Conceptual Questions:
1. Interference effects observed in the early 1800's were instrumental in supporting a concept of the existence of which property of light?
a. polarization
b. particle nature
c. wave nature
d. electro-magnetic character
2. The blue tint of a coated camera lens is largely caused by what effects?
a. diffraction
b. refraction
c. polarization
d. interference
3. When light passes from a material with a high index of refraction into material with a low index of refraction:
a. none of the light is reflected.
b. some light is reflected without a change of phase.
c. some light is reflected with a 180° change of phase.
d. the light that is not reflected has a 108 ° change of phase.
Numerical Problems: answers link to a help page.
1. A Young's double slit has a slit separation of 2.5 x10-5 m on which a monochromatic light beam is directed. The resultant bright fringes on a screen 1.0 m from the double slit are separated by 2.3 x10-2 m. What is the wavelength of this beam? (1 nm = l0-9 m)
2. What is the minimum thickness of a soap bubble film (n = 1.46) on which light of wave length 500 nm shines, assuming one observes constructive interference of the reflected light?
3. A silicon monoxide thin film (n = 1.45) of thickness 97.4 nm is applied to a camera lens made of glass (n = 1.58). This will result in a destructive interference for reflected light of what wavelength?
4. In a Young's double slit interference apparatus, by what factor is the distance between adjacent light and dark fringes changed when the separation between slits is tripled?
5. In a Young's double slit interference apparatus, by what factor is the distance between adjacent light and dark fringes changed when the wavelength of the source is tripled?
6. Two flat glass plates are in contact along one end and are separated by a sheet of tissue paper at the other end. A monochromatic source of 490 nm illuminates the top plate. If 21 dark bands are counted across the top plate, what is the paper thickness?
7. A puddle of water (n = 1.33) is covered with a very thin layer of oil (n = 1.20). How thick is the oil in the region that reflects light with a wavelength of 550 nm?