Light path and focal length of a concave lens

Principle

The experiment on refraction of light by a concave lens serves, on the one hand, to strengthen the knowledge and experimental skills gained from the experiments with convex lenses. The aim of this experiment is to observe the path of light on passage through a concave lens and determine the focal point and the focal length using the already familiar procedure. On the other hand, a significant difference from the convex lens becomes evident, as the position of the (virtual) focal point is in front of the lens and thus the introduction of the concept 'virtual image' is facilitated.

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

What is the difference between concave and convex lenses? Investigate the light path through a planoconcave lens and determine the focal length.