(II) A lens appears greenish yellow ( =570 NM is strongest) when white light reflects from it. What minimum thickness of coating (N =1.25) do you think is used on such a glass lens (N =1.52), and why?
Step 1 of 3</p>
The path difference of the rays 1 and 2 reaching the observer from the coating and glass is 2d.
Step 2 of 4</p>
At the minimum thickness of the film; d=0
The path difference is