Answer to Question #81704 in Classical Mechanics for Aref

Question

by what method can you distinguish between a converging lens and diverging lens?

Answer 1

This method relies on the fact that the paths of light rays through lenses are reversible. If parallel rays enter a converging lens they will converge at the focal point. If rays originate at the focal point and pass through the lens, the rays that emerge will be parallel. If an object is placed at the focal point of a lens and the image is reflected back through the lens, the reflected image will be focused at the same place as the source.