Question 1

A Young's double-slit experiment is performed in air and then the apparatus is submerged in water. What happens to the fringe separation, and what can be used to explain the change, if any?

Accepted Answer

The fringe separation decreases because the wavelength of light decreases when it enters a medium with a higher refractive index, like water. The frequency remains constant, but the speed of light and wavelength decrease in the medium.

Question 2

When light passes from a material with a low index of refraction into material with a high index of refraction:

Accepted Answer

When light passes from a material with a low index of refraction into material with a high index of refraction, some light is reflected with a 180° change of phase. This is known as the phenomenon of total internal reflection.

Question 3

A surface is coated with a material having index of refraction 1.50. If light in air has a wavelength of 450 nm and is normally incident on this surface, and it is found through interference effects with this light that the surface is 15 wavelengths thick, which of the following is the thickness of the surface?

Accepted Answer

The answer of A surface is coated with a material...

Question 4

A soap bubble (n = 1.35) is floating in air. If the thickness of the bubble wall is 322 nm, which of the following wavelengths of visible light is strongly reflected?

Accepted Answer

The answer of A soap bubble (n = 1.35) is...

Question 5

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 wavelength 490 nm illuminates the top plate. If 20 dark bands are counted across the top plate, what is the paper thickness? (1 nm = 10 ^- ⁹ m) Note that a dark band occurs where the plates contact.

Accepted Answer

The answer of Two flat glass plates are in contact...

Question 6

A thin film (  ) of thickness 77.6 nm, applied to a camera lens (  ), is the minimum thickness that results in destructive interference for reflected light of wavelength 450 nm. which of the following is the next greater thickness that will also give destructive interference for this wavelength?

Accepted Answer

The answer of A thin film (  ) of...

Question 7

A silicon monoxide (n = 1.45) film of 108 nm thickness is used to coat a glass camera lens (n = 1.56). What wavelength of light in the visible region (390 to 710 nm) will be most efficiently transmitted by this system? (1 nm = 10 ^- ⁹ m)

Accepted Answer

The answer of A silicon monoxide (n = 1.45) film...

Question 8

A possible means for making an airplane radar-invisible is to coat the plane with an antireflective polymer. If radar waves have a wavelength of 3.84 cm, and the index of refraction of the polymer is n = 1.6, how thick would the coating be if a 180° phase change occurs at both surfaces?

Accepted Answer

The answer of A possible means for making an airplane...

Question 9

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 strongly reflects light with a wavelength of 497 nm?

Accepted Answer

We can use the equation for the reflection coefficient at an interface between two media:

R = ((n1 - n2)/(n1 + n2))^2

where n1 and n2 are the indices of refraction of the two media.

For strong reflection, the reflection coefficient is close to 1, so we can set R = 1 and solve for the thickness of the oil layer:

1 = ((1.33 - 1.20)/(1.33 + 1.20))^2 * (4*pi*k/lambda)

where k is an integer (1, 2, 3, etc.) and lambda is the wavelength of the reflected light. We can solve for the thickness of the oil layer by plugging in k = 1 and lambda = 497 nm:

t = lambda/(4*n*tan(arccos(sqrt(R))))

t = (497 nm)/(4*1.20*tan(arccos(sqrt(1))))

t = 0.207 µm = 207 nm

Therefore, the thickness of the oil layer in the region that strongly reflects light with a wavelength of 497 nm is 207 nm. Answer choice A is correct.

Question 10

Interference effects observed in the early 1800s were instrumental in supporting a concept of the existence of which property of light?

Accepted Answer

Interference effects, such as those observed in Thomas Young's double-slit experiment, provided strong evidence for the wave nature of light, as they demonstrated that light can exhibit wave-like behavior, such as constructive and destructive interference.

Question 11

Upon reflection, light undergoes no phase change:

Accepted Answer

The answer of Upon reflection, light undergoes no phase change:
...

Question 12

A Young's double slit has a slit separation of 2.50 *10 ^- ⁵ m on which a monochromatic light beam is directed. The resultant bright fringes on a screen 1.00 m from the double slit are separated by 2.30 *10 sup>- ²m. What is the wavelength of this beam? (1 nm = 10 ^- ⁹ m)

Accepted Answer

The correct answer is A because the wavelength of the beam can be calculated using the formula:λ = d * sin(θ) / mwhere d is the slit separation, θ is the angle of the bright fringe from the central fringe, and m is the order of the bright fringe. In this case, d = 2.50 * 10^-5 m, θ = tan^-1(2.30 * 10^-2 m / 1.00 m) = 0.023 rad, and m = 1. Plugging these values into the formula, we get:λ = (2.50 * 10^-5 m) * sin(0.023 rad) / 1= 5.75 * 10^-7 m= 575 nm

Question 13

Two narrow slits are 0.025 mm apart. When a laser shines on them, bright fringes form on a screen that is a meter away. These fringes are 1.3 cm apart. What is the separation between the m = 2 bright fringe and the central fringe?

Accepted Answer

The answer of Two narrow slits are 0.025 mm apart....

Question 14

Light is reflecting off a wedge-shaped thin piece of glass producing bright and dark interference fringes. If a certain location has a bright fringe, a nearby point will have a bright fringe if the thickness of the glass increases by:

Accepted Answer

For constructive interference (bright fringe), the path difference must be an integer multiple of the wavelength. An increase in thickness by 1/2 of a wavelength will result in the same condition for constructive interference at a nearby point.

Question 15

If a wave from one slit of a Young's double-slit set-up arrives at a point on the screen one-half wavelength behind the wave from the other slit, what is observed at that point?

Accepted Answer

When waves from different slits arrive at a point on the screen out of phase by half wavelength, destructive interference occurs and a dark fringe is observed at that point.

Question 16

A hair is placed at one edge between two flat glass plates. When this arrangement is illuminated with yellow light of wavelength ($\lambda$= 600 nm), a total of 61 dark bands are counted starting at the point of contact between the plates. How thick is the hair? (1 nm = 10 ^- ⁹ m) Note that a dark band occurs where the plates contact.

Accepted Answer

The answer of A hair is placed at one edge...

Question 17

That all points on a wave front act as new sources of spherical waves is attributed to:

Accepted Answer

This principle is known as Huygens' principle, named after Dutch physicist Christiaan Huygens.

Question 18

In a Young's double-slit experiment, both the wavelength and the slit separation are increased by 25%. What happens to the distance between two adjacent bright fringes?

Accepted Answer

The distance between two adjacent bright fringes is given by d = λD/d, where λ is the wavelength, D is the distance from the slits to the screen, and d is the slit separation. As both λ and d are increased by the same percentage, the ratio λ/d remains the same, and therefore the distance between adjacent bright fringes will stay the same.

Question 19

Two thin layers of material with different indices of refraction are coated on a glass plate. The outer first material has n₁ = 1.404, the inner second material has n₂ = 1.176, and the glass has n_glass = 1.62. If light is incident from air on the first layer, what is the phase change relative to that of the first layer reflection for light that reflects from the glass?

Accepted Answer

The answer of Two thin layers of material with different...

Question 20

In a Young's double-slit experiment, what happens to the angular separation between the fringes when the wavelength is decreased at the same time that the slit separation is increased?

Accepted Answer

The angular separation between the fringes is given by the formula θ = λ/d, where λ is the wavelength and d is the slit separation. Decreasing the wavelength and increasing the slit separation both lead to a decrease in angular separation.

Quiz 25: Wave Optics

A Young's double-slit experiment is performed in air and then the apparatus is submerged in water. What happens to the fringe separation, and what can be used to explain the change, if any?

When light passes from a material with a low index of refraction into material with a high index of refraction:

A soap bubble (n = 1.35) is floating in air. If the thickness of the bubble wall is 322 nm, which of the following wavelengths of visible light is strongly reflected?

A thin film ( ) of thickness 77.6 nm, applied to a camera lens ( ) , is the minimum thickness that results in destructive interference for reflected light of wavelength 450 nm. which of the following is the next greater thickness that will also give destructive interference for this wavelength?

A silicon monoxide (n = 1.45) film of 108 nm thickness is used to coat a glass camera lens (n = 1.56) . What wavelength of light in the visible region (390 to 710 nm) will be most efficiently transmitted by this system? (1 nm = 10 ^- ⁹ m)

A possible means for making an airplane radar-invisible is to coat the plane with an antireflective polymer. If radar waves have a wavelength of 3.84 cm, and the index of refraction of the polymer is n = 1.6, how thick would the coating be if a 180° phase change occurs at both surfaces?

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 strongly reflects light with a wavelength of 497 nm?

Interference effects observed in the early 1800s were instrumental in supporting a concept of the existence of which property of light?

Upon reflection, light undergoes no phase change:

A Young's double slit has a slit separation of 2.50 10 ^- ⁵ m on which a monochromatic light beam is directed. The resultant bright fringes on a screen 1.00 m from the double slit are separated by 2.30 10 sup>- ²m. What is the wavelength of this beam? (1 nm = 10 ^- ⁹ m)

Two narrow slits are 0.025 mm apart. When a laser shines on them, bright fringes form on a screen that is a meter away. These fringes are 1.3 cm apart. What is the separation between the m = 2 bright fringe and the central fringe?

Light is reflecting off a wedge-shaped thin piece of glass producing bright and dark interference fringes. If a certain location has a bright fringe, a nearby point will have a bright fringe if the thickness of the glass increases by:

If a wave from one slit of a Young's double-slit set-up arrives at a point on the screen one-half wavelength behind the wave from the other slit, what is observed at that point?

That all points on a wave front act as new sources of spherical waves is attributed to:

In a Young's double-slit experiment, both the wavelength and the slit separation are increased by 25%. What happens to the distance between two adjacent bright fringes?

In a Young's double-slit experiment, what happens to the angular separation between the fringes when the wavelength is decreased at the same time that the slit separation is increased?

Quiz 25: Wave Optics

A Young's double-slit experiment is performed in air and then the apparatus is submerged in water. What happens to the fringe separation, and what can be used to explain the change, if any?

When light passes from a material with a low index of refraction into material with a high index of refraction:

A soap bubble (n = 1.35) is floating in air. If the thickness of the bubble wall is 322 nm, which of the following wavelengths of visible light is strongly reflected?

A thin film ( ) of thickness 77.6 nm, applied to a camera lens ( ) , is the minimum thickness that results in destructive interference for reflected light of wavelength 450 nm. which of the following is the next greater thickness that will also give destructive interference for this wavelength?

A silicon monoxide (n = 1.45) film of 108 nm thickness is used to coat a glass camera lens (n = 1.56) . What wavelength of light in the visible region (390 to 710 nm) will be most efficiently transmitted by this system? (1 nm = 10 - 9 m)

A possible means for making an airplane radar-invisible is to coat the plane with an antireflective polymer. If radar waves have a wavelength of 3.84 cm, and the index of refraction of the polymer is n = 1.6, how thick would the coating be if a 180° phase change occurs at both surfaces?

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 strongly reflects light with a wavelength of 497 nm?

Interference effects observed in the early 1800s were instrumental in supporting a concept of the existence of which property of light?

Upon reflection, light undergoes no phase change:

A Young's double slit has a slit separation of 2.50 *10 - 5 m on which a monochromatic light beam is directed. The resultant bright fringes on a screen 1.00 m from the double slit are separated by 2.30 *10 sup>- 2 m. What is the wavelength of this beam? (1 nm = 10 - 9 m)

Two narrow slits are 0.025 mm apart. When a laser shines on them, bright fringes form on a screen that is a meter away. These fringes are 1.3 cm apart. What is the separation between the m = 2 bright fringe and the central fringe?

Light is reflecting off a wedge-shaped thin piece of glass producing bright and dark interference fringes. If a certain location has a bright fringe, a nearby point will have a bright fringe if the thickness of the glass increases by:

If a wave from one slit of a Young's double-slit set-up arrives at a point on the screen one-half wavelength behind the wave from the other slit, what is observed at that point?

That all points on a wave front act as new sources of spherical waves is attributed to:

In a Young's double-slit experiment, both the wavelength and the slit separation are increased by 25%. What happens to the distance between two adjacent bright fringes?

In a Young's double-slit experiment, what happens to the angular separation between the fringes when the wavelength is decreased at the same time that the slit separation is increased?

A silicon monoxide (n = 1.45) film of 108 nm thickness is used to coat a glass camera lens (n = 1.56) . What wavelength of light in the visible region (390 to 710 nm) will be most efficiently transmitted by this system? (1 nm = 10 ^- ⁹ m)

A Young's double slit has a slit separation of 2.50 10 ^- ⁵ m on which a monochromatic light beam is directed. The resultant bright fringes on a screen 1.00 m from the double slit are separated by 2.30 10 sup>- ²m. What is the wavelength of this beam? (1 nm = 10 ^- ⁹ m)