Question1
The rhinestones in costume jewellery are glass with index of refraction 1.50. To compose them more reflective, they are regularly coated with a layer of silicon monoxide of index of refraction 2.00. What is the least coating thickness required to ensure that light of wavelength 560 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference?
Question2
Two converging lenses are placed 30.5 apart. The focal length of the lens on the right is 15.0, and the focal length of the lens on the left is 10.5. An object is placed to the left of 10.5 focal-length lens. A final image from both lenses is inverted and located halfway between the two lenses. How far to the left of the 10.5 focal-length lens is an original object?