In this project, students will learn about the properties of light and how they are affected by refraction. They will do this by conducting an experiment to observe the refraction of light through a prism. Students will then use their observations to draw conclusions about the properties of light and the nature of refraction.
Materials
White sheet of paper, Drawing pins, Glass prism, Protractor, Ruler, Two pins, Light source.
Procedure
Fix the white sheet of paper to a drawing board using drawing pins.
Place the glass prism on the paper so that it is resting on its triangular base.
Use a pencil to draw the outline of the prism on the paper.
Draw a normal line (NEN) to the face of the prism AB.
Make an angle between 30° and 60° with the normal.
On the line PE, fix two pins at a distance of 5cm from each other and mark these as P and Q.
Look for the images of the pins at P and Q through the other face of the prism AC.
Use a ruler to draw the path of the light rays from the pins to their images.
Measure the angle of refraction at each of the two faces of the prism.
Observations
Students will observe that the light rays are refracted when they pass through the prism. The angle of refraction will be different for the two faces of the prism.
Conclusions
Based on their observations, students can conclude that light is a wave that travels in a straight line. When light passes from one medium to another, it is refracted. The angle of refraction depends on the speed of light in the two media.
Further Investigations
Students can extend this project by investigating the following questions:
What happens to the angle of refraction if the angle of incidence is increased?
What happens to the angle of refraction if the refractive index of the prism is increased?
How does the color of light affect the angle of refraction?
Assessment
Students can be assessed on their understanding of the properties of light and the nature of refraction by asking them to answer the following questions:
What is light?
How does light travel?
What is refraction?
What factors affect the angle of refraction?
How can refraction be used to explain the phenomenon of rainbows?
Answers & Comments
Project Overview
In this project, students will learn about the properties of light and how they are affected by refraction. They will do this by conducting an experiment to observe the refraction of light through a prism. Students will then use their observations to draw conclusions about the properties of light and the nature of refraction.
Materials
White sheet of paper, Drawing pins, Glass prism, Protractor, Ruler, Two pins, Light source.
Procedure
Observations
Students will observe that the light rays are refracted when they pass through the prism. The angle of refraction will be different for the two faces of the prism.
Conclusions
Based on their observations, students can conclude that light is a wave that travels in a straight line. When light passes from one medium to another, it is refracted. The angle of refraction depends on the speed of light in the two media.
Further Investigations
Students can extend this project by investigating the following questions:
Assessment
Students can be assessed on their understanding of the properties of light and the nature of refraction by asking them to answer the following questions: