Question 1

Waves from two slits are in phase at the slits and travel to a distant screen to produce the third side maximum of the interference pattern. The difference in the distance traveled by the waves is:

Accepted Answer

A)   half a wavelength
B)   a wavelength
C)   three halves of a wavelength
D)   two wavelengths
E)   five halves of a wavelengthF) A) and B)
G) None of the above

Question 2

A glass (n = 1.6)  lens is coated with a thin film (n = 1.3)  to reduce reflection of certain incident light. If  λ\lambdaλ is the wavelength of the light in the film, the least film thickness is:

Accepted Answer

A)   less than  λ\lambdaλ /4
B)    λ\lambdaλ /4
C)    λ\lambdaλ /2
D)    λ\lambdaλ 
E)   more than  λ\lambdaλF) D) and E)
G) B) and D)

Question 3

In a Young's double-slit experiment, light of wavelength 500 nm illuminates two slits which are separated by 1 mm. The separation between adjacent bright fringes on a screen 5 m from the slits is:

Accepted Answer

A)   0.10 cm
B)   0.25 cm
C)   0.50 cm
D)   1.0 cm
E)   none of the aboveF) C) and E)
G) D) and E)

Question 4

A light wave with an electric field amplitude of E0 and a phase constant of zero is to be combined with one of the following waves. Which of these combinations produces the greatest intensity?

Accepted Answer

A)   wave A has an amplitude of E0 and a phase constant of zero
B)   wave B has an amplitude of E0 and a phase constant of   π\piπ 
C)   wave C has an amplitde of 2E0 and a phase constant of zero
D)   wave D has an amplitude of 2E0 and a phase constant of   π\piπ 
E)   wave E has an amplitude of 3E0 and a phase constant of  π\piπF) B) and E)
G) A) and B)

Question 5

The phase difference between the two waves which give rise to a dark spot in a Young's double-slit experiment is (where m = integer) :

Accepted Answer

A)   zero
B)   2  π\piπ m +   π\piπ /8
C)   2  π\piπ m +   π\piπ /4
D)   2  π\piπ m +   π\piπ /2
E)   2  π\piπ m +   π\piπF) B) and D)
G) D) and E)

Question 6

A monochromatic light source illuminates a double slit and the resulting interference pattern is observed on a distant screen. Let d = center-to-center slit spacing, a = individual slit width, D = screen-to-slit distance,  adjacent dark line spacing in the interference pattern. The wavelength of the light is then:

Accepted Answer

A)   
B)   Ld/a
C)   da/D
D)   
E)   F) A) and B)
G) C) and D)

Question 7

Monochromatic light, at normal incidence, strikes a thin film in air. If  λ\lambdaλ  denotes the wavelength in the film, what is the thinnest film in which the reflected light will be a maximum?

Accepted Answer

A)   much less than  λ\lambdaλ 
B)    λ\lambdaλ /4
C)    λ\lambdaλ /2
D)   3 λ\lambdaλ /4
E)    λ\lambdaλF) C) and D)
G) None of the above

Question 8

In a Young's double-slit experiment the center of a bright fringe occurs wherever waves from the slits differ in the distance they travel by a multiple of:

Accepted Answer

A)   a fourth of a wavelength
B)   a half a wavelength
C)   a wavelength
D)   three-fourths of a wavelength
E)   none of the aboveF) C) and E)
G) B) and C)

Question 9

Red light is viewed through a thin vertical soap film. At the third dark area shown, the thickness of the film, in terms of the wavelength within the film, is:

Accepted Answer

A)    λ\lambdaλ 
B)   3 λ\lambdaλ /4
C)    λ\lambdaλ /2
D)    λ\lambdaλ /4
E)   5 λ\lambdaλ /4 F) B) and D)
G) None of the above

Question 10

An air wedge is formed from two glass plates which are in contact at their left edges. There are ten dark bands when viewed by reflection using monochromatic light. The left edge of the top plate is now slowly lifted until the plates are parallel. During this process:

Accepted Answer

A)   the dark bands crowd toward the right edge
B)   the dark bands remain stationary
C)   the dark bands crowd toward the left edge
D)   the dark bands spread out, disappearing off the right edge
E)   the dark bands spread out, disappearing off the left edgeF) D) and E)
G) B) and C)

Question 11

Light from a point source X contains only blue and red components. After passing through a mysterious box, the light falls on a screen. Red and blue hands are observed as shown. The box must contain:

Accepted Answer

A)   a lens
B)   a mirror
C)   a prism
D)   a double slit
E)   a blue and red filterF) A) and E)
G) A) and B)

Question 12

In a thin film experiment, a wedge of air is used between two glass plates. If the wavelength of the incident light in air is 480 nm, how much thicker is the air wedge at the 16th dark fringe than it is at the 6th?

Accepted Answer

A)   2400 nm
B)   4800 nm
C)   240 nm
D)   480 nm
E)   none of theseF) A) and C)
G) C) and E)

Question 13

Units of "optical path length" are:

Accepted Answer

A)   m-1
B)   m
C)   m/s
D)   Hz/m
E)   m/HzF) All of the above
G) C) and E)

Question 14

Interference of light is evidence that:

Accepted Answer

A)   the speed of light is very large
B)   light is a transverse wave
C)   light is electromagnetic in character
D)   light is a wave phenomenon
E)   light does not obey conservation of energyF) A) and E)
G) B) and E)

Question 15

Waves from two slits are in phase at the slits and travel to a distant screen to produce the second minimum of the interference pattern. The difference in the distance traveled by the wave is:

Accepted Answer

A)   half a wavelength
B)   a wavelength
C)   three halves of a wavelength
D)   two wavelengths
E)   three wavelengthsF) None of the above
G) All of the above

Question 16

Three experiments involving a thin film (in air)  are shown. If t denotes the film thickness and  λ\lambdaλ  denotes the wavelength of the light in the film, which experiments will produce constructive interference as seen by the observer?

Accepted Answer

A)   I only
B)   II only
C)   III only
D)   I and III only
E)   II and III only F) A) and B)
G) D) and E)

Question 17

A lens with a refractive index of 1.5 is coated with a material of refractive index 1.2 in order to minimize reflection. If  λ\lambdaλ denotes the wavelength of the incident light in air, what is the thinnest possible such coating?

Accepted Answer

A)   0.5 λ\lambdaλ 
B)   0.416 λ\lambdaλ 
C)   0.3 λ\lambdaλ 
D)   0.208 λ\lambdaλ 
E)   0.25 λ\lambdaλF) All of the above
G) B) and E)

Question 18

The reason there are two slits, rather than one, in a Young's experiment is:

Accepted Answer

A)   to increase the intensity
B)   one slit is for frequency, the other for wavelength
C)   to create a path length difference
D)   one slit is for  fields, the other is for  fields
E)   two slits in parallel offer less resistanceF) A) and C)
G) None of the above

Question 19

A "wave front" is a surface of constant:

Accepted Answer

A)   phase
B)   frequency
C)   wavelength
D)   amplitude
E)   speedF) A) and C)
G) A) and B)

Question 20

In a Young's double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to:

Accepted Answer

A)   D/2
B)   
C)   
D)   2D
E)   4DF) B) and E)
G) A) and C)

Exam 35: Interference

Interference of light is evidence that:

Correct Answer
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Correct Answer
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In a Young's double-slit experiment, light of wavelength 500 nm illuminates two slits which are separated by 1 mm. The separation between adjacent bright fringes on a screen 5 m from the slits is:

Correct Answer
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Waves from two slits are in phase at the slits and travel to a distant screen to produce the third side maximum of the interference pattern. The difference in the distance traveled by the waves is:

Correct Answer
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Waves from two slits are in phase at the slits and travel to a distant screen to produce the second minimum of the interference pattern. The difference in the distance traveled by the wave is:

Correct Answer
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Correct Answer
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Correct Answer
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In a thin film experiment, a wedge of air is used between two glass plates. If the wavelength of the incident light in air is 480 nm, how much thicker is the air wedge at the 16th dark fringe than it is at the 6th?

Correct Answer
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The phase difference between the two waves which give rise to a dark spot in a Young's double-slit experiment is (where m = integer) :

Correct Answer
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Light from a point source X contains only blue and red components. After passing through a mysterious box, the light falls on a screen. Red and blue hands are observed as shown. The box must contain:

Correct Answer
verified

In a Young's double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to:

Correct Answer
verified

Correct Answer
verified

A glass (n = 1.6) lens is coated with a thin film (n = 1.3) to reduce reflection of certain incident light. If $\lambda$ is the wavelength of the light in the film, the least film thickness is:

Correct Answer
verified

An air wedge is formed from two glass plates which are in contact at their left edges. There are ten dark bands when viewed by reflection using monochromatic light. The left edge of the top plate is now slowly lifted until the plates are parallel. During this process:

Correct Answer
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A light wave with an electric field amplitude of E₀ and a phase constant of zero is to be combined with one of the following waves. Which of these combinations produces the greatest intensity?

Correct Answer
verified

A "wave front" is a surface of constant:

Correct Answer
verified

In a Young's double-slit experiment the center of a bright fringe occurs wherever waves from the slits differ in the distance they travel by a multiple of:

Correct Answer
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Units of "optical path length" are:

Correct Answer
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Monochromatic light, at normal incidence, strikes a thin film in air. If $\lambda$ denotes the wavelength in the film, what is the thinnest film in which the reflected light will be a maximum?

Correct Answer
verified

The reason there are two slits, rather than one, in a Young's experiment is:

Correct Answer
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Exam 35: Interference

Interference of light is evidence that:

Correct AnswerverifiedShow Answer

A lens with a refractive index of 1.5 is coated with a material of refractive index 1.2 in order to minimize reflection. If λ\lambdaλ denotes the wavelength of the incident light in air, what is the thinnest possible such coating?

Correct AnswerverifiedShow Answer

In a Young's double-slit experiment, light of wavelength 500 nm illuminates two slits which are separated by 1 mm. The separation between adjacent bright fringes on a screen 5 m from the slits is:

Correct AnswerverifiedShow Answer

Waves from two slits are in phase at the slits and travel to a distant screen to produce the third side maximum of the interference pattern. The difference in the distance traveled by the waves is:

Correct AnswerverifiedShow Answer

Waves from two slits are in phase at the slits and travel to a distant screen to produce the second minimum of the interference pattern. The difference in the distance traveled by the wave is:

Correct AnswerverifiedShow Answer

Three experiments involving a thin film (in air) are shown. If t denotes the film thickness and λ\lambdaλ denotes the wavelength of the light in the film, which experiments will produce constructive interference as seen by the observer?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In a thin film experiment, a wedge of air is used between two glass plates. If the wavelength of the incident light in air is 480 nm, how much thicker is the air wedge at the 16th dark fringe than it is at the 6th?

Correct AnswerverifiedShow Answer

The phase difference between the two waves which give rise to a dark spot in a Young's double-slit experiment is (where m = integer) :

Correct AnswerverifiedShow Answer

Light from a point source X contains only blue and red components. After passing through a mysterious box, the light falls on a screen. Red and blue hands are observed as shown. The box must contain:

Correct AnswerverifiedShow Answer

In a Young's double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to:

Correct AnswerverifiedShow Answer

Red light is viewed through a thin vertical soap film. At the third dark area shown, the thickness of the film, in terms of the wavelength within the film, is:

Correct AnswerverifiedShow Answer

A glass (n = 1.6) lens is coated with a thin film (n = 1.3) to reduce reflection of certain incident light. If λ\lambdaλ is the wavelength of the light in the film, the least film thickness is:

Correct AnswerverifiedShow Answer

An air wedge is formed from two glass plates which are in contact at their left edges. There are ten dark bands when viewed by reflection using monochromatic light. The left edge of the top plate is now slowly lifted until the plates are parallel. During this process:

Correct AnswerverifiedShow Answer

A light wave with an electric field amplitude of E0 and a phase constant of zero is to be combined with one of the following waves. Which of these combinations produces the greatest intensity?

Correct AnswerverifiedShow Answer

A "wave front" is a surface of constant:

Correct AnswerverifiedShow Answer

In a Young's double-slit experiment the center of a bright fringe occurs wherever waves from the slits differ in the distance they travel by a multiple of:

Correct AnswerverifiedShow Answer

Units of "optical path length" are:

Correct AnswerverifiedShow Answer

Monochromatic light, at normal incidence, strikes a thin film in air. If λ\lambdaλ denotes the wavelength in the film, what is the thinnest film in which the reflected light will be a maximum?

Correct AnswerverifiedShow Answer

The reason there are two slits, rather than one, in a Young's experiment is:

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A glass (n = 1.6) lens is coated with a thin film (n = 1.3) to reduce reflection of certain incident light. If $\lambda$ is the wavelength of the light in the film, the least film thickness is:

Correct Answer
verified

Correct Answer
verified

A light wave with an electric field amplitude of E₀ and a phase constant of zero is to be combined with one of the following waves. Which of these combinations produces the greatest intensity?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Monochromatic light, at normal incidence, strikes a thin film in air. If $\lambda$ denotes the wavelength in the film, what is the thinnest film in which the reflected light will be a maximum?

Correct Answer
verified

Correct Answer
verified