1.

Floaters. The oaters you see when viewing a bright, featureless background are diffraction patterns created by defects in the vitreous humor. Sighting through a pinhole sharpens the diffraction pattern, making the oaters more easily seen. If you also view a small circular dot through the pinhole, you can approximate the defect's size. Assume that the oater (defect) diffracts light as a circular aperture does, with the size of the defect being equal to the diameter of the circular aperture. Adjust the dot's distance L from your eye (or eye lens) until the dot and the defect appear to have the same size in your view. That is, until they have the same diameter D1 on the retina at distance L1 = 1.5 cm from the front of the eye, as suggested in Figure (0). Assume that the wavelength of visible light is A = 500 nm. If the dot has diameter D = 1.5 mm and is distance L = 50 cm from the eye and the defect is x = 4.0 mm in front of the retina as in Figure (b), what is the diameter of the defect? Eye . . Circular lens Retina Retina dot Defect 1 "D E '31 '5' 2 1 i T bx ng I' L -ll (a) (b) 71d The gure gives the parameterB of equation = sin 6versus the sine of the angle 9 in a two-slit interference experiment using light of wavelength 449 nm. The vertical axis scale is set by ,85 = 83.2 rad. What are (a) the slit separation, (b) the total number of interference maxima (count them on both sides of the pattern's center), (c) the smallest angle for a maxima, and (d) the greatest angle for a minimum? Assume that none of the interference maxima are completely eliminated by a diffraction minimum. 3 (rad) With light from a gaseous discharge tube incident normally on a grating with slit separation 2.33 pm, sharp maxima for a certain wavelength of light are produced at angles 6 = -16.1 and +16.1. Compute the wavelength of the light