Question 1

The widths of the lines produced by monochromatic light falling on a diffraction grating can be reduced by:

Accepted Answer

A)  increasing the wavelength of the light 
B)  increasing the number of rulings without changing their spacing 
C)  decreasing the spacing between adjacent rulings without changing the number of rulings 
D)  decreasing both the wavelength and the spacing between rulings by the same factor 
E)  increasing the number of rulings and decreasing their spacing so the length of the grating remains the same 
A)  increasing the wavelength of the light 
B)  increasing the number of rulings without changing their spacing 
C)  decreasing the spacing between adjacent rulings without changing the number of rulings 
D)  decreasing both the wavelength and the spacing between rulings by the same factor 
E)  increasing the number of rulings and decreasing their spacing so the length of the grating remains the same

Question 2

In the equation $\phi$ = (2$\pi$a/$\lambda$) sin $\theta$for single-slit diffraction, $\phi$ 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

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 4

In the equation d sin$\theta$ = m$\lambda$for the lines of a diffratction 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 5

If white light is incident on a diffraction grating:

Accepted Answer

A)  the first order lines for all visible wavelengths occur at smaller diffraction angles than any of the second order lines 
B)  some first order lines overlap the second order lines if the ruling separation is small but do not if it is large 
C)  some first order lines overlap second order lines if the ruling separation is large but do not if it is small 
D)  some first order lines overlap second order lines no matter what the ruling separation 
E)  first and second order lines have the same range of diffraction angles 
A)  the first order lines for all visible wavelengths occur at smaller diffraction angles than any of the second order lines 
B)  some first order lines overlap the second order lines if the ruling separation is small but do not if it is large 
C)  some first order lines overlap second order lines if the ruling separation is large but do not if it is small 
D)  some first order lines overlap second order lines no matter what the ruling separation 
E)  first and second order lines have the same range of diffraction angles

Question 6

When the atmosphere is not quite clear, one may sometimes see colored circles concentric with the Sun or the Moon. These are generally not more than a few diameters of the Sun or Moon and invariably the innermost ring is blue. The explanation for this phenomena involves:

Accepted Answer

A)  reflection 
B)  refraction 
C)  interference 
D)  diffraction 
E)  Doppler effect 
A)  reflection 
B)  refraction 
C)  interference 
D)  diffraction 
E)  Doppler effect

Question 7

Monochromatic plane waves of light are incident normally on a single slit. Which one of the five figures below correctly shows the diffraction pattern observed on a distant screen?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 8

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 9

The dispersion of a diffraction grating indicates:

Accepted Answer

A)  the resolution of the grating 
B)  the separation of lines of the same order 
C)  the number of rulings in the grating 
D)  the width of the lines 
E)  the separation of lines of different order for the same wavelength 
A)  the resolution of the grating 
B)  the separation of lines of the same order 
C)  the number of rulings in the grating 
D)  the width of the lines 
E)  the separation of lines of different order for the same wavelength

Question 10

When 450-nm light is incident normally on a certain double-slit system the number of interference maxima within the central diffraction maximum is 5. When 900-nm light is incident on the same slit system the number is:

Accepted Answer

A)  2 
B)  3 
C)  5 
D)  9 
E)  10 
A)  2 
B)  3 
C)  5 
D)  9 
E)  10

Question 11

An x-ray beam of wavelength 3 *10-11 m is incident on a calcite crystal of lattice spacing 0.3 nm. The smallest angle between crystal planes and the x-ray beam which will result in constructive interference is:

Accepted Answer

A)  2.87° 
B)  5.73° 
C)  11.63° 
D)  23.27° 
E)  none of these 
A)  2.87° 
B)  5.73° 
C)  11.63° 
D)  23.27° 
E)  none of these

Question 12

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 13

When light of a certain wavelength is incident normally on a certain diffraction grating the line of order 1 is at a diffraction angle of 25 $\degree$. The diffraction angle for the second order line is:

Accepted Answer

A)  25 $\degree$ 
B)  42 $\degree$ 
C)  50 $\degree$ 
D)  58 $\degree$ 
E)  75 $\degree$ 
A)  25 $\degree$ 
B)  42 $\degree$ 
C)  50 $\degree$ 
D)  58 $\degree$ 
E)  75 $\degree$

Question 14

The diagram shows a single slit with the direction to a point P on a distant screen shown. At P, the pattern has its second minimum (from its central maximum). If X and Y are the edges of the slit, what is the path length difference (PX) - (PY)?

Accepted Answer

A)  $\lambda$/2 
B)  $\lambda$ 
C)  3$\lambda$/2 
D)  2$\lambda$ 
E)  5$\lambda$/2 
A)  $\lambda$/2 
B)  $\lambda$ 
C)  3$\lambda$/2 
D)  2$\lambda$ 
E)  5$\lambda$/2

Question 15

Two wavelengths, 800 nm and 600 nm, are used separately in single-slit diffraction experiments. The diagram shows the intensities on a far-away viewing screen as function of the angle made by the rays with the straight-ahead direction. If both wavelengths are then used simultaneously, at which angle is the light on the screen purely 800-nm light?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E

Question 16

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 17

At the second minimum adjacent to the central maximum of a single-slit diffraction pattern the Huygens wavelet from the top of the slit is 180$\degree$ out of phase with the wavelet from:

Accepted Answer

A)  a point one-fourth of the slit width from the top 
B)  the midpoint of the slit 
C)  a point one-fourth of the slit width from the bottom of the slit 
D)  the bottom of the slit 
E)  none of these 
A)  a point one-fourth of the slit width from the top 
B)  the midpoint of the slit 
C)  a point one-fourth of the slit width from the bottom of the slit 
D)  the bottom of the slit 
E)  none of these

Question 18

The resolving power of a telescope can be increased by:

Accepted Answer

A)  increasing the objective focal length and decreasing the eyepiece focal length 
B)  increasing the lens diameters 
C)  decreasing the lens diameters 
D)  inserting a correction lens between objective and eyepiece 
E)  none of the above 
A)  increasing the objective focal length and decreasing the eyepiece focal length 
B)  increasing the lens diameters 
C)  decreasing the lens diameters 
D)  inserting a correction lens between objective and eyepiece 
E)  none of the above

Question 19

If we increase the wavelength of the light used to form a double-slit diffraction pattern:

Accepted Answer

A)  the width of the central diffraction peak increases and the number of bright fringes within the peak increases 
B)  the width of the central diffraction peak increases and the number of bright fringes with the peak decreases 
C)  the width of the central diffraction peak decreases and the number of bright fringes within the peak increases 
D)  the width of the central diffraction peak decreases and the number of bright fringes within the peak decreases 
E)  the width of the central diffraction peak increases and the number of bright fringes within the peak stays the same 
A)  the width of the central diffraction peak increases and the number of bright fringes within the peak increases 
B)  the width of the central diffraction peak increases and the number of bright fringes with the peak decreases 
C)  the width of the central diffraction peak decreases and the number of bright fringes within the peak increases 
D)  the width of the central diffraction peak decreases and the number of bright fringes within the peak decreases 
E)  the width of the central diffraction peak increases and the number of bright fringes within the peak stays the same

Question 20

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

Exam 36: Diffraction

The widths of the lines produced by monochromatic light falling on a diffraction grating can be reduced by:

In the equation ϕ\phiϕ = (2 π\piπ a/ λ\lambdaλ ) sin θ\thetaθ for single-slit diffraction, ϕ\phiϕ is:

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 diffratction grating d is:

If white light is incident on a diffraction grating:

When the atmosphere is not quite clear, one may sometimes see colored circles concentric with the Sun or the Moon. These are generally not more than a few diameters of the Sun or Moon and invariably the innermost ring is blue. The explanation for this phenomena involves:

Monochromatic plane waves of light are incident normally on a single slit. Which one of the five figures below correctly shows the diffraction pattern observed on a distant screen?

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

The dispersion of a diffraction grating indicates:

When 450-nm light is incident normally on a certain double-slit system the number of interference maxima within the central diffraction maximum is 5. When 900-nm light is incident on the same slit system the number is:

An x-ray beam of wavelength 3 *10-11 m is incident on a calcite crystal of lattice spacing 0.3 nm. The smallest angle between crystal planes and the x-ray beam which will result in constructive interference is:

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:

When light of a certain wavelength is incident normally on a certain diffraction grating the line of order 1 is at a diffraction angle of 25 °\degree° . The diffraction angle for the second order line is:

The diagram shows a single slit with the direction to a point P on a distant screen shown. At P, the pattern has its second minimum (from its central maximum). If X and Y are the edges of the slit, what is the path length difference (PX) - (PY)?

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:

At the second minimum adjacent to the central maximum of a single-slit diffraction pattern the Huygens wavelet from the top of the slit is 180 °\degree° out of phase with the wavelet from:

The resolving power of a telescope can be increased by:

If we increase the wavelength of the light used to form a double-slit diffraction pattern:

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

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

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 I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Electric Charge

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

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

In the equation $\phi$ = (2 $\pi$ a/ $\lambda$ ) sin $\theta$ for single-slit diffraction, $\phi$ 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 diffratction grating d is:

An x-ray beam of wavelength 3 *10^-¹¹ m is incident on a calcite crystal of lattice spacing 0.3 nm. The smallest angle between crystal planes and the x-ray beam which will result in constructive interference is:

When light of a certain wavelength is incident normally on a certain diffraction grating the line of order 1 is at a diffraction angle of 25 $\degree$ . The diffraction angle for the second order line is:

At the second minimum adjacent to the central maximum of a single-slit diffraction pattern the Huygens wavelet from the top of the slit is 180 $\degree$ out of phase with the wavelet from: