A ray is incident exactly at the critical angle at a denser-to-rarer interface. In geometrical optics, the refracted ray travels:
Options

Question

A ray is incident exactly at the critical angle at a denser-to-rarer interface. In geometrical optics, the refracted ray travels:

G1 Physics · Accepted Answer

At i=C, Snell's law gives r=90°, so the limiting refracted ray is along the interface.