Answer:
The light enters the box along the normal to the side of the box or perpendicularly to the box's surface
Therefore, the light is expected to travel straight through the box
However, when a rectangular glass prism is placed inside the box, the light can then be refracted to pass through the box in the given path as shown
Light bends towards the normal when passing from a less dense medium to a denser medium with larger refractive index and vice versa
Therefore, when the glass prism with a larger refractive index than air is inclined with the top part further away from the incident beam and the bottom part closer to the incident beam as shown, the refracted ray through the box will be shifted downwards as shown in the drawing created with Microsoft Visio
Explanation:
Where;
i = The angle between the incidence light and the normal line
r = The angle between the refracted light and the normal line
n = The refractive index
When n > 1 is large, we have, ∠i > ∠r and the light is bent towards the normal when moving from a less dense medium to a denser medium and vice versa.