Physics 9 Lesson 57: Practice Recognizing monochrome and non-monochromatic light with a CD
1. Theoretical Summary
1.1. Experiment purpose
- Knowledge: Answer what is monochromatic light, what is non-monochromatic light.
- Skills: Know how to use a CD to recognize monochromatic and non-monochromatic light.
- Attitude: Know how to work independently to conduct experiments with results.
1.2. Laboratory instruments
A lamp with a filament placed in a lampshade, which can be covered with different colored filters (or after lights).
A set of red, yellow, green, blue filters, LEDs, Laser pens
1.3. Theoretical basis
– Monochromatic light: has a certain color, cannot be decomposed into light of another color.
Non-monochromatic light: has a certain color but can be decomposed into other colored light.
– There are many ways to analyze light: prism, CD.
– Before practice, they learn how to mix the colors of the TV.
So: What color light can be analyzed into other colors by a prism or a CD?
2. Practice report
2.1. Answer the question
a) What is monochromatic light?
Monochromatic light is light that has a certain color and cannot be broken down into lights of other colors.
b) What is non-monochromatic light?
Non-monochromatic light also has a certain color, but it is a mixture of many colored lights; so we can decompose non-monochromatic light into many different colored light.
c) Demonstrate how to recognize monochromatic or non-monochromatic light using a CD
– Shine the light to be analyzed on the recording side of the CD (if there is no CD, a circular stamp can be used on the back of the textbook of the Education Publishing House). Observe reflected light. The disc surface needs to be tilted back and forth to change the angle of incidence of the light beam on the disc surface. Note that only the light to be analyzed (no other light) is allowed to shine on the plate surface.
- If you see the reflected light of only a certain color, then the light hitting the CD is monochromatic light
- If it is detected in the reflected light that there are different colored lights, the light hitting the CD is non-monochromatic.
a) The color of the lights is analyzed from the colored lights produced by different color filters
b) General conclusions about monochromatic or non-monochromatic color light produced by color filters
The light hitting the CD is monochromatic light.
Through this lesson, students will be acquainted with the knowledge related to Practice: Recognizing monochromatic and non-monochrome light by CD along with related exercises in many levels from easy to difficult…, You need to understand:
- Answer the question of what is monochromatic light and non-monochromatic light.
- Know how to use a CD to recognize monochromatic and non-monochromatic light.