Question

In ray tracing for a spherical mirror, which ray is reflected back on itself?

A None of these
B Incoming ray parallel to the optical axis
C Incoming ray through the focal point
D Incoming ray hitting the center of the mirror

Answer 1

The ray that is reflected back on itself when using ray tracing for a spherical mirror is the one that strikes the mirror at the center of curvature. This is due to the law of reflection which dictates that the angle of incidence is equal to the angle of reflection, both of which are zero in this case.

Step-by-step explanation:

In ray tracing for a spherical mirror, the ray that is reflected back on itself is the incoming ray that strikes the mirror exactly at the center of curvature. According to the law of reflection, a ray that strikes the center of curvature of a spherical mirror (such as a concave or convex mirror) is reflected back along the same line, since the incident angle and the reflected angle are both zero in this scenario.

There are other useful rays in ray tracing for mirrors:

• A ray approaching parallel to the optical axis of a concave converging mirror is reflected through the mirror's focal point on the same side.
• A ray approaching a convex diverging mirror parallel to the optical axis appears to emanate from the focal point behind the mirror.
• A ray approaching a concave converging mirror through its focal point is reflected parallel to the optical axis.
• A ray approaching a convex diverging mirror aiming at the focal point on the opposite side is reflected parallel to the axis.