Question

Assertion (A) : A ray passing through the centre of curvature of a concave mirror after reflection, is reflected back along the same path.
Reason (R) : The ray passing through the centre of curvature is incident normally to the mirror.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is not the correct explanation of A.
• C. A is true but R is false.
• D. A is false but R is true.

Answer 1

The correct option is A Both A and R are true and R is the correct explanation of A.


When a light ray passes through the centre of curvature of a concave mirror, it strikes the mirror along the normal of the mirror. The ray incidences on to the mirror along the normal i.e. at an angle of ${90}^{\circ }$ from the mirror.
Therefore, angle of incidence = $0°$
So, as we know according to the law of reflection:
angle of incidence = angle of reflection = $0°$
Thus, the ray of light retraces its path.