1. This week's study of physical optics involves: a) the understanding that interference occurs when two or more light waves that add together b) observing that a single slit or single wire apparatus can produce a diffraction pattern c) observing that a double-slit apparatus can produce an interference pattern d) all the answers are correct.

2. Monochromatic light rays striking a barrier with two slits produces an interference pattern on a distant screen, a) provided the distance to the screen is large compared to the separation of the two slits to allow for the small-angle approximation

b) such that dark fringes are produced when there is path length difference of integer wavelengths c) such that bright fringes are produced due to destructive interference d) none of the answers is correct.

3. For a single slit of width and producing a diffraction pattern, a) the dark bands (interference minima) are symmetric about the central axis b) an experimental value for a can be obtained from a plot of Xm as a function of m c) an experimental value for a can be obtained by averaging the values of a determined for each fringe d) all of the answers are correct.

4. When two waves with the same wavelength are 'out of phase' a) if they are a half-wavelength 'out of phase' then their crests and troughs add destructively

b) it is possible that their superposition may produce a net amplitude of zero c) their crests are not aligned d) all of the answers are correct.

5. Students performing this experiment: a) should take care not to direct the laser light into their own eyes b) will use small lasers to study the interference and diffraction of light c) should take care not to direct the laser light into the eyes of their classmates

d) all of the answers are correct.