Physics 9 Lesson 54: Mixing colored lights
1. Theoretical Summary
1.1. What is mixing colored lights together?
- Two or more colored lights can be mixed together by shining the beams at the same spot on a white screen at the same time. The color of the screen in that is the color that we get when we mix the aforementioned colored lights together.
Two or more colored light beams can be mixed together, shining them simultaneously directly into the eye (these beams must be very weak). Then on the retina of the eye there will be the color that we get.
1.2. Mixing two colored lights together
When you mix two colored lights together, you get a different color light.
When there is absolutely no light, we see darkness, that is, we see black.
1.3. Mix three colored lights together to get white light
Mixing red, green, and blue lights properly will result in white light.
Mixing colors from red to purple together will also get white light.
However, the above-mentioned white lights are slightly different and different from the white light emitted by a lamp or the sun.
The three colors red, green, and blue are called the three primary colors. That’s because if you mix three basic light beams with the appropriate strength and weakness, you will get all colors in nature.
2. Illustrated exercise
Question 1: Make a small circle out of cardboard, on top of white paper paste. Divide the circle into 3 equal parts: a red fill, a green fill, and a blue fill. Make an additional axis of rotation through the center of the circle so that the circle rotates like a gyro. Let the circle spin in daylight. Comment on the color of the paper at that time. Can this be considered an experiment of mixing colored lights together?
This experiment is called the Newton’s round disk experiment. Due to the phenomenon of image retention on the retina of our eyes, if the disc rotates rapidly, each point on the mesh receives almost simultaneously three types of light reflected from the three regions with red and green colors made on the disc. and give the impression of white. This can also be thought of as an experiment of mixing colored lights together.
Verse 2: Cover the three windows with three red, green and blue filters. Where these three light beams meet, what color light is obtained?
When blocking the three windows with three red, green and blue filters, where the three beams above meet, we get white light.
3.1. Essay exercises
Question 1: BILLIONAt a point on a color television screen there are three particles, which emit three different types of light: red, green, and blue. If these three particles are excited to emit light differently, different colors will be produced at that point. If these three colors are strongly stimulated, what color light will appear at that point?
Verse 2: Shining red light with green light, what color light streak can we cultivate?
Question 3: Make a small circle out of cardboard, on a white paper stick in the middle with a rotating shaft, divide the circle into three equal parts and color them in red, green and blue, respectively. Let the circle rotate really fast to look at the paper surface, what color do we see?
Question 4: When two red and green lights are shined on a white sheet of paper, we see a yellow light on the paper. If we add the appropriate blue light to the paper, what color light will we see on the paper?
3.2. Multiple choice exercises
Question 1: Mixing red light with yellow light results in which of the following colors?
Verse 2: Which of the following produces a mixture of colored lights?
A. Shine a beam of red light on a yellow card.
B. Shine a beam of red light through a yellow filter.
C. Shine a beam of white light through a red filter, and then through a yellow filter.
D. Shine a beam of red light and a beam of yellow light onto a white sheet of paper.
Question 3: When mixing the lights of the color below. Which case does not produce white light?
A. Mix red, green, blue light with appropriate brightness.
B. Mix yellow, magenta, yellow, green, blue light with appropriate brightness.
C. Mix yellow and blue light with appropriate brightness.
D. Mix red, orange, yellow, green, blue, indigo, violet light with appropriate brightness.
Question 4: Which of the following is not a mixture of colored lights?
A. Shine the purple light with the yellow light at the same spot on the white curtain. We get light of a different color.
B. Shine red, green, blue light with appropriate strength and weak on the white curtain. We get white light.
C. Shining white light on the recording surface of the CD causes the ray to reflect off the white curtain. We get light of different colors.
D. Shine red, green, and blue light with different strengths and weaknesses on the white curtain, respectively. We in turn obtain light of different colors.
Through this lesson, students will be acquainted with the knowledge related to the Mixing of colored lights along with related exercises in many levels from easy to difficult…, they need to understand:
- Learn how to mix colored lights.
- Know how to mix two colored lights together, three colored lights together to get white light.