Question 1

Two flat glass plates are in contact along one end and are separated by a sheet of paper 4.0 x 10^-6 m thick at the other end.The top plate is illuminated by a monochromatic light source of wavelength 490 nm.How many dark parallel bands will be evident across the top plate? (1 nm = 10^-9 m) A)7 B)9 C)13 D)17

Accepted Answer

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

Question 2

The dark spot observed in the center of a Newton's rings pattern is attributed to which of the following?
A)polarization of light when reflected
B)polarization of light when refracted
C)phase shift of light when reflected
D)phase shift of light when refracted

Accepted Answer

The dark spot in the center of a Newton's rings pattern is caused by destructive interference between the light waves reflecting off the top and bottom surfaces of the thin film. This results in a phase shift of the reflected light waves, which causes them to cancel each other out at the center of the pattern, creating a dark spot. Therefore, the correct option is the phase shift of light when reflected.

Question 3

A beam of light of wavelength 650 nm is incident along the normal to two closely spaced parallel glass plates.For what air gap separation between the plates will the transmitted beam be of maximum intensity? (1 nm = 10^-9 m) A)81 nm B)163 nm C)325 nm D)488 nm

Accepted Answer

The condition for maximum intensity in transmitted light through thin film interference is when the path difference is an integral multiple of the wavelength. For normal incidence, the path difference is twice the air gap. Thus, 2d = mλ, where m is an integer. For maximum intensity, m = 1, so d = λ/2 = 650 nm / 2 = 325 nm.

Question 4

A silicon monoxide thin film (n = 1.45)of thickness 90.0 nm is applied to a camera lens made of glass (n = 1.55).This will result in a destructive interference for reflected light of what wavelength?
A)720 nm
B)558 nm
C)522 nm
D)450 nm

Accepted Answer

We can use the formula for the thickness of a thin film causing destructive interference for reflected light:

t = (m + 1/2)λ / (2n)

where t is the thickness of the film, λ is the wavelength of light, n is the refractive index of the film, and m is the number of the interference order.

For destructive interference, m is an odd integer. We can rearrange the formula to solve for λ:

λ = 2nt / (m + 1/2)n

For the given values,

t = 90.0 nm
n1 = 1.45 (refractive index of the silicon monoxide film)
n2 = 1.55 (refractive index of the glass lens)

We want destructive interference, so we can use m = 1. Plugging in the values,

λ = 2(1.45)(90.0 nm) / (1 + 1/2)(1.55) = 522 nm

Therefore, the wavelength of light that will experience destructive interference is 522 nm, so the answer is C.

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 21 dark bands are counted across the top plate,what is the paper thickness? (1 nm = 10^-9 m) A)2.7 x 10^-6m B)3.4 x 10^-6 m C)4.9 x 10^-6 m D)5.8 x 10^-6 m

Accepted Answer

The thickness of the tissue paper can be found using the formula 
t = (m + 1/2) λ/2n
where t is the thickness of the tissue paper, λ is the wavelength of light, n is the refractive index of tissue paper, and m is the number of dark fringes observed.

Here, λ = 490 nm and m = 21.
The refractive index of tissue paper is not given, but it is assumed to be close to that of air, which is 1.

Substituting the values in the formula, we get
t = (21 + 1/2) × 490 × 10^-9 /(4 × 10^-6)
t = 4.9 × 10^-6 m
Converting to scientific notation and rounding off to two significant figures, we get
t = 4.9 × 10^-6 m = 4.9 μm = 4.9 x 10^-3 mm
 
Therefore, the best choice is C, which is 4.9 x 10^-6 m in scientific notation.

Question 6

The center spot of Newton's rings is dark.This destructive interference occurs because:
A)the two beams travel distances that are different by half a wavelength.
B)both waves change phase by 180 $\degree$ as they are reflected.
C)one beam changes phase by 180 $\degree$ when it is reflected.
D)both waves have a trough.

Accepted Answer

When light reflects off a medium with a higher refractive index, it undergoes a phase change of 180 degrees (half a wavelength). In Newton's rings, the light reflecting off the top surface of the air film does not undergo a phase change, while the light reflecting off the bottom surface (glass) does, leading to destructive interference at the center.

Question 7

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 dark fringe if the thickness of the glass increases by:
A)1/8 of a wavelength of the light.
B)1/4 of a wavelength of the light.
C)1/2 of a wavelength of the light.
D)one wavelength of the light.

Accepted Answer

The spacing between bright and dark fringes in a wedge interferometer is given by:

d = λ / 2nθ

where λ is the wavelength of light, n is the refractive index of the glass, and θ is the angle of the wedge. If the thickness of the glass at a certain location produces a bright fringe, then the thickness must satisfy the condition:

t = mλ / 2n

where m is an integer. If the thickness increases by Δt, then the new thickness is:

t' = (m + 1/2)λ / 2n

For a nearby point to have a dark fringe, the new thickness must satisfy the condition:

t' = (m + 1)λ / 2n

Subtracting the two equations, we get:

Δt = λ / 4n

Therefore, the thickness must increase by 1/4 of a wavelength for a nearby point to have a dark fringe.

Question 8

What wavelength monochromatic source in the visible region (390 to 710 nm)can be used to constructively reflect off a soap film (n = 1.46)if the film is 77 nm thick?
A)409 nm
B)430 nm
C)450 nm
D)558 nm

Accepted Answer

The answer of What wavelength monochromatic source in the visible...

Question 9

A silicon monoxide (n = 1.45)film of 270 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)409 nm B)492 nm C)522 nm D)638 nm

Accepted Answer

To find the wavelength of light that will be most efficiently transmitted, we need to use the equation for thin film interference:

2nt = mλ

where n is the refractive index of the film, t is the thickness of the film, m is an integer representing the order of the interference, and λ is the wavelength of light.

We want to find the wavelength of light that will have constructive interference (i.e. will be most efficiently transmitted), so we need to find the value of λ that satisfies the equation above for m = 1.

Plugging in the given values, we get:

2(1.45)(270 nm) = (1)(λ)

Solving for λ gives:

λ = 522 nm

Therefore, the wavelength of light in the visible region that will be most efficiently transmitted by this system is 522 nm, so the answer is C).

Question 10

In a Young's experiment,the paths from the slits to a point on the screen differ in length,causing destructive interference at the point.Which of the following path difference would cause this destructive interference?
A)5ë/2
B)3ë/4
C)4ë
D)None of the above.

Accepted Answer

The answer of In a Young's experiment,the paths from the...

Question 11

Light of wavelength 500 nm shines on a soap bubble film (n = 1.46).For what soap film thickness,other than the minimum thickness,will constructive interference occur?
A)63 nm
B)86 nm
C)172 nm
D)257 nm

Accepted Answer

The answer of Light of wavelength 500 nm shines on...

Question 12

When light passes from a material with a high index of refraction into material with a low index of refraction:
A)none of the light is reflected.
B)some light is reflected without a change of phase.
C)some light is reflected with a 180 $\degree$ change of phase.
D)the light that is not reflected has a 180 $\degree$change of phase.

Accepted Answer

When light passes from a material with a high index of refraction to one with a lower index, some light is reflected without a change of phase.

Question 13

The blue tint of a coated camera lens is largely caused by what effects?
A)diffraction
B)refraction
C)polarization
D)interference

Accepted Answer

The blue tint of a coated camera lens is primarily due to interference effects. Thin-film interference occurs when light waves reflected off the top and bottom surfaces of the lens coating interfere with each other, enhancing some wavelengths of light and reducing others, which can give the lens a colorful appearance, often blue.

Question 14

What wavelength monochromatic source in the visible region (390 to 710 nm)can be used to constructively reflect off a soap film (n = 1.46)if the film is 240 nm thick?
A)467 nm
B)562 nm
C)587 nm
D)480 nm

Accepted Answer

Constructive interference occurs when the path length difference between two waves is an integer multiple of the wavelength. In this case, the path length difference is twice the thickness of the soap film, or 480 nm. Therefore, the wavelength of the monochromatic source must be 480 nm / 2 = 240 nm. The only choice that is close to this value is 467 nm.

Question 15

What is the minimum thickness of a glycerin film (n = 1.47)on which light of wavelength 600 nm shines that results in constructive interference of the reflected light? Assume the film is surrounded front and back by air.
A)75 nm
B)102 nm
C)150 nm
D)204 nm

Accepted Answer

For constructive interference to occur, the thickness of the film must be equal to an integer multiple of half the wavelength of the reflected light. In this case, the reflected light will have a wavelength of 600 nm in air and a shorter wavelength of 411 nm in the glycerin film (due to the higher refractive index of glycerin).

So,

(2t/λ) = m

Where t is the thickness of the glycerin film, λ is the wavelength of the reflected light in air, and m is an integer.

Rearranging this equation, we get:

t = mλ/2n

Where n is the refractive index of glycerin.

Plugging in the values, we get:

t = (1/2) * 600 nm / 1.47 = 204 nm / 2 = 102 nm

Therefore, the minimum thickness of the glycerin film for constructive interference is 102 nm.

The correct choice is B.

Question 16

In a Young's double-slit experiment,how many maxima occur between the 4^th order maxima? A)6 B)7 C)8 D)Three more than the number of minima.

Accepted Answer

The number of maxima between any two order maxima is given by (m+1), where m is the order number of the first maximum. Thus, between the 4th order maximum and the 1st order maximum, there are (4-1+1) = 4 maxima. Similarly, between the 1st order maximum and the 0th order maximum, there are (1-0+1) = 2 maxima. So, the total number of maxima between the 4^th order maxima is 4+2 = 6, which corresponds to option B.

Question 17

When light shines on a lens placed on a flat piece of glass,interference occurs which causes circular fringes called Newton's rings.The two beams that are interfering come:
A)from the top and bottom surface of the lens.
B)from the top surface of the lens and the top surface of the piece of glass.
C)from the bottom surface of the lens and the top surface of the piece of glass.
D)from the top and bottom surface of the flat piece of glass.

Accepted Answer

The two beams that are interfering come from the bottom surface of the lens and the top surface of the piece of glass. This is because the light that passes through the lens is refracted and changes direction before it reaches the flat glass surface, causing interference between the two waves. The interference pattern produces circular fringes that get closer together near the center of the rings.

Question 18

A silicon monoxide (n = 1.45)film of 100 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)400 nm B)492 nm C)624 nm D)580 nm

Accepted Answer

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

Question 19

Laser light sent through a double slit produces an interference patter on a screen 3.00 m from the slits.If the second order maximum occurs at an angle of 12.0 $\degree$,at what angle does the eighth order maximum occur?
A)No eighth order maximum occurs.
B)48.0 $\degree$
C)56.3 $\degree$
D)Not enough information is given.

Accepted Answer

The angle for the nth order maximum for a double slit interference pattern is given by sinθ = nλ/d, where λ is the wavelength of the light and d is the distance between the slits. Since the second order maximum occurs at an angle of 12.0°, we can use this equation to find the wavelength: sin12.0° = 2λ/d. Rearranging, λ = d sin12.0°/2. For the eighth order maximum, n = 8, so sinθ = 8λ/d. Substituting in the expression for λ and solving for sinθ, we get sinθ = 8(d sin12.0°/2)/d = 4sin12.0° = 0.83. Therefore, the angle for the eighth order maximum is sin⁻¹(0.83) ≈ 56.3°, which corresponds to choice C.

Question 20

Two closely spaced parallel glass plates are separated by 750 nm.What wavelength light source in the visible region (390 nm to 710 nm)will experience maximum transmission through the two plates?
A)500 nm
B)429 nm
C)600 nm
D)684 nm

Accepted Answer

The wavelength of light that experiences maximum transmission through the two plates is equal to twice the thickness of the plates. Therefore, the correct answer is A) 500 nm.

Quiz 24: Wave Optics

Two flat glass plates are in contact along one end and are separated by a sheet of paper 4.0 x 10^-6 m thick at the other end.The top plate is illuminated by a monochromatic light source of wavelength 490 nm.How many dark parallel bands will be evident across the top plate? (1 nm = 10^-9 m)

The dark spot observed in the center of a Newton's rings pattern is attributed to which of the following?

A beam of light of wavelength 650 nm is incident along the normal to two closely spaced parallel glass plates.For what air gap separation between the plates will the transmitted beam be of maximum intensity? (1 nm = 10^-9 m)

A silicon monoxide thin film (n = 1.45) of thickness 90.0 nm is applied to a camera lens made of glass (n = 1.55) .This will result in a destructive interference for reflected light of what wavelength?

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 21 dark bands are counted across the top plate,what is the paper thickness? (1 nm = 10^-9 m)

The center spot of Newton's rings is dark.This destructive interference occurs because:

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 dark fringe if the thickness of the glass increases by:

What wavelength monochromatic source in the visible region (390 to 710 nm) can be used to constructively reflect off a soap film (n = 1.46) if the film is 77 nm thick?

A silicon monoxide (n = 1.45) film of 270 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)

In a Young's experiment,the paths from the slits to a point on the screen differ in length,causing destructive interference at the point.Which of the following path difference would cause this destructive interference?

Light of wavelength 500 nm shines on a soap bubble film (n = 1.46) .For what soap film thickness,other than the minimum thickness,will constructive interference occur?

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

The blue tint of a coated camera lens is largely caused by what effects?

What wavelength monochromatic source in the visible region (390 to 710 nm) can be used to constructively reflect off a soap film (n = 1.46) if the film is 240 nm thick?

What is the minimum thickness of a glycerin film (n = 1.47) on which light of wavelength 600 nm shines that results in constructive interference of the reflected light? Assume the film is surrounded front and back by air.

In a Young's double-slit experiment,how many maxima occur between the 4^th order maxima?

When light shines on a lens placed on a flat piece of glass,interference occurs which causes circular fringes called Newton's rings.The two beams that are interfering come:

A silicon monoxide (n = 1.45) film of 100 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)

Laser light sent through a double slit produces an interference patter on a screen 3.00 m from the slits.If the second order maximum occurs at an angle of 12.0 $\degree$ ,at what angle does the eighth order maximum occur?

Two closely spaced parallel glass plates are separated by 750 nm.What wavelength light source in the visible region (390 nm to 710 nm) will experience maximum transmission through the two plates?