Disorder in an optics laboratory · Estonian PhO 2011 #1
Physics · optics
Problem
An optician was cleaning an old laboratory and found an unmarked concave lens and a convex lens. To determine their optical powers he positioned the lenses in a straight line and directed two parallel laser rays through them, the distance between the rays was x1=\SI1,0cm. He changed the distance between the lenses until the rays leaving the system were also parallel (he controlled that by determining the distance between them with a sheet of paper at different lengths), now the distance between the rays was x2=\SI26mm. In that situation the distance between the lenses was d=\SI32cm. What was the optical power of the lenses?