1. Which of the following are electromagnetic waves?

(a) Sound

(b) Water waves

(c) Radar waves

(d) X rays

(e) All of the above

2. Explain the difference between interference and diffraction.

3. Explain the difference between constructive and destructive interference.

4. If waves did not exhibit the property of diffraction, under what conditions would your stereo system sound different?

5. Give an example of diffraction of water waves.

6. What happens to the frequency of a vibrating string on a guitar if the length of the string is decreased?