A laser beam travels in acrylic ((n=1.49) ) and enters crown glass ((n=1.52) ) at 25°…
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Geometric Optics · Geometric Optics
Problem
A laser beam travels in acrylic (n=1.49) and enters crown glass (n=1.52) at 25° from the normal. Which of the following qualitatively characterizes the behavior of the beam as it crosses the boundary?
(a) It bends slightly away from the normal because the glass has the higher index.
(b) Its direction is essentially unchanged since the two indices differ by less than 3%.
(c) It bends slightly toward the normal because the glass has the higher index.
(d) It reflects back into the acrylic because the incident angle exceeds the critical angle for the interface.