Page 2 - Lesson note reflection through spherical mirror

Commonly used terms about Spherical mirrors :-


1. Center of curvature: - The reflecting surface of a spherical mirror forms
a part of a sphere. This sphere has a center. This point is called the
center of curvature of the spherical mirror. It is represented by the letter
C. Please note that the center of curvature is not a part of the mirror. It
lies outside its reflecting surface. The center of curvature of a concave
mirror lies in front of it. However, it lies behind the mirror in case of a
convex mirror as shown above in the figure 2.
2. Radius of curvature: - The radius of the sphere of which the reflecting
surface of a spherical mirror forms a part, is called the radius of
curvature of the mirror. It is represented by the letter R.
3. Pole: - The center of a spherical mirror is called its pole and is
represented by letter P as can be seen in figure 2.
4. Principle axis: - Straight line passing through the pole and the center of
curvature of a spherical mirror is called principle axis of the mirror.
5. Aperture of the mirror: - Portion of the mirror from which reflection of
light actually takes place is called the aperture of the mirror. Aperture of
the mirror actually represents the size of the mirror.

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