Concept:Concave mirrors converge parallel light rays to the principal focus. The focal length is half the radius of curvature. Refraction behavior depends on refractive index changes across media.
Explanation:When an object is placed at infinity, rays from it are parallel to the principal axis. These parallel rays reflect from a concave mirror and converge to a single point at the principal focus. The image formed at the focus is highly diminished, real, and inverted. Statement A is correct.
For statement B: A ray parallel to the principal axis, after reflection from a concave mirror, actually converges to the focus—it does not appear to diverge. So B is incorrect.
For statement C: The focal length
f of a spherical mirror is half the radius of curvature
R, i.e.,
f=2R​, not double. Hence C is wrong.
For statement D: When light travels from a rarer medium (lower refractive index) to a denser medium (higher refractive index), it bends towards the normal, not away. So D is wrong.
Thus only statement A is correct.
Answer:A. The image formed by a concave mirror for an object lying at infinity is at the principal focus, highly diminished, real and inverted.
