ROC Fundamentals Practice Exam 2025 – The All-in-One Guide to Mastering Your Certification!

When light strikes a medium at an angle less than the critical angle, it undergoes refraction rather than total internal reflection. Refraction is the bending of light as it passes from one medium to another, which happens when the angle of incidence is below the critical angle. At this angle, the light partially enters the new medium and changes direction based on the refractive index of both the initial and new mediums. Thus, light is both refracted and some portion is reflected back, but the primary event occurring when the angle is less than the critical angle is refraction into the medium.

In contrast, absorption occurs when light energy is taken in by the medium instead of being transmitted, which does not represent how light behaves at angles less than the critical angle. Scattering refers to the diffusion of light in various directions, typically when it interacts with small particles, which also does not pertain to the angle of incidence with respect to critical angles. The confusion may arise from the nature of reflection, but for angles below the critical angle, the light primarily refracts into the medium rather than being predominantly reflected.