Question

The critical angle is the angle of incidence in the denser medium for which the angle of refraction in the rarer medium is:

Options

• \[0^\circ\]

• \[180^\circ\]

• \[45^\circ\]

• \[90^\circ\]

Answer 1

The critical angle is defined as the angle of incidence in the denser medium for which the angle of refraction in the rarer medium becomes exactly \[90^\circ\]. At this point, the refracted ray travels along the interface between the two media.