Babinet's principle, a monochromatic beam of parallel light is incident on a "collimating" hole of diameter x >> A. Point P lies in the geometrical shadow region on a distant screen (Figure a) Two diffracting objects, shown in Figure b, are placed in turn over the collimating hole. Object A is an opaque circle with a hole in it, and B is the "photographic negative" of A. Using superposition concepts, show that the intensity at P is identical for the two diffracting objects A and B.

Screen P. B. (a) (6)