Question

Consider sunlight incident on a pinhole of width `10^(3)Å`. The image of the pinhole seen on a screen shall be
A. a sharp white ring
B. different from a geomatrical image
C. a diffused central spot, white in colour
D. diffused coloured region around a sharp central white spot

Answer 1

Correct Answer - B::D
As width of pinhole is `10^(3) A = 1000 Å` and wavelength of sunlight ranges from `4000 Å` to `8000 Å`, therefore, sunlight is diffracted on passing through the pin hole. The image of the pinhole seen on the screen shall be different from a geometrical image. Infact, the image of pinhole will consists of a diffused coloured region around a sharp central white spot. The choice (b) and (d) are correct.