question_answer 38)

  A beam of light is incident through the holes on side A and emerges out of the holes on the other face of the box as shown in the figure. Which of the following could be inside the box? (a) Concave lens                                                               (b) Rectangular glass slab (c) Prism                                                              (d) Convex lens

Answer:

                  (D) Since in the diagram all the parallel rays converge at a point. So inside the box there will be a convex lens.