1. What types of waves exhibit pronounced diffraction and interference effects when encountering obstacles that have a size similar to the wavelength of the wave? A. Electromagnetic waves B. Sound waves C. Waves of matter (i.e. de Broglie waves) D. All of the above E. None of the above Solution: D. All waves show diffraction and interference effects. For some examples, see Lecture 17 slides 6 and 13 and Lecture 22 slide 9