Deck 28: Physical Optics: Interference and Diffraction

Question 1

A wave that travels from a medium of lower index of refraction to a medium of higher index of refraction undergoes 180° phase changes relative to the incident wave.

Answer 1

True

Question 2

In Young's double-slit experiment, light coming from each slit arrives in phase at the first maximum on either side of the central bright fringe.

Answer 2

True

Question 3

The particle theory of light, as well as the wave theory of light, are both supported by the interference of light.

Answer 3

True

Question 4

When light travels from a larger index of refraction towards a smaller index of refraction, there is no phase change upon reflection at the boundary.

Question 5

In the two-slit experiment, for the condition of bright fringes, the value of m = +2 corresponds to a path difference of λ.

Question 6

If the first maximum of one circular diffraction pattern passes through the center of a second diffraction pattern, the two sources responsible for the pattern will appear to be a single source.

Question 7

The law of reflection, as well as the law of refraction, can be derived using Huygens' principle.

Question 8

In the experiment for interference using the concept of air wedge, the point where the glass plates touch in an air wedge is a dark fringe.

Question 9

The interference pattern observed in Newton's rings experiment is because of the path difference between the top surface and the bottom surface of the air between the pieces of glass.

Question 10

If two or more sources of light are to show interference patterns, they must be coherent.

Question 11

Coherent sources of light have a varying phase difference.

Question 12

In the two-slit experiment, for the condition of dark fringes, the value of m = +1 corresponds to a path difference of 3λ/2.

Question 13

Interference is the superposition of two or more waves.

Question 14

In a single-slit diffraction experiment, the central maximum is broadened if the wavelength of light increased.

Question 15

In the two-slit experiment, for the condition of dark fringes, the value of m = +2 corresponds to a path difference of 3λ/2.

Question 16

For two beams of light traveling different distances in reaching a point, and to form maximum constructive interference at that point, the beams must travel paths that differ by a whole number of wavelengths.

Question 17

Two coherent light sources are characterized by

A) having the same amplitude.
B) having the same frequency.
C) having the same wavelength.
D) having the same velocity.
E) having the same frequency and maintaining a constant phase difference.

Question 18

Which one of the following properties of light is evidence of the wave nature of light?

A) Reflection of light
B) Refraction of light
C) Emission of light
D) Dispersion of light
E) Interference of light

Question 19

The wavelength of light is important for thin film interference to occur within the film itself.

Question 20

The interference of light is because of its particle nature as suggested by Sir Isaac Newton.

Question 21

In a single-slit diffraction experiment, the width of the slit through which light passes is reduced. What happens to the central bright fringe?

A) It stays the same.
B) It becomes narrower.
C) It becomes wider.
D) We must know the wavelength of the light to answer.

Question 22

When a beam of light, which is traveling in air, is reflected by a glass surface, there is

A) a 90° phase change in the reflected beam.
B) no phase change in the reflected beam.
C) a 180° phase change in the reflected beam.
D) a 60° phase change in the reflected beam.
E) a 45° phase change in the reflected beam.

Question 23

Consider two diffraction gratings; one has 4000 lines per cm and the other one has 6000 lines per cm. Make a statement comparing the dispersion of the two gratings.

A) The 4000-line grating produces the greater dispersion.
B) The 6000-line grating produces the greater dispersion.
C) Both gratings produce the same dispersion, but the orders are sharper for the 4000-line grating.
D) Both gratings produce the same dispersion, but the orders are sharper for the 6000-line grating.

Question 24

In the two-slit experiment, for the condition of dark fringes, the value of m = +4 corresponds to a path difference of

A) (1/2)λ
B) (3/2)λ
C) (5/2)λ
D) (7/2)λ
E) (9/2)λ

Question 25

A single-slit diffraction pattern is formed on a distant screen. Assuming the angles involved are small, by what factor will the width of the central bright spot on the screen change if the slit width is doubled?

A) It will be cut to one-quarter its original size.
B) It will be cut in half.
C) It will double.
D) It will become four times as large.
E) It will become eight times as large.

Question 26

If the distance between the slits in Young's two-slit experiment is decreased, which one of the following statements is true of the interference pattern?

A) The distance between the maxima stays the same.
B) The distance between the maxima decreases.
C) The distance between the minima stays the same.
D) The distance between the minima increases.
E) Impossible to tell without knowing the wavelength of light in use.

Question 27

If the wavelength of light in Young's two-slit experiment is decreased, which one of the following statements is true of the interference pattern?

A) The distance between the minima stays the same.
B) The distance between the maxima decreases.
C) The distance between maxima stays the same.
D) The distance between the maxima increases.
E) Impossible to tell without knowing the separation between the slits.

Question 28

Which one of the following experiments is the justification for the wave theory of light?

A) Frank-Hertz experiment
B) Newton's rings experiment
C) Huygens' experiment
D) Young's double slit experiment
E) none of the above

Question 29

In a double-slit interference experiment you are asked to use laser light of different wavelengths and determine the separation between adjacent maxima. You observe that this separation is greatest when you illuminate the double slit with

A) blue light.
B) green light.
C) yellow light.
D) red light.
E) The separation is the same for all wavelengths.

Question 30

Two beams of coherent light travel different paths arriving at point P. If the maximum constructive interference is to occur at point P, what should be the phase difference between the two waves?

A) The phase difference between the two waves is π/4.
B) The phase difference between the two waves is π/2.
C) The phase difference between the two waves is π.
D) The phase difference between the two waves is 2π.
E) The phase difference between the two waves is 5π/2.

Question 31

A single-slit diffraction pattern is formed on a distant screen. Assuming the angles involved are small, by what factor will the width of the central bright spot on the screen change if the distance from the slit to the screen is doubled?

A) It will be cut to one-quarter its original size.
B) It will be cut in half.
C) It will double.
D) It will become four times as large.
E) It will become eight times as large.

Question 32

Which one of the following mathematical expressions is correct for destructive interference for two beams of light in the double slit experiment?

A) Path Difference = (m - 1/2) λ, m = 0, ±1, ±2, . . .
B) Path Difference = λ/m, m = 0, ±1, ±2, . . .
C) Path Difference = mλ, m = 0, ±1, ±2, . . .
D) Path Difference = mλ², m = 0, ±1, ±2, . . .
E) Path Difference = m/λ, m = 0, ±1, ±2, . . .

Question 33

A double-slit interference experiment is performed in the air. Later, the same apparatus is immersed in benzene (index of refraction, n = 1.50), and the experiment is repeated. When the apparatus is in benzene, you observe the interference fringes to be

A) more closely spaced as when the apparatus is in air.
B) equally spaced as when the apparatus is in air.
C) more widely spaced as when the apparatus is in air.
D) Impossible to tell without knowing the wavelength of light in use.
E) Impossible to tell without knowing the separation between the slits.

Question 34

In the two-slit experiment, for the condition of bright fringes, the value of m = +4 corresponds to a path difference of

A) 4λ
B) 3λ
C) 2λ
D) λ
E) (1/2)λ

Question 35

Which one of the following mathematical expressions is correct for constructive interference for two beams of light in the double slit experiment?

A) Path Difference = (m - 1/2) λ, m = 0, ±1, ±2, . . .
B) Path Difference = λ/m, m = 0, ±1, ±2, . . .
C) Path Difference = mλ, m = 0, ±1, ±2, . . .
D) Path Difference = m , m = 0, ±1, ±2, . . .
E) Path Difference = m/λ, m = 0, ±1, ±2,. . . .

Question 36

When a beam of light, which is traveling in glass, strikes an air boundary, there is

A) a 90° phase change in the reflected beam.
B) no phase change in the reflected beam.
C) a 180° phase change in the reflected beam.
D) a 60° phase change in the reflected beam.
E) a 45° phase change in the reflected beam.

Question 37

If the distance between the slits and the screen is increased in Young's two-slit experiment, which one of the following statements is true of the interference pattern?

A) The distance between the minima stays the same.
B) The distance between the minima decreases.
C) The distance between the maxima stays the same
D) The distance between the maxima increases.
E) Impossible to tell without knowing the wavelength of light in use.

Question 38

In Young's two-slit experiment, a beam of light from a slit reaches at a point on the screen one wavelength behind the wave from the other slit. What is observed on the screen at that point?

A) Dark fringe
B) An empty space
C) Bright-dark fringe
D) Dark-bright fringe
E) Bright fringe

Question 39

Two beams of coherent light travel different paths arriving at point P. If the maximum destructive interference is to occur at point P, what should be the phase difference between the two waves?

A) The phase difference between the two waves is π/4.
B) The phase difference between the two waves is π/2.
C) The phase difference between the two waves is π.
D) The phase difference between the two waves is 2π.
E) The two waves are in phase.

Question 40

A single-slit diffraction pattern is formed on a distant screen. Assuming the angles involved are small, by what factor will the width of the central bright spot on the screen change if the wavelength is doubled?

A) It will be cut to one-quarter its original size.
B) It will be cut in half.
C) It will double.
D) It will become four times as large.
E) It will become eight times as large.

Question 41

A single-slit experiment uses light of wavelength 720. nm with a slit separation of 0.250 mm and a screen placed 2.7 m away.
(a) What is the angular width of the central fringe?
(b) What is the linear width of the central fringe on the screen?
(c) What is the linear distance on the screen between the central maximum and the 1st order maximum?

Question 42

In a diffraction experiment, light of 600. nm wavelength produces a first-order maximum 0.350 mm from the central maximum on a distant screen. A second monochromatic source produces a third-order maximum 0.870 mm from the central maximum when it passes through the same diffraction grating. What is the wavelength of the light from the second source?

Question 43

In Young's two-slit experiment, the distance between the slits and the screen is 1.10 m and the distance between the slits is 0.0400 mm. If the second order bright fringe is measured to be 4.20 cm from the centerline, what is the wavelength of light?

A) 200 nm
B) 381 nm
C) 401 nm
D) 620 nm
E) 763 nm

Question 44

A single slit, which is 0.0500 mm wide, is illuminated by light of 550. nm wavelength. What is the angular separation between the first two minima on either side of the central maximum?

Question 45

Consider two diffraction gratings with the same slit separation, the only difference being that one grating has 3 slits and the other 4 slits. If both gratings are illuminated with a beam of the same monochromatic light, make a statement concerning the separation between the orders.

A) The grating with 3 slits produces the greater separation between orders.
B) The grating with 4 slits produces the greater separation between orders.
C) Both gratings produce the same separation between orders.
D) Both gratings produce the same separation between orders, but the orders are better defined with the 4-slit grating.

Question 46

In the two-slit experiment, the distance between the slits and the screen is 1.10 m and the distance between the slits is 0.100 mm. If the first-order bright fringe is measured to be 3.40 cm from the centerline, what is the wavelength of light?

A) 354 nm
B) 241 nm
C) 133 nm
D) 3.10 μm
E) 2.11 μm

Question 47

In the two-slit experiment, monochromatic light of wavelength 600 nm passes through a pair of slits separated by 2.20 × 10^-5 m. What is the angle corresponding to the second dark fringe?

A) 4.70°
B) 3.51°
C) 3.94°
D) 1.17°
E) 2.35°

Question 48

A diffraction grating has 6000. lines per centimeter ruled on it. What is the angular separation between the second and the third orders on the same side of the central order when the grating is illuminated with a beam of light of wavelength 550. nm?

Question 49

A soap bubble has an index of refraction of 1.33. What minimum thickness of this bubble will ensure maximum reflectance of normally incident 530. nm wavelength light?

Question 50

In a double-slit experiment, the slit separation is 2.0 mm, and two wavelengths, 750. nm and 900. nm, illuminate the slits. A screen is placed 2.0 m from the slits. At what distance from the central maximum on the screen will a bright fringe from one pattern first coincide with a bright fringe from the other?

Question 51

Light of wavelength 0.50 μm illuminates a soap film (n = 1.33). What is the minimum thickness of film that will give an interference when the light is incident normally on it?

Question 52

When red light illuminates a grating with 7000. lines per centimeter, its second maximum is at 62.4°. What is the wavelength of the light?

Question 53

Consider a diffraction grating with 7000. lines/cm with a screen 2.50 m away and 440. nm wavelength light.
(a) How many side maxima would be observed on one side of the central maximum?
(b) What is the linear distance between the 1st and 2nd maxima?

Question 54

In the two-slit experiment, the distance between the slits and the screen is 1.1 m and the distance between the slits is 0.040 mm. If the first-order bright fringe is measured to be 3.4 cm from the centerline, what is the distance between the adjacent bright fringes?

A) 1.7 cm
B) 5.1 cm
C) 7.0 cm
D) 6.8 cm
E) 3.4 cm

Question 55

In a two-slit experiment a third order bright fringe is observed at an angle of 7.10°. If the wavelength of light is 595 nm, what is the slit separation?

A) 1.44 × 10^-5 m
B) 1.07 × 10^-5 m
C) 2.12 × 10^-5 m
D) 2.53 × 10^-5 m
E) 3.76 × 10^-5 m

Question 56

Light of wavelength λ = 540 nm passes through a pair of slits with separation 3.4 × 10^-5 m. What is the angle corresponding to the second bright fringe?

A) 1.8°
B) 3.7°
C) 4.3°
D) 1.5°
E) 5.0°

Question 57

In the two-slit experiment, monochromatic light of wavelength 600 nm passes through a pair of slits separated by 2.20 × 10^-5 m. What is the angle corresponding to the first bright fringe?

A) 1.56°
B) 2.22°
C) 3.12°
D) 4.70°
E) 6.24°

Question 58

A double-slit experiment uses light of wavelength 633. nm with a slit separation of 0.100 mm and a screen placed 2.0 m away.
(a) What is the linear width of the central fringe?
(b) What is the lateral distance between 1st and 2nd order fringes?
(c) What is the angular separation between the central maximum and the 1st order maximum?

Question 59

In Young's two-slit experiment, the distance between the slits and the screen is 1.1 m and the distance between the slits is 0.040 mm. If the second order bright fringe is measured to be 4.2 cm from the centerline, what is the distance between the adjacent fringes?

A) 6.3 cm
B) 3.1 cm
C) 1.3 cm
D) 2.1 cm
E) 4.2 cm

Question 60

In a two-slit experiment, the slit separation is 3.00 × 10^-5 m. The interference pattern is created on a screen that is 2.00 m away from the slits. If the 7th bright fringe on the screen is a linear distance of 10.0 cm away from the central fringe, what is the wavelength of the light?

A) 100 nm
B) 204 nm
C) 214 nm
D) 224 nm
E) 234 nm

Question 61

If the wavelength of light in vacuum is 469 nm, what is the wavelength of light in a thin film of index of refraction 1.42?

A) 110 nm
B) 220 nm
C) 330 nm
D) 440 nm
E) 550 nm

Question 62

A piece of glass has a thin film of gasoline floating on it. A beam of light is shining perpendicular on the film. If the wavelength of light incident on the film is 560 nm and the indices of refraction of gasoline and glass are 1.40 and 1.50, respectively, what is the minimum thickness of the film to see a bright reflection?

A) 500 nm
B) 400 nm
C) 300 nm
D) 200 nm
E) 100 nm

Question 63

The distance between the slits in the two-slit experiment is 1.50 × 10^-5 m. A beam of light of wavelength 600 nm is used and the distance between the slit and the screen is 2.00 m. What is the distance on the screen between the central bright fringe and the 4th order bright fringe?

A) 0.132 m
B) 0.201 m
C) 0.324 m
D) 0.528 m
E) 0.688 m

Question 64

450 nm of light falls on a single slit of width 0.30 mm. What is the angular width of the central diffraction peak?

A) 0.086°
B) 0.13°
C) 0.17°
D) 0.26°
E) 0.35°

Question 65

In a single-slit diffraction experiment, the width of the slit is 1.90 μm. If a beam of light of wavelength 610 nm forms a diffraction pattern, what is the angle associated with the second dark fringe above the central bright fringe?

A) 11.4°
B) 9.35°
C) 12.2°
D) 39.9°
E) 18.7°

Question 66

A very fine thread is placed between two glass plates on one side and the other side is touching to form a wedge. A beam of monochromatic light of wavelength 600 nm illuminates the wedge and 178 bright fringes are observed. What is the thickness of the thread?

A) 22.3 μm
B) 26.7 μm
C) 32.3 μm
D) 53.3 μm
E) 76.3 μm

Question 67

In a single slit diffraction experiment, the width of the slit is 3.1 × 10^-5 m and the distance from the slit to the screen is 2.2 m. If the beam of light of wavelength 600 nm passes through the slit and forms a diffraction pattern on the screen, what is the linear distance on the screen from the center of the diffraction pattern to the first dark fringe?

A) 2.1 cm
B) 4.3 cm
C) 6.3 cm
D) 7.4 cm
E) 8.5 cm

Question 68

The wavelength of light in a thin film is 360 nm and the wavelength of light in vacuum is 469 nm. What is the index of refraction for the film?

A) 1.10
B) 1.30
C) 1.50
D) 1.70
E) 1.90

Question 69

A soap bubble has an index of refraction of 1.33. What minimum thickness of this bubble will ensure maximum reflectance of normally incident 530 nm wavelength light?

A) 24.9 nm
B) 76.9 nm
C) 99.6 nm
D) 199 nm
E) 398 nm

Question 70

A puddle of water has a thin film of gasoline floating on it. A beam of light is shining perpendicular on the film. If the wavelength of light incident on the film is 560 nm and the indices of refraction of gasoline and water are 1.40 and 1.33, respectively, what is the minimum thickness of the film to see a bright reflection?

A) 100 nm
B) 200 nm
C) 300 nm
D) 400 nm
E) 500 nm

Question 71

In a single-slit diffraction experiment, the width of the slit is 1.90 μm. If a beam of light of wavelength 610 nm forms a diffraction pattern, what is the angle associated with the first minimum above the central bright fringe?

A) 9.35°
B) 11.4°
C) 12.2°
D) 39.9°
E) 18.7°

Question 72

Light of wavelength 500 nm illuminates a soap film ( n = 1.33). What is the minimum thickness of film that will give an interference when the light is incident normally on it?

A) 24 nm
B) 56 nm
C) 94 nm
D) 188 nm
E) 376 nm

Question 73

A 500 nm wavelength light illuminates a soap film with an index of refraction 1.33 to make it look bright. If the beam of light is incident normal on the film, what is the minimum thickness of the film?

A) 47.0 nm
B) 74.0 nm
C) 94.0 nm
D) 152 nm
E) 268 nm

Question 74

What is the thickness of a soap bubble film (n = 1.38) that results in a constructive interference in the reflected light if this film is illuminated by a beam of light of wavelength 610 nm?

A) 222 nm
B) 111 nm
C) 333 nm
D) 444 nm
E) 555 nm

Question 75

A sodium light (λ = 589.3 nm) is used to view a soap film to make it look black when directed perpendicular to the film. What is the minimum thickness of the soap film if the index of refraction of soap solution is 1.38?

A) 114 nm
B) 194 nm
C) 294 nm
D) 314 nm
E) 214 nm

Question 76

In a single-slit diffraction experiment, a beam of monochromatic light passes through a slit of width 11.0 μm. If the first order dark fringe of the resulting diffraction pattern is at an angle of 4.31°, what is the wavelength of light?

A) 827 nm
B) 301 nm
C) 602 nm
D) 402 nm
E) 201 nm

Question 77

In a single slit diffraction experiment, the width of the slit is 3.1 × 10^-5 m and the distance from the slit to the screen is 2.2 m. If the beam of light of wavelength 600 nm passes through the slit and forms a diffraction pattern on the screen, what is the linear distance on the screen from the center of the diffraction pattern to the second dark fringe?

A) 3.9 cm
B) 4.2 cm
C) 6.3 cm
D) 2.1 cm
E) 8.5 cm

Question 78

A 500 nm light is reflected constructively from a thin layer of oil of index of refraction 1.25, which rests on the top of water of index of refraction 1.33. What is the minimum thickness of the layer of oil?

A) 100 nm
B) 150 nm
C) 175 nm
D) 200 nm
E) 225 nm

Question 79

A film of thickness 106 nm soap bubble film (n = 1.42) results in a constructive interference in the reflected light if this film is illuminated by a beam of light with a wavelength of 601 nm. What are the next three thicknesses of this film that will also result in a constructive interference?

A) 212 nm, 318 nm, 424 nm
B) 53.0 nm, 35.3 nm, 26.5 nm
C) 212 nm, 424 nm, 636 nm
D) 67.0 nm, 42.4 nm, 22.3 nm
E) 317 nm, 529 nm, 741 nm

Question 80

What is the minimum thickness of a nonreflecting film coating (n = 1.30) on a glass lens (n = 1.50) for wavelength 500 nm?

A) 250 nm
B) 221 nm
C) 192 nm
D) 167 nm
E) 96.2 nm