question_answer 32)

  Which of the following can make a parallel beam of light when light from a point source is incident on it? (a) Concave mirror as well as convex lens (b) Convex mirror as well as concave lens (c) Two plane mirrors placed at 90° to each other (d) Concave mirror as well as concave lens

Answer:

                    (A) A ray passing through the principal focus of a concave mirror or convex tens, after reflection/refraction, will emerge parallel to the principal axis.