Final answer:
The direction of a reflected ray that is below the imaginary principal axis will generally point upward, adhering to the law of reflection.
Step-by-step explanation:
When considering the reflection of light rays in relation to an imaginary principal axis, the direction of a reflected ray that is below this axis will generally point upward, towards the axis. This is based on the law of reflection, which states that the angle of incidence is equal to the angle of reflection, typically measured from the normal line perpendicular to the surface at the point of incidence.
If a light ray strikes a surface below the principal axis, the reflected ray would travel upwards, making the angle it forms with the normal the same as the angle formed by the incident ray and the normal.