Балкански 2007, Теория — Задача 4. An exercice in optics

Concours Général de Physiques “Minko Balkanski” — 20 mai 2007 · 20 май 2007 г.

Указания

The two exercices are independent.

All the answers must be given in English or in French*. The clarity and the precision will be taken into account for the final note.*

The exam is 4 hours long.

Условие

An exercice in optics

Two right-angled triangular prisms joined along a common vertical side: the left prism (n1) has a 30° apex angle at the top and its right angle at the bottom; the right prism (n2) has its right angle at the top and a 45° angle at the bottom. A horizontal arrow labelled “ray of ligth” enters the slanted left face, and a horizontal arrow leaves the slanted right face in the same direction.

Two triangular prisms, with angles 30∘30^{\circ} and 45∘45^{\circ} are disposed as in the figure above. A ray of light, that is parallel to the prisms basis, is entering the system, and is leaving in the same direction. What is the refractive index n2n_2 of the 45∘45^{\circ} prism if the refractive index of the 30∘30^{\circ} prism is equal to n1=2.1n_1 = 2.1 ? We recall the trigonometric identity :

sin⁡(α−β)=sin⁡(α)cos⁡(β)−sin⁡(β)cos⁡(α)(5)\sin(\alpha - \beta) = \sin(\alpha)\cos(\beta) - \sin(\beta)\cos(\alpha) \qquad (5)

FIN

Решение

Внимание: Непълно решение

В архива няма официално решение на тази задача.

Оригинал в Архива: CGP_2007_en.pdf