A semi-cylinder made of transparent plastic has a refractive index n = and a radius of R. There is a narrow incident light ray perpendicular to the flat side of the semi cylinder at d distance from the axis of symmetry.
What can the maximum value of d be so that the light ray can still leave the other side of the semi cylinder?
When the value of d chosen is such that TIR just takes place then time for which light remains inside the cylinder is:
Total distance travel in the semi cylinder
Optical path travel
Distance d is now varied, so that the ray always emerges from the other side of the semi cylinder. What is the range of OB?