# Problems : Diffraction-Double slit, single slit, and diffraction grating interference

1. You are conducting a single-slit diffraction experiment with light of wavelength λ . What appears, on a distant viewing screen, at a point at which the top and bottom rays through the slit have a path length difference equal to (a) 5 λ and (b) 4.5 λ?
2. Light of frequency f illuminating a long narrow slit produces a diffraction pattern. (a) If we switch to light of frequency 1.3f, does the pattern expand away from the center or contract toward the center? (b) Does the pattern expand or contract if, instead, we submerge the equipment in clear corn syrup?
3. The distance between the first and fifth minima of a single-slit diffraction pattern is 0.35 mm with the screen 40 cm away from the slit, when light of wavelength 550 nm is used. (a) Find the slit width. (b) Calculate the angle θ of the first diffraction minimum.
4. What must be the ratio of the slit width to the wavelength for a single slit to have the first diffraction minimum at θ=45.0°?
5. Monochromatic light of wavelength 441 nm is incident on a narrow slit. On a screen 2.00 m away, the distance between the second diffraction minimum and the central maximum is 1.50 cm. (a) Calculate the angle of diffraction θ of the second minimum. (b) Find the width of the slit.