Question

Write the definitions of the following terms in the context of a concave mirror:

1. Pole
2. Centre of curvature
3. Radius of curvature
4. Principal axis

Answer 1

1. Pole (P): The geometric center of a concave mirror's surface, where the reflecting surface meets the principal axis.

2. Centre of Curvature (C): The center of the sphere from which the concave mirror is a section. It lies on the principal axis at a distance equal to the radius of curvature from the pole.

3. Radius of Curvature: The distance from the pole (P) to the centre of curvature (C). This is also the radius of the spherical surface of which the mirror is a part.

4. Principal Axis: The straight line connecting the pole (P) and the centre of curvature (C). It is the mirror's axis of symmetry and is perpendicular to its surface.