Refraction at the boundary between two liquids

Principle

In this experiment, the students have the possibility of deepening their understanding of the law of refraction. By observing the refraction at the boundary between two liquids compared to the refraction at the boundary between air and a liquid, the students learn that refraction is not only a function of one medium but always of the two media forming the boundary.
The qualitative comparison of the different parts of the experiment makes the importance of boundaries between two media clear to the students. A quantitative evaluation makes it possible to work out the relationship between the different (relative) refractive indices. This calculation is carried out in a supplementary problem. It is particularly appropriate for students in the higher classes for deepening their understanding of Snell's law of refraction.
With respect to the experimental skills required, the task is particularly demanding as very small changes in the angles must be observed - especially in the case of refraction at the boundary between water and glycerine. A careful adjustment is therefore particularly necessary in the quantitative evaluation.

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

Why is light refracted at the boundary between two liquids?

1. Measure the angle of refraction as a function of the angle of incidence at the boundary between air and water or air and glycerine.
   
2. Measure the angle of refraction as a function of the angle of incidence at the boundary between water and glycerine.