Refraction at a prism

Principle

In this experiment, the students should understand the refraction of light at a prism. At the same time, their understanding of the refraction of light on passing from air to glass or glass to air is strengthened. The splitting of light into colours (colour dispersion) can also be observed in this experiment, but should not be discussed. In the second part of the experiment, the dependence of the angle of internal reflection in a prism on the angle of incidence is demonstrated; an important law which is used in refractometres for the determination of the refractive indices for liquids and solids. The main emphasis in this experiment, in regard to the development of experimental skills, is the precise setting and reading of the angle and the graphical representation of the results. This part of the experiment is therefore substantially more demanding in relation to the abilities and experimental skills required of the students. The two experiments can be seen as a unit. However, each can also be carried out as a separate experiment. For less capable students it is suggested that only the first part of the experiment - observation of refraction at a prism - should be offered.

Benefits

• Multifunctional light box - All-in-one: Can be used for geometric optics on the table, colour mixing and on an optical bench
• Extension with others sets at anytime, no additional light sources needed, recognition value for students

Tasks

How does light travel through a prism?

1. Investigate how light is refracted by a prism.
   
2. Determine the angle of total reflection δ with a prism as a function of the angle of incidence α.