1. What condition is needed for Fraunhofer diffraction? a. The slit must be narrow enough that a substantial amount of diffraction can occur, but not so narrow that it acts as a single point source of waves. b. The light source must be monochromatic. c. The light source must be far enough from the slit that the rays reaching the slit are approximately parallel. d. All of the above.

10. Light of wavelength 520 nm passes through a grating with 4000 lines/cm and falls on a screen located 1.6 m from the grating. (a) Draw a picture (not to scale) that schematically represents the process and label all known distances and angles. (b) Determine the angular deflection of the second bright band. (c) Determine the separation of the 2nd order bright spot from the central maximum. (d) Determine the total number of constructively interfering beams that are formed after the light passes the grating.

10. You have a single-slit diffraction apparatus, with a slit 4.60 × 10−6 m wide arranged 1.80 m from the screen. You would like an anti-node to appear 68.2 cm from the right bisector. What are two possible visible wavelengths you could use?

18. Suppose that you are shining light through a small slit (width = 400 nm). Which will diffract more: a red laser with a wavelength of 650 nm or a green laser with a wavelength of 450 nm?     not enough information to determine     the diffraction will be the same     green laser     red laser