Total Internal Reflection in Glass Slab · CAP 2010 #Q7
Physics · optics
Problem
The drawing shows a crown glass slab of refractive index 1.5 with a rectangular cross section. As illustrated, a laser beam strikes the upper surface at an angle of 60°. After reflecting from the upper surface, the beam reflects from the side and bottom surfaces. If the glass is surrounded by air, determine at which point part of the beam first exits the glass.
a) A; b) B; c) C; d) none of the above.
[Figure: Rectangular glass slab with laser beam path showing reflections and exit points A, B, C marked]