A beam of parallel light rays is incident through the holes on one side of a box and emerges out through the holes on its opposite side as shown in the diagram below:Which of the following could be inside the box?(a) a rectangular glass block(b) a concave lens(c) a convex lens (d) a glass prism"

(c) a convex lens

Explanation

The beam of light is converging at a point when it is coming out through the holes of the box, therefore, there should be a convex lens inside the box.

Converging Lens or Convex Lens $-$ It is a lens that possesses at least one surface that curves outwards. In other words, it is thick across the middle and thin at the upper and lower edges, because of which the light that enters the lens, gets focused, or converged. Due to this effect, it is also known as a positive lens or a converging lens.

The image formed by a convex lens is both real and virtual depending on the position of the object, which means both diminished and magnified images can be produced.