In a Young’s double slit experiment λ = 500 nm, d = 1.0 mm and D = 1.0 m. Find the minimum distance from the central maximum for which the intensity is half of the maximum intensity.
Given, separation between the slits 
The distance between the screen and the slit, 
Wavelength of light, 
.
Let the maximum intensity be 
and the intensity at y be 
.
Given,
therefore, path difference, 
1