Reading:

Cutnell and Johnson, Chapter 27.

Problems for Review:

Reviewing these problems gives you good exposure to this week's main topics, in practice. All are worked in the Student Study Guide [SSG] or Student Solutions Manual [SSM]; solutions are posted on our website http://www.physics.emory.edu/Classes/142-003.html , for those without these texts.

Conceptual:

MCAT review problem, [SSG] p 531.

Quantitative:

Chapter 27, problems 1, 5, 13, 17, 25, 33, 49, 61.

Problems to Hand In:

Conceptual:

Questions 1 through 4 refer to the interference pattern below:

The figure shows the interference pattern obtained in a double-slit experiment using light of wavelength 600 nm.

1. Which fringe is the same distance from both slits?
   1. A
   2. B
   3. C
   4. D
   5. E

2. Which fringe is 300 nm closer to one slit than the other?
   1. A
   2. B
   3. C
   4. D
   5. E

3. What angle (measured from the slits) separates fringe B from fringe E?
   1. $2^o$
   2. $12^o$
   3. $17^o$
   4. $24^o$
   5. $36^o$

4. Which of the following would be observed if the wavelength of light were decreased?
   1. The fringes would be brighter.
   2. The central bright fringe would change position.
   3. The distance between dark fringes would decrease.
   4. Single-slit diffraction effects would become nonnegligible.
   5. The angular separation between bright fringes would increase.

   
   

   Questions 5 through 9 refer to the situation below:

   
   

   An observer has two slides, A and B, of index of refraction $n_A= 1.5$ and $n_B = 1.7$. The top surface of slide A and bottom surface of slide B have been coated with a thin film to be nonreflective when light of wavelength 650 nm is incident in air.

5. If the coating material has $n=1.4$, what is the minimum thickness of the coating on the top surface of slide A?
   1. 0 nm
   2. 108 nm
   3. 116 nm
   4. 163 nm
   5. 325 nm

6. 
   
   $\parbox{2.0in}{ Slides A and B are held parallel, below the observer... ...the observer's eye, while staying parallel with B. What does the observer see?}$
   1. a pattern of dark and light fringes, with left and right edges bright, whose overall brightness varies in time
   2. a pattern of dark and light fringes, with left and right edges dark, whose overall brightness varies in time
   3. a uniformly bright rectangle, which is all dark
   4. a uniformly bright rectangle, which is all bright
   5. a uniformly bright rectangle, which darkens and brightens as slide A moves closer

   
   

   Questions 7 through 9 deal with the following wedge formed from slides A and B:

   
   

   $\parbox{2.0in}{ Slide A is placed atop slide B as shown to form a wedge, in contact at the left end and with separation 0.0325 mm at the right. }$

7. Assume the space between the slides is filled with air. Which of the patterns below does the observer see?
   1. a pattern of dark and light fringes, with left and right edges bright
   2. a pattern of dark and light fringes, with left and right edges dark
   3. a uniformly bright rectangle, which is all dark
   4. a uniformly bright rectangle, which is all bright
   5. a uniformly bright rectangle, which darkens and brightens in time

8. Assume the space between the slides is filled with sassafras oil, with index of refraction 1.6. Which of the patterns below does the observer see?
   1. a pattern of dark and light fringes, with left and right edges bright
   2. a pattern of dark and light fringes, with left and right edges dark
   3. a uniformly bright rectangle, which is all dark
   4. a uniformly bright rectangle, which is all bright
   5. a uniformly bright rectangle, which darkens and brightens in time

9. For the case above where the left and right edges of the wedge are bright, how many bright fringes lie in between them? (NOTES: for the pattern the answer would be 1; remember that $\lambda$ depends on the medium between the plates.)
   1. 0
   2. 50
   3. 99
   4. 100
   5. 159

Quantitative:

Chapter 27, problems 2, 6, 14, 28, 44, 56.