87. A point source of light (λ = 600 nm) is located in front of the diaphragm with a circular aperture of radius r = 2 mm. Determine the distance from the source and to the diaphragm, if the hole opens five Fresnel zones and the distance b from the diaphragm to the observation point is 3 m.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)