1.The coherence length of an ordinary white light source can be increased if we place a color filter in front
of the source so that the light that passes through the filter is somewhat monochromatic. The minimum
wavelength of the emerging light is 618 nm. What is the maximum wavelength in order for the
coherence length to be 0.09900 mm?

2. Two thin slits separated by 0.16 mm are illuminated by a monochromatic plane wave, producing
interference fringes on a distant screen. If the angle between adjacent fringes is 3.4 10
-3 rad, what is
the color of the fringes?
violet
blue
green
yellow
orange
red

3. Blue interference fringes are formed on a screen 1.9 m away from a double-slit illuminated by
monochromatic light of wavelength 476 nm. The distance between the centers of adjacent fringes is 4.5
mm. Find the separation between the two slits.

4. Two narrow slits separated by 0.37 mm are illuminated by monochromatic light of wavelength 529 nm.
How many bright fringes can be seen on a screen 1.2 cm wide placed 1.2 m in front of the slits?

5. How far is the second dark fringe to the right of the central bright fringe in the double-slit interference
pattern seen on a screen 2 m from the slits? The slits are separated by 0.4 mm and are illuminated by
monochromatic light of wavelength 624 nm.

6. A layer of oil, with a refractive index of 1.40798, 0.99506 mm thick, floats on water.
(a) Light of vacuum wavelength 632.800 nm, emitted by a stabilized He-Ne laser, is reflected at
normal incidence by the oil. How many wavelengths are contained in the light wave passing back
and forth through the oil?
(b) Does the light reflected from the two surfaces of the oil interfere constructively or
destructively?
constructive interference

destructive interference

7. Consider the following.
(a) Find the angle 𝜃 locating the first minimum in the Fraunhofer diffraction pattern of a single
slit of width 0.202 mm, using light of wavelength 417 nm.
(b) Find the angle locating the second minimum.

8. A Fraunhofer diffraction pattern of a single slit of width 0.331 mm is produced using light of wavelength
618 nm. Find the angle subtended by the central diffraction maximum.