Which one of the following figures correctly shows the path of a ray of light through a glass prism ?
Image of path of light through prism
Image of path of light through prism
Image of path of light through prism
Image of path of light through prism
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-2 – 2021
Assuming Option A depicts the standard correct path of a ray of light through a glass prism. A ray of light entering a prism from air bends towards the normal upon entering the glass (denser medium). Inside the prism, it travels in a straight line. Upon exiting the prism from glass back into air (rarer medium), it bends away from the normal.
According to Snell’s Law, when light travels from a rarer medium (like air) to a denser medium (like glass), the ray bends towards the normal. When it travels from a denser medium to a rarer medium, it bends away from the normal. For a prism, the incident ray bends towards the normal at the first surface and the emergent ray bends away from the normal at the second surface. The net deviation of the ray is always towards the base of the prism for a ray entering one face and exiting another.