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:
The pole of a concave mirror is the geometric center of the mirror's surface. It is the point where the mirror's reflecting surface intersects the mirror's principal axis. It is denoted by the letter 'P'.

2. Centre of Curvature:
The centre of curvature is the point located on the principal axis of the concave mirror, at a distance equal to the radius of curvature from the mirror. It is the center of the sphere of which the concave mirror is a part. It is denoted by 'C'.

3. Radius of Curvature:
The radius of curvature is the distance between the pole (P) and the centre of curvature (C) of the concave mirror. It is the radius of the spherical surface of which the concave mirror is a part.

4. Principal Axis:
The principal axis is the straight line that passes through the pole (P) and the centre of curvature (C) of the concave mirror. It is the line of symmetry of the mirror and is perpendicular to its surface.