Reflection of Light by Spherical Mirrors
Spherical mirrors are mirrors with surfaces that form part of a sphere. The reflection of light by these
mirrors obeys
the laws of reflection, which state that:
1. The angle of incidence equals the angle of reflection.
2. The incident ray, reflected ray, and the normal to the surface all lie in the same plane.
Spherical mirrors can be categorized as concave or convex, depending on whether the reflecting
surface is inward or outward.
Key Terminology
1. Pole (P): The center of the mirror's surface.
2. Center of Curvature (C): The center of the sphere from which the mirror segment is cut.
3. Radius of Curvature (R): The radius of the sphere of which the mirror is a part.
4. Principal Axis: The straight line passing through the pole and the center of curvature.
5. Focus (F): The point on the principal axis where parallel rays converge (concave) or appear to
diverge (convex) after reflection.
6. Focal Length (f): The distance between the pole and the focus. It is related to the radius of
curvature as:
f=R/2
Reflection by Concave Mirror
- Shape: The reflecting surface is curved inward.