Question 1

The first angular minima location for a single-slit diffraction having slit width of $1 \mu \mathrm { m }$ and wavelength of 500 nm is

Accepted Answer

A)  10º. 
B)  45º. 
C)  20º. 
D)  30º. 
A)  10º. 
B)  45º. 
C)  20º. 
D)  30º.

Question 2

All of the following considerations are important in explaining the observed interference patterns produced by light reflection from a thin film except

Accepted Answer

A)  the superposition of incident light with reflected light. 
B)  the superposition of reflections coming from separate points on the reflecting surface. 
C)  the time average of the intensity of the light at places that are not nodes. 
D)  the relative magnitudes of the E-fields contributing to the resultant nodal points. 
A)  the superposition of incident light with reflected light. 
B)  the superposition of reflections coming from separate points on the reflecting surface. 
C)  the time average of the intensity of the light at places that are not nodes. 
D)  the relative magnitudes of the E-fields contributing to the resultant nodal points.

Question 3

Red light having a wavelength of 690 nm (in air) is vertically incident on a thin film of oil that has an index of refraction of 1.19. The film of oil floats above water (having an index of refraction of 1.30). No red light is reflected. The minimum (nonzero) thickness of the film of oil is

Accepted Answer

A)  290 nm. 
B)  345 nm. 
C)  580 nm. 
D)  145 nm. 
A)  290 nm. 
B)  345 nm. 
C)  580 nm. 
D)  145 nm.

Question 4

An electric field phasor makes an angle of $\omega t$ relative to the x axis. The instantaneous value of the electric field is given by the

Accepted Answer

A)  projection of the phasor along the y axis. 
B)  magnitude of the phasor. 
C)  projection of the phasor along the x axis. 
D)  direction of the phasor. 
A)  projection of the phasor along the y axis. 
B)  magnitude of the phasor. 
C)  projection of the phasor along the x axis. 
D)  direction of the phasor.

Question 5

Find the critical angle for two objects 1 meter apart when viewed using 500-nm light (assume a rectangular aperture):

Accepted Answer

A)  $5 \times 10 ^ { - 7 }$ radians 
B)  $6 \times 10 ^ { - 5 }$ radians 
C)  $9 \times 10 ^ { - 6 }$ radians 
D)  $7 \times 10 ^ { - 6 }$ radians 
A)  $5 \times 10 ^ { - 7 }$ radians 
B)  $6 \times 10 ^ { - 5 }$ radians 
C)  $9 \times 10 ^ { - 6 }$ radians 
D)  $7 \times 10 ^ { - 6 }$ radians

Question 6

In a Young's double-slit experiment, the time-averaged value of $\cos ^ { 2 } \left( \omega t - 2 \pi r _ { 0 } / \lambda \right)$, where $r _ { 0 }$ is the distance from the center of the slits to the point of interest, and $\lambda$ is the wavelength of light, is

Accepted Answer

A)  0 
B)  1/2. 
C)  $r _ { 0 } / \lambda .$ 
D)  $1 / \sqrt { 2 }$ 
A)  0 
B)  1/2. 
C)  $r _ { 0 } / \lambda .$ 
D)  $1 / \sqrt { 2 }$

Question 7

The minimum film thickness for which a reflection maximum occurs is the same in all of the following situations except

Accepted Answer

A)  when the film is surrounded by a material of larger index of refraction. 
B)  when the film is surrounded by a material of smaller index of refraction. 
C)  when the film is bordered by a material of larger index of refraction on one side and a material of smaller index of refraction on the other side. 
D)  Hold it! There are no exceptions. 
A)  when the film is surrounded by a material of larger index of refraction. 
B)  when the film is surrounded by a material of smaller index of refraction. 
C)  when the film is bordered by a material of larger index of refraction on one side and a material of smaller index of refraction on the other side. 
D)  Hold it! There are no exceptions.

Question 8

In a Young's double-slit experiment, when $( \pi d / \lambda ) \sin \theta$ is an odd half-multiple of $\pi ( \pi / 2,3 \pi / 2,5 \pi / 2 )$ the intensity at the viewing screen

Accepted Answer

A)  is a maximum. 
B)  is a minimum. 
C)  is halfway between the maximum and minimum. 
D)  cannot be determined we need $d , \lambda , \text { and } \theta$ 
A)  is a maximum. 
B)  is a minimum. 
C)  is halfway between the maximum and minimum. 
D)  cannot be determined we need $d , \lambda , \text { and } \theta$

Question 9

Red light having a wavelength of 690 nm (in air) is vertically incident on a thin film of oil that has an index of refraction of 1.19. The film of oil floats above water (having an index of refraction of 1.30). The red light is brightly reflected. The minimum (nonzero) thickness of the film of oil is

Accepted Answer

A)  290 nm. 
B)  345 nm. 
C)  580 nm. 
D)  145 nm. 
A)  290 nm. 
B)  345 nm. 
C)  580 nm. 
D)  145 nm.

Question 10

An electric field phasor of length 2300 V/m makes an angle of $\omega t = 30 ^ { \circ }$ relative to the x axis. What is the instantaneous value of the electric field?

Accepted Answer

A)  2000 V/m 
B)  1200 V/m 
C)  1300 V/m 
D)  2300 V/m 
A)  2000 V/m 
B)  1200 V/m 
C)  1300 V/m 
D)  2300 V/m

Question 11

Green light having a wavelength of 550 nm (in air) is vertically incident on a thin film of water that has an index of refraction of 1.30. The film of water rests above a plastic pane (having an index of refraction of 1.22). No green light is reflected. The minimum (nonzero) thickness of the film of water is

Accepted Answer

A)  212 nm. 
B)  450 nm. 
C)  423 nm. 
D)  108 nm. 
A)  212 nm. 
B)  450 nm. 
C)  423 nm. 
D)  108 nm.

Question 12

When reflection fringes associated with a thin film are not uniformly spaced, the reason could be nonuniformities in

Accepted Answer

A)  the film thickness. 
B)  the film index of refraction. 
C)  Both of the first two responses are valid. 
D)  Neither of the first two responses is valid. 
A)  the film thickness. 
B)  the film index of refraction. 
C)  Both of the first two responses are valid. 
D)  Neither of the first two responses is valid.

Question 13

White light shining onto a grating or onto a prism is "separated" into different colors. Contrasts include all of the following except

Accepted Answer

A)  in the grating, the whole separation sequence may be repeated at larger angles. 
B)  in the grating, the separation does not involve refraction. 
C)  in the grating, there is a central region where the colors are not separated. 
D)  Hold it! There are no exceptions. 
A)  in the grating, the whole separation sequence may be repeated at larger angles. 
B)  in the grating, the separation does not involve refraction. 
C)  in the grating, there is a central region where the colors are not separated. 
D)  Hold it! There are no exceptions.

Question 14

If two sources emit waves that are not of the same frequencies and do not remain in phase, the interference fringes produced will actually be

Accepted Answer

A)  moving in space. 
B)  moving in time. 
C)  Both of the first two responses are valid. 
D)  Hold it! Interference cannot be produced. 
A)  moving in space. 
B)  moving in time. 
C)  Both of the first two responses are valid. 
D)  Hold it! Interference cannot be produced.

Question 15

When two slits are replaced with three slits (with the same slit-to-slit spacing), all of the following changes occur in the interference fringe pattern except

Accepted Answer

A)  the angular separation between principal maxima and the adjacent points of minima is reduced. 
B)  it is no longer dark at the points where the two-slit minima were located. 
C)  the principal maxima are more closely spaced. 
D)  the principal maxima are brighter. 
A)  the angular separation between principal maxima and the adjacent points of minima is reduced. 
B)  it is no longer dark at the points where the two-slit minima were located. 
C)  the principal maxima are more closely spaced. 
D)  the principal maxima are brighter.

Question 16

When two pieces of glass are pressed together in air and illuminated with coherent light, the place where they are in contact will exhibit an appearance correctly described in one of the responses to the preceding question. The reason behind the correct answer is that

Accepted Answer

A)  the actual physical path difference between waves striking the two surfaces in contact is very close to zero. 
B)  the phase difference between waves reflected from the two surfaces is 180º. 
C)  Both of the first two responses are necessary to obtain the correct answer. 
D)  Though both of the first two responses state facts correctly, neither is relevant in explaining the correct answer to the previous question. 
A)  the actual physical path difference between waves striking the two surfaces in contact is very close to zero. 
B)  the phase difference between waves reflected from the two surfaces is 180º. 
C)  Both of the first two responses are necessary to obtain the correct answer. 
D)  Though both of the first two responses state facts correctly, neither is relevant in explaining the correct answer to the previous question.

Question 17

Green light having wavelength of 550 nm (in air) is vertically incident on a thin film of water that has an index of refraction of 1.30. The film of water rests above a plastic pane (having an index of refraction of 1.22). The green light is brightly reflected. The minimum (nonzero) thickness of the film of water is

Accepted Answer

A)  212 nm. 
B)  450 nm. 
C)  423 nm. 
D)  108 nm. 
A)  212 nm. 
B)  450 nm. 
C)  423 nm. 
D)  108 nm.

Question 18

A monochromatic source produces light at a wavelength of 510 nm in air. The wave then passes through water that has an index of refraction of 1.32. The velocity of propagation of the wave in the water is

Accepted Answer

A)  $2.27 \times 10 ^ { 8 }$ m/s. 
B)  $3.96 \times 10 ^ { 8 }$ m/s. 
C)  $2.96 \times 10 ^ { 8 }$ m/s. 
D)  $$3.00 \times 10 ^ { 8 }$$ m/s. 
A)  $2.27 \times 10 ^ { 8 }$ m/s. 
B)  $3.96 \times 10 ^ { 8 }$ m/s. 
C)  $2.96 \times 10 ^ { 8 }$ m/s. 
D)  $$3.00 \times 10 ^ { 8 }$$ m/s.

Question 19

The limiting angular separation of two points such that they can be resolved is known as

Accepted Answer

A)  Rayleigh's criterion. 
B)  Kepler's law. 
C)  Doppler's law. 
D)  Galileo's principle. 
A)  Rayleigh's criterion. 
B)  Kepler's law. 
C)  Doppler's law. 
D)  Galileo's principle.

Question 20

Consider a Young's double-slit experiment. The slits are separated by 1.2 mm, and the monochromatic light has a wavelength of 600 nm. The angular position of the first-order bright (maxima) fringe is

Accepted Answer

A)  0.054º. 
B)  0.018º. 
C)  0.029º. 
D)  0.035º. 
A)  0.054º. 
B)  0.018º. 
C)  0.029º. 
D)  0.035º.

Exam 35: Interference and Diffraction

The first angular minima location for a single-slit diffraction having slit width of 1μm1 \mu \mathrm { m }1μm and wavelength of 500 nm is

All of the following considerations are important in explaining the observed interference patterns produced by light reflection from a thin film except

Red light having a wavelength of 690 nm (in air) is vertically incident on a thin film of oil that has an index of refraction of 1.19. The film of oil floats above water (having an index of refraction of 1.30). No red light is reflected. The minimum (nonzero) thickness of the film of oil is

An electric field phasor makes an angle of ωt\omega tωt relative to the x axis. The instantaneous value of the electric field is given by the

Find the critical angle for two objects 1 meter apart when viewed using 500-nm light (assume a rectangular aperture):

The minimum film thickness for which a reflection maximum occurs is the same in all of the following situations except

In a Young's double-slit experiment, when (πd/λ)sin⁡θ( \pi d / \lambda ) \sin \theta(πd/λ)sinθ is an odd half-multiple of π(π/2,3π/2,5π/2)\pi ( \pi / 2,3 \pi / 2,5 \pi / 2 )π(π/2,3π/2,5π/2) the intensity at the viewing screen

An electric field phasor of length 2300 V/m makes an angle of ωt=30∘\omega t = 30 ^ { \circ }ωt=30∘ relative to the x axis. What is the instantaneous value of the electric field?

When reflection fringes associated with a thin film are not uniformly spaced, the reason could be nonuniformities in

White light shining onto a grating or onto a prism is "separated" into different colors. Contrasts include all of the following except

If two sources emit waves that are not of the same frequencies and do not remain in phase, the interference fringes produced will actually be

When two slits are replaced with three slits (with the same slit-to-slit spacing), all of the following changes occur in the interference fringe pattern except

When two pieces of glass are pressed together in air and illuminated with coherent light, the place where they are in contact will exhibit an appearance correctly described in one of the responses to the preceding question. The reason behind the correct answer is that

A monochromatic source produces light at a wavelength of 510 nm in air. The wave then passes through water that has an index of refraction of 1.32. The velocity of propagation of the wave in the water is

The limiting angular separation of two points such that they can be resolved is known as

Consider a Young's double-slit experiment. The slits are separated by 1.2 mm, and the monochromatic light has a wavelength of 600 nm. The angular position of the first-order bright (maxima) fringe is

Space, Time, and Mass

Motion Along a Straight Line

Vectors

Motion in Two and Three Dimensions

Newtons Laws of Motion

Further Applications of Newtons Laws

Work and Energy

Conservation of Energy

Gravitation

Systems of Particles

Collisions

Rotation of a Rigid Body

Dynamics of a Rigid Body

Statics and Elasticity

Oscillations

Waves

Sound

Fluid Mechanics

The Ideal Gas

Heat

Thermodynamics

Electric Force and the Electric Charge

The Electric Field

Gauss Law

Electrostatic Potential and Energy

Capacitors and Dielectrics

Currents and Ohms Law

Direct Current Circuits

Magnetic Force and Field

Charges and Currents in Magnetic Fields

Electromagnetic Induction

Alternating Current Circuits

Electromagnetic Waves

Reflection, Refraction, and Optics

The Theory of Special Relativity

Quanta of Light

Spectral Lines, Bohrs Theory, and Quantum Mechanics

Quantum Structure of Atoms, Molecules, and Solids

Nuclei

Elementary Particles and Cosmology

Filters

The first angular minima location for a single-slit diffraction having slit width of $1 \mu \mathrm { m }$ and wavelength of 500 nm is

An electric field phasor makes an angle of $\omega t$ relative to the x axis. The instantaneous value of the electric field is given by the

In a Young's double-slit experiment, when $( \pi d / \lambda ) \sin \theta$ is an odd half-multiple of $\pi ( \pi / 2,3 \pi / 2,5 \pi / 2 )$ the intensity at the viewing screen

An electric field phasor of length 2300 V/m makes an angle of $\omega t = 30 ^ { \circ }$ relative to the x axis. What is the instantaneous value of the electric field?