Question 1

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)   becomes narrower
E)   do not change in position or widthF) C) and E)
G) B) and E)

Question 2

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 givenF) C) and D)
G) A) and C)

Question 3

Radio waves are readily diffracted around buildings whereas light waves are negligibly diffracted around buildings. This is because radio waves:

Accepted Answer

A)   are plane polarized
B)   have much longer wavelengths than light waves
C)   have much shorter wavelengths than light waves
D)   are nearly monochromatic (single frequency) 
E)   are amplitude modulated (AM) F) A) and D)
G) B) and C)

Question 4

A diffraction pattern is produced on a viewing screen by illuminating a long narrow slit with light of wavelength  λ\lambdaλ . If the slit width is decreased 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 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 F) C) and D)
G) All of the above

Question 5

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)   VF) B) and C)
G) A) and D)

Question 6

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 blueF) B) and D)
G) B) and E)

Question 7

A diffraction grating just resolves the wavelengths 400.0 nm and 400.1 nm in first order. The number of slits in the grating is:

Accepted Answer

A)   400
B)   1000
C)   2500
D)   4000
E)   not enough information is givenF) A) and D)
G) C) and E)

Question 8

In the equation d sin θ	hetaθ = m λ\lambdaλ for the lines of a diffratction grating m 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 F) C) and D)
G) A) and E)

Question 9

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 effectF) B) and D)
G) A) and C)

Question 10

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 narrowF) A) and B)
G) All of the above

Question 11

In order to obtain a good single-slit diffraction pattern, the slit width could be:

Accepted Answer

A)    λ\lambdaλ 
B)    λ\lambdaλ /10
C)   10 λ\lambdaλ 
D)   104 λ\lambdaλ 
E)    λ\lambdaλ /104 F) A) and B)
G) C) and D)

Question 12

X rays are:

Accepted Answer

A)   electromagnetic waves
B)   negatively charged ions
C)   rapidly moving electrons
D)   rapidly moving protons
E)   rapidly moving neutronsF) None of the above
G) B) and E)

Question 13

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:

Accepted Answer

A)   3 λ\lambdaλ /5
B)   3 λ\lambdaλ /4
C)   4 λ\lambdaλ /5
D)   5 λ\lambdaλ /4
E)   5 λ\lambdaλ /3 F) A) and B)
G) A) and C)

Question 14

In the equation  ϕ\phiϕ  = (2  π\piπ a/ λ\lambdaλ )  sin  θ	hetaθ for single-slit diffraction,  ϕ\phiϕ  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  π\piπ  where N is an integer
E)   (N + 1/2)   π\piπ  where N is an integer F) None of the above
G) A) and D)

Question 15

For a certain multiple-slit barrier the slit separation is 4 times the slit width. For this system:

Accepted Answer

A)   the orders of the lines that appear are all multiples of 4
B)   the orders of lines that appear are all multiples of 2
C)   the orders of the missing lines are all multiples of 4
D)   the orders of the missing lines are all multiples of 2
E)   none of the above are trueF) A) and E)
G) C) and E)

Question 16

A mixture of 450-nm and 900-nm light is incident on a multiple-slit system. Which of the following is true?

Accepted Answer

A)   All lines of the 900-nm light coincide with lines of the 450-nm light
B)   All lines of the 450-nm light coincide with lines of the 900-nm light
C)   All lines of the 800-nm light coincide with lines of the 450-nm light
D)   None of the lines of the 450-nm light coincide with lines of the 900-nm light
E)   All of the lines of the 450-nm light coincide with lines of the 900-nm lightF) D) and E)
G) A) and B)

Question 17

Monochromatic light is normally incident on a diffraction grating. The mth order line is at a angle of diffraction angle  θ	hetaθ 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  θ	hetaθ and w increase
B)   both  θ	hetaθ and w decrease
C)    θ	hetaθ remains the same and w increases
D)    θ	hetaθ remains the same and w decreases
E)    θ	hetaθ decreases and w increases F) D) and E)
G) A) and D)

Question 18

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 theseF) A) and E)
G) None of the above

Question 19

In the equation d sin θ	hetaθ  = m λ\lambdaλ  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 F) A) and D)
G) A) and B)

Question 20

In a single-slit diffraction pattern, the central maximum is about twice as wide as the other maxima. This is because:

Accepted Answer

A)   half the light is diffracted up and half is diffracted down
B)   the central maximum has both electric and magnetic fields present
C)   the small angle approximation applies only near the central maximum
D)   the screen is flat instead of spherical
E)   none of the aboveF) None of the above
G) B) and E)

Exam 36: Diffraction

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:

Correct Answer
verified

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

Correct Answer
verified

In order to obtain a good single-slit diffraction pattern, the slit width could be:

Correct Answer
verified

A mixture of 450-nm and 900-nm light is incident on a multiple-slit system. Which of the following is true?

Correct Answer
verified

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

Correct Answer
verified

In a single-slit diffraction pattern, the central maximum is about twice as wide as the other maxima. This is because:

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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:

Correct Answer
verified

A diffraction grating just resolves the wavelengths 400.0 nm and 400.1 nm in first order. The number of slits in the grating is:

Correct Answer
verified

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:

Correct Answer
verified

Monochromatic light is normally incident on a diffraction grating. The m^th order line is at a angle of diffraction angle $\theta$ 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:

Correct Answer
verified

For a certain multiple-slit barrier the slit separation is 4 times the slit width. For this system:

Correct Answer
verified

X rays are:

Correct Answer
verified

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?

Correct Answer
verified

Correct Answer
verified

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:

Correct Answer
verified

Radio waves are readily diffracted around buildings whereas light waves are negligibly diffracted around buildings. This is because radio waves:

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

Exam 36: Diffraction

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:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

In order to obtain a good single-slit diffraction pattern, the slit width could be:

Correct AnswerverifiedShow Answer

A mixture of 450-nm and 900-nm light is incident on a multiple-slit system. Which of the following is true?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

In a single-slit diffraction pattern, the central maximum is about twice as wide as the other maxima. This is because:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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:

Correct AnswerverifiedShow Answer

A diffraction grating just resolves the wavelengths 400.0 nm and 400.1 nm in first order. The number of slits in the grating is:

Correct AnswerverifiedShow Answer

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:

Correct AnswerverifiedShow Answer

Monochromatic light is normally incident on a diffraction grating. The mth order line is at a angle of diffraction angle 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:

Correct AnswerverifiedShow Answer

For a certain multiple-slit barrier the slit separation is 4 times the slit width. For this system:

Correct AnswerverifiedShow Answer

X rays are:

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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:

Correct AnswerverifiedShow Answer

Radio waves are readily diffracted around buildings whereas light waves are negligibly diffracted around buildings. This is because radio waves:

Correct AnswerverifiedShow Answer

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:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Monochromatic light is normally incident on a diffraction grating. The m^th order line is at a angle of diffraction angle $\theta$ 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:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified