question_answer

ABCD is the plane of glass cube. A horizontal beam of light enters the face AB at the grazing incidence. Show that the angle \[\theta \]which any ray emerging from BC would make with the normal to BC is given by \[\sin \theta =\cot \alpha \] where \[\alpha \]is the critical angle. The greatest value that the refractive index of glass may have if any of the light is to emerge from BC is\[\sqrt{a}\], then value of a is?

Answer:

2.00