Question 1

The largest x-ray wavelength that can be diffracted by crystal planes with a separation of 0.316 nm is:

Accepted Answer

A) 0.158 nm 
B) 0.316 nm 
C) 0.474 nm 
D) 0.632 nm 
E) 1.26 nm 
A) 0.158 nm 
B) 0.316 nm 
C) 0.474 nm 
D) 0.632 nm 
E) 1.26 nm

Question 2

In the equation sin$\theta$= $\lambda$/a for single-slit diffraction,$\theta$is:

Accepted Answer

A) the angle to the first minimum 
B) the angle to the second maximum 
C) the phase angle between the extreme rays 
D) N $\pi$ where N is an integer 
E) (N + 1/2) $\pi$where N is an integer 
A) the angle to the first minimum 
B) the angle to the second maximum 
C) the phase angle between the extreme rays 
D) N $\pi$ where N is an integer 
E) (N + 1/2) $\pi$where N is an integer

Question 3

Two slits in an opaque barrier each have a width of 0.020 mm and are separated by 0.050 mm.When coherent monochromatic light passes through the slits the number of interference maxima within the central diffraction maximum:

Accepted Answer

A) is 1 
B) is 2 
C) is 4 
D) is 5 
E) cannot be determined unless the wavelength is given 
A) is 1 
B) is 2 
C) is 4 
D) is 5 
E) cannot be determined unless the wavelength is given

Question 4

The shimmering or wavy lines that can often be seen near the ground on a hot day are due to:

Accepted Answer

A) Brownian movement 
B) reflection 
C) refraction 
D) diffraction 
E) dispersion 
A) Brownian movement 
B) reflection 
C) refraction 
D) diffraction 
E) dispersion

Question 5

In a double-slit diffraction experiment the number of interference fringes within the central diffraction maximum can be increased by:

Accepted Answer

A) increasing the wavelength 
B) decreasing the wavelength 
C) increasing the slit separation 
D) decreasing the slit width 
E) increasing the slit width 
A) increasing the wavelength 
B) decreasing the wavelength 
C) increasing the slit separation 
D) decreasing the slit width 
E) increasing the slit width

Question 6

Two nearly equal wavelengths of light are incident on an N slit grating.The two wavelengths are not resolvable.When N is increased they become resolvable.This is because:

Accepted Answer

A) more light gets through the grating 
B) the lines get more intense 
C) the entire pattern spreads out 
D) there are more orders present 
E) the lines become more narrow 
A) more light gets through the grating 
B) the lines get more intense 
C) the entire pattern spreads out 
D) there are more orders present 
E) the lines become more narrow

Question 7

Two stars that are close together are photographed through a telescope.The black and white film is equally sensitive to all colors.Which situation would result in the most clearly separated images of the stars?

Accepted Answer

A) Small lens, red stars 
B) Small lens, blue stars 
C) Large lens, red stars 
D) Large lens, blue stars 
E) Large lens, one star red and the other blue 
A) Small lens, red stars 
B) Small lens, blue stars 
C) Large lens, red stars 
D) Large lens, blue stars 
E) Large lens, one star red and the other blue

Question 8

A diffraction pattern is produced on a viewing screen by illuminating a long narrow slit with light of wavelength $\lambda$.If $\lambda$ is increased and no other changes are made:

Accepted Answer

A) the intensity at the center of the pattern decreases and the pattern expands away from the bright center 
B) the intensity at the center of the pattern increases and the pattern contracts toward the bright center 
C) the intensity at the center of the pattern does not change and the pattern expands away from the bright center 
D) the intensity at the center of the pattern does not change and the pattern contracts toward the bright center 
E) neither the intensity at the center of the pattern nor the pattern itself change 
A) the intensity at the center of the pattern decreases and the pattern expands away from the bright center 
B) the intensity at the center of the pattern increases and the pattern contracts toward the bright center 
C) the intensity at the center of the pattern does not change and the pattern expands away from the bright center 
D) the intensity at the center of the pattern does not change and the pattern contracts toward the bright center 
E) neither the intensity at the center of the pattern nor the pattern itself change

Question 9

In the equation d sin$\theta$= m$\lambda$ for the lines of a diffraction grating, d is:

Accepted Answer

A) the number of slits 
B) the slit width 
C) the slit separation 
D) the order of the line 
E) the index of refraction 
A) the number of slits 
B) the slit width 
C) the slit separation 
D) the order of the line 
E) the index of refraction

Question 10

Diffraction plays an important role in which of the following phenomena?

Accepted Answer

A) The sun appears as a disk rather than a point to the naked eye 
B) Light is bent as it passes through a glass prism 
C) A cheerleader yells through a megaphone 
D) A farsighted person uses eyeglasses of positive focal length 
E) A thin soap film exhibits colors when illuminated with white light 
A) The sun appears as a disk rather than a point to the naked eye 
B) Light is bent as it passes through a glass prism 
C) A cheerleader yells through a megaphone 
D) A farsighted person uses eyeglasses of positive focal length 
E) A thin soap film exhibits colors when illuminated with white light

Question 11

Light of wavelength $\lambda$ is normally incident on a diffraction grating G.On the screen S, the central line is at P and the first order line is at Q, as shown.The distance between adjacent slits in the grating is:

Accepted Answer

A) 3$\lambda$/5 
B) 3$\lambda$/4 
C) 4$\lambda$/5 
D) 5$\lambda$/4 
E) 5$\lambda$/3 
A) 3$\lambda$/5 
B) 3$\lambda$/4 
C) 4$\lambda$/5 
D) 5$\lambda$/4 
E) 5$\lambda$/3

Question 12

As more slits with the same spacing are added to a multiple-slit system the lines:

Accepted Answer

A) spread further apart 
B) move closer together 
C) become wider 
D) become narrower 
E) do not change in position or width 
A) spread further apart 
B) move closer together 
C) become wider 
D) become narrower 
E) do not change in position or width

Question 13

A light spectrum is formed on a screen using a diffraction grating.The entire apparatus (source, grating and screen)is now immersed in a liquid of index 1.33.As a result, the pattern on the screen:

Accepted Answer

A) remains the same 
B) spreads out 
C) crowds together 
D) becomes reversed, with the previously blue end becoming red 
E) disappears because the index isn't an integer 
A) remains the same 
B) spreads out 
C) crowds together 
D) becomes reversed, with the previously blue end becoming red 
E) disappears because the index isn't an integer

Question 14

The intensity of the single-slit diffraction pattern at any angle θ is given by   .For light of wavelength 480 nm falling on a slit of width 3.5 µm, what is the value of α when θ = 18°?

Accepted Answer

A) 0.31 rad 
B) 2.3 rad 
C) 7.1 rad 
D) 7.3 rad 
E) 9.8 rad 
A) 0.31 rad 
B) 2.3 rad 
C) 7.1 rad 
D) 7.3 rad 
E) 9.8 rad

Question 15

When a highly coherent beam of light is directed against a very fine wire, the shadow formed behind it is not just that of a single wire but rather looks like the shadow of several parallel wires.The explanation of this involves:

Accepted Answer

A) refraction 
B) diffraction 
C) reflection 
D) Doppler effect 
E) an optical illusion 
A) refraction 
B) diffraction 
C) reflection 
D) Doppler effect 
E) an optical illusion

Question 16

Monochromatic light is normally incident on a diffraction grating that is 1 cm wide and has 10,000 slits.The first order line is deviated at a 30° angle.What is the wavelength of the incident light?

Accepted Answer

A) 300 nm 
B) 400 nm 
C) 500 nm 
D) 600 nm 
E) 1000 nm 
A) 300 nm 
B) 400 nm 
C) 500 nm 
D) 600 nm 
E) 1000 nm

Question 17

Monochromatic light is normally incident on a diffraction grating.The mth order line is at an angle of diffraction $\theta$and has width w.A wide single slit is now placed in front of the grating and its width is then slowly reduced.As a result:

Accepted Answer

A) "both $\theta$and w increase" 
B) "both$\theta$and w decrease" 
C) "$\theta$remains the same and w increases" 
D) "$\theta$remains the same and w decreases" 
E) "$\theta$decreases and w increases" 
A) "both $\theta$and w increase" 
B) "both$\theta$and w decrease" 
C) "$\theta$remains the same and w increases" 
D) "$\theta$remains the same and w decreases" 
E) "$\theta$decreases and w increases"

Exam 36: Diffraction

The largest x-ray wavelength that can be diffracted by crystal planes with a separation of 0.316 nm is:

In the equation sin θ\thetaθ = λ\lambdaλ /a for single-slit diffraction, θ\thetaθ is:

Two slits in an opaque barrier each have a width of 0.020 mm and are separated by 0.050 mm.When coherent monochromatic light passes through the slits the number of interference maxima within the central diffraction maximum:

The shimmering or wavy lines that can often be seen near the ground on a hot day are due to:

In a double-slit diffraction experiment the number of interference fringes within the central diffraction maximum can be increased by:

Two nearly equal wavelengths of light are incident on an N slit grating.The two wavelengths are not resolvable.When N is increased they become resolvable.This is because:

Two stars that are close together are photographed through a telescope.The black and white film is equally sensitive to all colors.Which situation would result in the most clearly separated images of the stars?

A diffraction pattern is produced on a viewing screen by illuminating a long narrow slit with light of wavelength λ\lambdaλ .If λ\lambdaλ is increased and no other changes are made:

In the equation d sin θ\thetaθ = m λ\lambdaλ for the lines of a diffraction grating, d is:

Diffraction plays an important role in which of the following phenomena?

Light of wavelength λ\lambdaλ is normally incident on a diffraction grating G.On the screen S, the central line is at P and the first order line is at Q, as shown.The distance between adjacent slits in the grating is:

As more slits with the same spacing are added to a multiple-slit system the lines:

A light spectrum is formed on a screen using a diffraction grating.The entire apparatus (source, grating and screen)is now immersed in a liquid of index 1.33.As a result, the pattern on the screen:

The intensity of the single-slit diffraction pattern at any angle θ is given by .For light of wavelength 480 nm falling on a slit of width 3.5 µm, what is the value of α when θ = 18°?

When a highly coherent beam of light is directed against a very fine wire, the shadow formed behind it is not just that of a single wire but rather looks like the shadow of several parallel wires.The explanation of this involves:

Monochromatic light is normally incident on a diffraction grating that is 1 cm wide and has 10,000 slits.The first order line is deviated at a 30° angle.What is the wavelength of the incident light?

Monochromatic light is normally incident on a diffraction grating.The mth order line is at an angle of diffraction θ\thetaθ and has width w.A wide single slit is now placed in front of the grating and its width is then slowly reduced.As a result:

Measurement

Motion Along a Straight Line

Vectors

Motion in Two and Three Dimensions

Force and Motion

Force and Motion

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves

Waves

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Coulombs Law

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference 1

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

In the equation sin $\theta$ = $\lambda$ /a for single-slit diffraction, $\theta$ is:

A diffraction pattern is produced on a viewing screen by illuminating a long narrow slit with light of wavelength $\lambda$ .If $\lambda$ is increased and no other changes are made:

In the equation d sin $\theta$ = m $\lambda$ for the lines of a diffraction grating, d is:

Monochromatic light is normally incident on a diffraction grating.The m^th order line is at an angle of diffraction $\theta$ and has width w.A wide single slit is now placed in front of the grating and its width is then slowly reduced.As a result: