Question 1

If the central maximum in a single slit diffraction pattern has intensity I0,the intensity of the secondary maximum that is nearest to it is closest to

Accepted Answer

A)   0.045I0.
B)   I0/4.
C)   I0/2.
D)   I0.
E)   2I0. A

Question 2

A slit of width 0.010 mm has light of frequency 5.0 × 1014 Hz passing through it onto a screen 60 cm away.How wide is the central maximum? (c = 3.00 × 108 m/s)

Accepted Answer

A)   0.12 cm
B)   7.2 cm
C)   1.8 cm
D)   3.6 cm
E)   0.90 cm B

Question 3

When monochromatic light illuminates a grating with 7000 lines per centimeter,its second order maximum is at 62.4°.What is the wavelength of the light?

Accepted Answer

A)   336 nm
B)   363 nm
C)   452 nm
D)   633 nm
E)   752 nm D

Question 4

A single slit forms a diffraction pattern,with the first minimum at an angle of 40.0° from central maximum,using monochromatic light of 490-nm wavelength.What is the width of the slit?

Accepted Answer

A)   762 nm
B)   731 nm
C)   700 nm
D)   668 nm
E)   637 nm

Question 5

A single slit illuminated with a 500 nm light gives a diffraction pattern on a far screen.The 5th minimum occurs at 7.00° away from the central maximum.At what angle does the 18th minimum occur?

Accepted Answer

A)   26.0°
B)   1.94°
C)   5.05°
D)   0.44°

Question 6

A single slit forms a diffraction pattern,with the first minimum at an angle of 40.0° from central maximum,when monochromatic light of 630-nm wavelength is used.The same slit,illuminated by a new monochromatic light source,produces a diffraction pattern with the second minimum at a 60.0° angle from the central maximum.What is the wavelength of this new light?

Accepted Answer

A)   425 nm
B)   450 nm
C)   475 nm
D)   500 nm
E)   525 nm

Question 7

A researcher is investigating a cubic crystal with X-rays.He is looking at Bragg reflection from the planes parallel to the cube faces.He finds that when using X-rays of 0.165 nm a strong first maximum occurs when the beam makes an angle of 23.5° with the planes.What is the spacing of adjacent atoms in the crystal?

Accepted Answer

The answer of A researcher is investigating a cubic crystal...

Question 8

A camera used for aerial surveillance has a lens with a 30-cm maximum aperture and a 42-cm focal length.Assume light of 550-nm wavelength is used and that the resolution of the camera is limited solely by diffraction.What is the angular resolution of the camera at maximum aperture?

Accepted Answer

A)   1.6 µrad
B)   2.2 µrad
C)   3.2 µrad
D)   4.5 µrad
E)   6.3 µrad

Question 9

A radio telescope 200 m in diameter is used to investigate sources emitting a 21-cm wavelength wave.What is the minimum angular separation of the sources that can be resolved by this system?

Accepted Answer

A)   0.073°
B)   0.030°
C)   0.0013°
D)   0.154°
E)   0.0026°

Question 10

A single slit forms a diffraction pattern with monochromatic light.The 4th minimum of the pattern occurs at an angle of 35° from the central maximum.How many bright bands are on each side of the central maximum?

Accepted Answer

A)   5
B)   4
C)   6
D)   7
E)   8

Question 11

A 10-inch telescope (25.4 cm in diameter)is used to determine if what appears to be one star is actually two stars.Stars are so far away that they are essentially point sources.How close (in angle)can the two stars be and still be resolved by this telescope if it is focusing light of wavelength of 550 nm? (Consider only the limitation due to diffraction.)

Accepted Answer

A)   4.2 × 10-8 degree
B)   2.6 × 10-6 degree
C)   3.0 × 10-4 degree
D)   1.5 × 10-4 degree
E)   6.6 × 10-8 degree

Question 12

What is the limiting angle of resolution for the eye if the pupil diameter of the eye is 4.0 mm,the wavelength of the light is 600 nm,and index of refraction of the liquid in the eye is 1.34?

Accepted Answer

A)   0.42 mrad
B)   0.21 mrad
C)   0.14 mrad
D)   0.11 mrad
E)   0.26 mrad

Question 13

If an X-ray beam of wavelength 1.4 × 10-10 m makes an angle of 20° with a set of planes in a crystal causing first order constructive interference,at what angle will the second order line appear?

Accepted Answer

A)   40°
B)   20°
C)   43°
D)   4.0°
E)   11°

Question 14

Certain planes of a crystal of halite have a spacing of 0.399 nm.The crystal is irradiated by a beam of X-rays.First order constructive interference occurs when the beam makes an angle of 20° with the planes.What is the wavelength of the X-rays?

Accepted Answer

A)   0.14 nm
B)   0.17 nm
C)   0.21 nm
D)   0.24 nm
E)   0.27 nm

Question 15

Light of wavelength 687 nm is incident on a single slit 0.75 mm wide.At what distance from the slit should a screen be placed if the second dark fringe in the diffraction pattern is to be 1.7 mm from the center of the diffraction pattern?

Accepted Answer

A)   0.39 m
B)   0.47 m
C)   0.93 m
D)   1.1 m
E)   1.9 m

Question 16

If the fifth order minimum in the diffraction pattern due to a thin slit is at 40° from the central maximum,at what angle does the first order minimum occur?

Accepted Answer

A)   8.0°
B)   3.4°
C)   4.0°
D)   7.4°
E)   1.7°

Question 17

What is the angular separation of the two second-order spectral lines having wavelengths  and  using a diffraction grating having 456 lines/mm?

Accepted Answer

A)   1.63°
B)   1.52°
C)   0.815°
D)   3.26°

Question 18

A diffraction grating has rulings of 890 lines/mm.When white light is incident normally on the grating,what is the longest wavelength that forms an intensity maximum in the fifth order?

Accepted Answer

A)   225 nm
B)   200 nm
C)   250 nm
D)   275 nm
E)   300 nm

Question 19

Light of wavelength 633 nm from a He-Ne laser passes through a circular aperture and is observed on a screen 4.0 m behind the aperture.The diameter of the central bright area is 5.4 cm.What is the diameter of the aperture?

Accepted Answer

A)   110 μm
B)   2.0 μm
C)   6600 μm
D)   960 μm

Question 20

A certain astronomical telescope has a diameter of 5.60 m.Considering only the limitation due to diffraction,what is the minimum angle of resolution for this telescope at a wavelength of 620 nm?

Accepted Answer

A)   0.111 µrad
B)   0.311 µrad
C)   0.270 µrad
D)   0.135 µrad
E)   0.405 µrad

Exam 36: Diffraction

If the central maximum in a single slit diffraction pattern has intensity I₀,the intensity of the secondary maximum that is nearest to it is closest to

A slit of width 0.010 mm has light of frequency 5.0 × 10¹⁴ Hz passing through it onto a screen 60 cm away.How wide is the central maximum? (c = 3.00 × 10⁸ m/s)