Question

_______ is half of the radius of curvature of the mirror

Answer 1

Answer:

The distance PC=radius of curvature R of the mirror. Straight line NBCis the normal to the mirror at the point of incidence B. Thus, for a spherical mirror (both for a concave and for convex), the focal length is half of radius of curvature

Answer 2

The focal length of the mirror is half of its radius of curvature.

• For a spherical mirror, the radius of curvature is defined as the radius of the complete sphere of which the mirror was a part.
• The focal length is defined as the distance between the focus (F) of the mirror and its pole (P). The radius of curvature and the focal length of a spherical mirror are related as-

R = 2f

• When a light ray travelling parallel to the principle axis of the mirror is incident on its surface, it passes through the principle focus of the mirror.