A spherical mirror converges a beam of light, at a given point on the principal axis. Which of the following statement(s) about the mirror is/are true?

(a)The mirror used is concave

(b)The mirror has positive focal length

(c)The point of convergence is the principal focus of the mirror

Correct option is D

The correct answer is (d) Both (a) and (c)

​following statement

​A: The mirror used is concave:

​A concave mirror converges parallel rays of light to a point on the principal axis.
This statement is true.

​B: The mirror has positive focal length:

​For a concave mirror, the focal length () is negative according to the sign convention in optics (since the focus lies on the same side as the object). This statement is false.

C: The point of convergence is the principal focus of the mirror

The rays converge at the principal focus of the concave mirror, which is defined as the point where light rays parallel to the principal axis meet after reflection.
This statement is true.