A narrow beam of light emerges from the base of a thin glass prism toward the denser…
PHYSICS · Single correct · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments
Problem
A narrow beam of light emerges from the base of a thin glass prism toward the denser side of the base. Which of the following best explains this behaviour?
(a) Light bends toward the base because glass has a lower refractive index than air, so the ray is refracted away from the normal at the first surface.
(b) Light bends toward the base because the ray undergoes total internal reflection near the apex and is redirected downward inside the prism.
(c) Light bends toward the base because the incident angle at the first surface is larger than the refracted angle, so the ray is bent toward the normal inside the prism.
(d) Light bends toward the base because dispersion spreads the colours differently and their combined path appears shifted downward.