light itself is a spectrum of frequencies which is often referred to as ROYGBIV. Objects which appear white are reflecting visible light. The whiteness of such light is most often attributed to the presence of all the frequencies of the visible light. ROYGBIV, when present together, results in white light.

 Black is not really a color. Rather, black can be considered to be ____. Visible Light Light is a form of electromagnetic (EM) radiation. The human eye is sensitive to a narrow range of frequencies within the enormous range which the EM spectrum spans. Visible light itself is a spectrum of frequencies which is often referred to as ROYGBIV. Objects which appear white are reflecting visible light. The whiteness of such light is most often attributed to the presence of all the frequencies of the visible light. ROYGBIV, when present together, results in white light. If you walk into a closet and turn the lights off, everything around you is black. Why? Because there is no light in the closet. Without light, the so-called blue jeans cannot reflect blue light to your eyes. Without light, the red and green basketball jersey cannot reflect red and green light to your eye. Your colorful wardrobe is now totally black. Black is the absence of all the colors of the visible light spectrum.

 Determine the result of mixing the following colors of light with equal intensities: Red light mixed with green light produces ____ light. Red light mixed with blue light produces ____ light. Green light mixed with blue light produces ____ light. Red light, green light and blue light mixed together produces ____ light. Enter four letters which fit the blanks in their respective order. Color Addition of Primary Light Colors: Three primary colors of light - most notably, red, green and blue - when mixed together in equal intensity will produce white light. Mixing two primary light colors in equal intensity will produce a third color. Red light mixed with blue light produces magenta light. Blue light mixed with green light produces cyan light. And green light mixed with red light produces yellow light.

 Two lights - a Red light and a Green light - are used to illuminate a white sheet of paper. When these light colors are mixed with equal intensities, the paper will appear ____. Color Addition of Primary Light Colors: Three primary colors of light - most notably, red, green and blue - when mixed together in equal intensity will produce white light. Mixing two primary light colors in equal intensity will produce a third color. Red light mixed with blue light produces magenta light. Blue light mixed with green light produces cyan light. And green light mixed with red light produces yellow light.

 Two lights - a Red light and a Blue light - are used to illuminate a white sheet of paper. When these light colors are mixed with equal intensities, the paper will appear ____. Color Addition of Primary Light Colors: Three primary colors of light - most notably, red, green and blue - when mixed together in equal intensity will produce white light. Mixing two primary light colors in equal intensity will produce a third color. Red light mixed with blue light produces magenta light. Blue light mixed with green light produces cyan light. And green light mixed with red light produces yellow light.

 Two lights - a Green light and a Blue light - are used to illuminate a white sheet of paper. When these light colors are mixed with equal intensities, the paper will appear ____. Color Addition of Primary Light Colors: Three primary colors of light - most notably, red, green and blue - when mixed together in equal intensity will produce white light. Mixing two primary light colors in equal intensity will produce a third color. Red light mixed with blue light produces magenta light. Blue light mixed with green light produces cyan light. And green light mixed with red light produces yellow light.