​A point on the principal axis which is equidistant from the curved surface of a spherical mirror is:​​

Correct option is A

The correct answer is (A) Centre of curvature

Explanation:

• The centre of curvature of a spherical mirror is the point on the principal axis that is equidistant from the mirror’s curved surface.

• It lies on the principal axis, and its distance from the mirror is equal to the radius of curvature (R).

• The centre of curvature is located on the same side as the reflecting surface for a concave mirror and on the opposite side for a convex mirror.

Information Booster:

• The principal focus (option B) is the point where parallel rays of light either converge or appear to diverge after reflection from the mirror. It is located at a distance half the radius of curvature (R/2) from the mirror’s surface.

• Infinity (option C) is a hypothetical point where parallel rays of light appear to meet after reflection, but it is not a fixed point like the centre of curvature.

• The pole (option D) is the geometrical center of the mirror’s reflecting surface, not equidistant from the curved surface.

Additional Information:

• The distance from the pole to the centre of curvature is equal to the radius of curvature (R).

• The focal point (or focus) is a key concept in optics, and the distance from the pole to the focus is half the radius of curvature (R/2).