Chapter 24 Part Two, pyh

53. Helium neon laser light ( = 632.8 nm) is sent through a single slit of width 0.30 mm. What is the width of the central maximum on a screen 1.0 m in back of the slit? (1 nm = 109 m) a. 2.0 mm b. 3.1 mm c. 4.2 mm d. 5.3 mm

C

69. The intensity of unpolarized light passing through a single sheet of polarizing material changes by a factor of: a. 1. b. 0.5. c. cos . d. cos2 .

B

74. The Michelson interferometer can make precise length measurements using which of the following phenomena? a. force b. interference c. magnification d. resolving power

B

81. A beam of plane polarized light is incident on 3 polarizers, the first with an axis at 30° to the original plane of polarization, the second at 60° to the original plane of polarization, and the third at 90° to the original plane of polarization. What angle does the plane of polarization of the transmitted light make with the original plane of polarization of the original beam? a. 30° b. 90° c. 180° d. The answer is not given.

B

77. Unpolarized light is passed through polarizer 1. The light then goes though polarizer 2 with its plane of polarization at 45.0° to that of polarizer 1. What fraction of the intensity of the original light gets though the second polarizer? a. 0.707 b. 0.500 c. 0.250 d. 0.125

C

56. The Yerkes refracting telescope has a 1-m diameter objective lens of focal length 20 m and an eyepiece of focal length 2.5 cm. What is the magnification of the planet Mars as seen through this telescope? a. 200 b. 400 c. 800 d. 1 000

C

58. An astronomical telescope has an objective lens with focal length fo and has an eyepiece with focal length fe. A second telescope has objective and eyepiece lenses with double the focal length of the first telescope. Which telescope gives the greater magnification and by what factor? a. The first telescope gives 4 times the magnification of the second. b. The second telescope gives 4 times the magnification of the first. c. Both telescopes give the same magnification. d. The actual focal lengths must be known to answer this question.

C

60. What is the resolving power of a diffraction grating that is capable of just distinguishing between two wavelengths of 568.50 nm and 569.60 nm? (1 nm = 109 m) a. 1.10 b. 517 c. 569 d. 1 035

B

62. A beam of unpolarized light in air strikes a flat piece of glass at an angle of incidence of 54.2°. If the reflected beam is completely polarized, what is the index of refraction of the glass? a. 1.60 b. 1.39 c. 1.52 d. 2.48

B

41. Upon reflection, light undergoes a 180° phase change: a. always. b. if the incident medium has the higher index of refraction. c. if the incident medium has the lower index of refraction. d. whenever the incident angle is less than the critical angle.

C

42. A soap bubble (n = 1.35) is floating in air. If the thickness of the bubble wall is 300 nm, which of the following wavelengths of visible light is strongly reflected? a. 620 nm (red) b. 580 nm (yellow) c. 540 nm (green) d. 500 nm (blue)

C

44. A possible means for making an airplane radar invisible is to coat the plane with an antireflective polymer. If radar waves have a wavelength of 4.8 cm, and the index of refraction of the polymer is n = 1.6, how thick would the coating be if a 180° phase change occurs at both surfaces? a. 32 mm b. 24 mm c. 7.5 mm d. 6.0 mm

C

52. If the objective lens of a compound microscope is replaced with a lens of double the focal length while the eyepiece also has its focal length doubled, what will happen to the overall magnification of the microscope? a. This will result in no change in the magnification. b. The magnification doubles. c. The magnification quadruples. d. The magnification decreases.

D

54. In the straight-ahead direction (θ = 0°) in Fraunhofer diffraction, which of the following is observed on the screen? a. a minimum equal in width to the adjacent minima b. a minimum double in width to the adjacent minima c. a maximum equal in width to the adjacent maxima d. a maximum double in width to the adjacent maxima

D

56. A diffraction grating with 10 000 lines/cm will exhibit the first order maximum for light of wavelength 510 nm at what angle? (1 nm = 109 m) a. 0.51° b. 0.62° c. 15.3° d. 31°

D

57. The Palomar reflecting telescope has a parabolic mirror with an 80 m focal length. What is the magnification achieved when an eyepiece of focal length 2.5 cm is used? a. 800 b. 1 200 c. 1 600 d. 3 200

D

59. A wavelength of 573 nm yields a first order maximum at 35° with a grating. At what angle will the second order maximum appear for this wavelength? a. 17.5° b. -35° c. 70° d. No second order maximum exists in this case.

D

34. 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

A

45. A hair is placed at one edge between two flat glass plates. When this arrangement is illuminated with yellow light of wavelength ( = 600 nm), a total of 121 dark bands are counted starting at the point of contact between the plates. How thick is the hair? (1 nm = 109 m) a. 3.6 105 m b. 1.8 105 m c. 3.6 104 m d. 1.8 104 m

A

49. A Fraunhofer diffraction pattern is created by monochromatic light shining through which of the following? a. single slit b. double slit c. triple slit d. more than 3 slits

A

57. What is the highest order maximum for wavelength 450 nm that can be obtained with a grating with 600 lines per mm? a. 3 b. 4 c. 6 d. 7

A

59. Light with a wavelength of 450 nm shines through a lens with an aperture diameter of 0.60 cm. Use Rayleigh's criterion to determine the limiting angle of resolution. (1 nm = 109 m) a. 9.2 105 rad b. 3.0 109 rad c. 1.3 104 rad d. 5.0 107 rad

A

66. The pupil of a cat's eye narrows to a slit of width 0.5 mm in daylight. Assuming a wavelength of 500 nm, what is the angular resolution? (1 nm = 109 m) a. 103 rad b. 5 103 rad c. 104 rad d. 5 104 rad

A

67. At what angle is the sun above the horizon if its light is found to be completely polarized when it is reflected from the top surface of a slab of glass (n = 1.65)? a. 31.2° b. 44.4° c. 58.8° d. 66.6°

A

70. What must be the resolving power of a grating allowing a spectral line at 601.10 nm to be distinguished from another line differing by 0.38 nm? (1 nm = 109 m) a. 1 600 b. 600 c. 300 d. 230

A

76. The critical angle for sapphire surrounded by air is 34.4°. Calculate the polarizing angle for sapphire. a. 60.5° b. 59.7° c. 58.6° d. 56.3°

A

39. 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° change of phase. d. the light that is not reflected has a 180° change of phase.

B

60. A diffraction grating has 4000 lines/cm. What is the slit separation? a. 4.0 μm b. 2.5 μm c. 400 nm d. 250 nm

B

40. 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.

B

46. A lens with focal length 5.0 cm is used as a magnifying glass. To obtain maximum magnification, how far in front of the lens should the object be placed? a. 5.0 cm b. 4.2 cm c. 10 cm d. 25 cm

B

47. Two thin layers of material with different indices of refraction are coated on a glass plate. The outer first material has n1 = 1.404, the inner second material has n2 = 1.531, and the glass has nglass = 1.62. If light is incident from air on the first layer, what is the phase change for light that reflects from the glass? a. 0° b. 180° c. 360° d. 540°

B

48. A surface is coated with a material having index of refraction 1.50. If light in air has a wavelength of 450 nm and is normally incident on this surface, and it is found through interference effects with this light that the surface is 10 wavelengths thick, which of the following is the thickness of the surface? a. 1.5 μm b. 3.0 μm c. 4.5 μm d. 6.8 μm

B

50. Light of wavelength 540 nm is incident on a slit of width 0.150 mm, and a diffraction pattern is produced on a screen that is 2.00 m from the slit. What is the width of the central bright fringe? (1 nm = 109 m) a. 0.720 cm b. 1.44 cm c. 1.76 cm d. 2.16 cm

B

50. Tripling the focal length of the objective lens of a compound microscope will change the magnification by what factor? a. 1/9 b. 1/3 c. 3 d. 9

B

51. A compound microscope has an eyepiece that: a. uses a real image from the objective as the object and forms its own real image. b. uses a real image from the objective as the object and forms a virtual image. c. uses a virtual image from the objective as the object and forms its own real image. d. uses a virtual image from the objective as the object and forms its own virtual image.

B

51. Light of wavelength 610 nm is incident on a slit of width 0.20 mm, and a diffraction pattern is produced on a screen that is 1.5 m from the slit. What is the distance of the second dark fringe from the center of the bright fringe? (1 nm = 109 m) a. 0.68 cm b. 0.92 cm c. 1.2 cm d. 1.4 cm

B

52. A Fraunhofer diffraction pattern is produced from a light source of wavelength 580 nm. The light goes through a single slit and onto a screen 1.0 m away. The first dark fringe is 5.0 mm from the central bright fringe. What is the slit width? (1 nm = 109 m) a. 0.24 mm b. 0.12 mm c. 0.10 mm d. 0.081 mm

B

53. A telescope has an objective lens with a focal length of 100 cm and an eyepiece of focal length 3.0 cm. What is the angular magnification of the telescope? a. 30 b. 33 c. 60 d. 180

B

58. At what angle will the highest order maximum appear for a wavelength 450 nm using a grating with 600 lines per mm? a. 36° b. 54° c. 81° d. 90°

B

64. A beam of polarized light of intensity I0 passes through a sheet of ideal polarizing material. The polarization axis of the beam and the transmission axis of the sheet differ by 30°. What is the intensity of the emerging light? a. 0.87 I0 b. 0.75 I0 c. 0.50 I0 d. 0.25 I0

B

65. What resolving power must a diffraction grating have in order to distinguish wavelengths of 590.10 nm and 591.70 nm? (1 nm = 109 m) a. 295 b. 369 c. 590.9 d. 739

B

68. Polaroid sunglasses help when skiing on snow on a sunny day by reducing the sunlight from the snow. This light from the snow has been polarized by: a. selective absorption. b. reflection. c. double refraction. d. scattering.

B

70. Unpolarized light of intensity I0 passes through two sheets of ideal polarizing material. If the transmitted intensity is 0.25 I0, what is the angle between the polarizer and the analyzer? a. 60° b. 45° c. 30° d. 22.5°

B

71. How many lines in a grating must be illuminated to obtain a resolving power of 900 in a third-order spectrum? a. 2 700 b. 300 c. 100 d. 903

B

73. The Michelson interferometer is a device that may be used to measure: a. magnifying power of lenses. b. light wavelength. c. atomic masses. d. electron charge.

B

When using 529-nm light, how far is the adjustable mirror of a Michelson interferometer moved when 300 fringe shifts are counted? a. 9.90 × 10-6 m b. 3.97 × 10-5 m c. 7.92 × 10-5 m d. 1.58 × 10-4 m

B

32. 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 = 109 m) a. 409 nm b. 492 nm c. 522 nm d. 638 nm

C

33. 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 = 109 m) a. 81 nm b. 163 nm c. 325 nm d. 488 nm

C

36. 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 = 109 m) a. 2.7 106 m b. 3.4 106 m c. 4.9 106 m d. 5.8 106 m

C

37. 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.

C

38. 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° as they are reflected. c. one beam changes phase by 180° when it is reflected. d. both waves have a trough.

C

54. Even relatively small astronomical telescopes are ordinarily not used for terrestrial observation because: a. their images are too bright. b. their images are too dim. c. their images are inverted. d. their images are not in color.

C

55. A multiple slit diffraction grating has a slit separation of 2.00 106 m. Find the wavelength of the monochromatic light that will have its second order bright fringe diffracted through an angle of 38.0°. (1 nm = 109 m) a. 120 nm b. 500 nm c. 616 nm d. 687 nm

C

55. A refracting astronomical telescope has objective and eyepiece lenses of focal lengths 20.0 cm and 0.40 cm, respectively. What is the angular magnification of this instrument? a. 19.6 b. 27 c. 50 d. 94

C

61. At what angle will the second order maximum occur for a wavelength of 400 nm using a diffraction grating with 10 000 lines per cm? a. 15.5° b. 24° c. 53° d. No second order maximum will occur in this case.

C

62. A microscope has an objective lens with an aperture of diameter 0.60 cm where a monochromatic light source of wavelength 580 nm is used to illuminate the object. It is determined that the minimum angle of resolution is 1.18 104 rad. If the illuminating source were replaced by an violet source of wavelength 420 nm, what would the minimum angle of resolution now become? (1 nm = 109 m) a. 1.6 104 rad b. 1.2 104 rad c. 0.85 104 rad d. 0.58 104 rad

C

63. Polarization of light can be achieved using a dichroic material like Polaroid by which of the following processes? a. reflection b. double refraction c. selective absorption d. scattering

C

64. If different filters are used with an astronomical telescope, which of the following would give the best resolution? a. red b. green c. blue d. All yield the same resolution.

C

68. A binary star system in the constellation Orion has an angular separation between the stars of 105 radians. Assuming a wavelength of 500 nm, what is the smallest aperture (diameter) telescope that will just resolve the two stars? (1 nm = 109 m) a. 3.0 cm b. 4.2 cm c. 6.1 cm d. 12.6 cm

C

72. Which of the following primarily determines the resolution of a telescope? a. the barrel length b. the focal length of the objective c. the diameter of the objective d. the diameter of the eyepiece

C

74. Sunlight reflected from a smooth ice surface is completely polarized. Determine the angle of incidence. (nice = 1.309) a. 25.60° b. 47.89° c. 52.62° d. 56.26°

C

75. If the polarizing angle for diamond is 67.5°, what is the index of refraction of this material? a. 2.00 b. 2.20 c. 2.41 d. 2.65

C

76. A fringe shift occurs for every ______ wavelength movement of the adjustable mirror in a Michelson interferometer. a. whole b. half c. quarter d. eighth

C

80. LCD stands for: a. linearly collimated diffraction. b. longitudinally combined depolarization. c. liquid crystal display. d. lighted compact disk.

C

31. 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 = 109 m) a. 400 nm b. 492 nm c. 624 nm d. 580 nm

D

35. Two flat glass plates are in contact along one end and are separated by a sheet of paper 4.0 106 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 = 109 m) a. 7 b. 9 c. 13 d. 17

D

46. Newton's rings: a. are a sound that light can cause. b. require oil to occur. c. are a result of Fraunhofer diffraction. d. are an interference phenomenon.

D

47. A lens is used as a magnifier. Which of the following statements is incorrect? a. The lens is convex. b. The dioptric power of the lens is positive. c. The magnification is greatest when the eye focuses at the near point. d. The focal length of the lens must be negative.

D

48. What is the approximate magnification of a compound microscope with objective and eyepiece focal lengths of 0.30 cm and 3.6 cm, respectively, and a separation between lenses of 20 cm? a. 12 b. 20 c. 67 d. 460

D

49. You are building a compound microscope with an objective lens of focal length 0.70 cm and an eyepiece lens of focal length 5.0 cm. You mount the lenses 18 cm apart. What is the maximum magnification of your microscope? a. 3.1 b. 7.3 c. 67 d. 130

D

61. A microscope has an objective lens with an aperture diameter 0.60 cm. A monochromatic light source of wavelength 580 nm is used to illuminate the object. It is determined that the minimum angle of resolution is 1.18 104 rad. If the present lens were replaced by one with an aperture of diameter 0.90 cm, what would the minimum angle of resolution now become? (1 nm = 109 m) a.1.5 104 rad b.1.8 104 rad c. 0.88 104 rad d. 0.79 104 rad

D

63. An individual's eye pupil changes from a diameter of 3.5 mm to 1.5 mm as the illumination is increased. By what factor does the minimum angle of resolution change? a. 0.43 b. 0.65 c. 2.0 d. 2.3

D

65. When the sun is located near one of the horizons, an observer looking at the sky directly overhead will view partially polarized light. This effect is due to which of the following processes? a. reflection b. double refraction c. selective absorption d. scattering

D

66. An unpolarized beam of light is incident on a pane of glass (n = 1.56) such that the reflected component coming off the glass is completely polarized. What is the angle of incidence in this case? a. 32.7° b. 41.0° c. 49.0° d. 57.3°

D

67. The 2.4-m diameter Hubble space telescope has been placed into Earth orbit by the space shuttle. Assuming a wavelength of 500 nm, what angular resolution could this telescope achieve by Rayleigh's criterion? (1 nm = 109 m) a. 7.5 106 rad b. 5.7 106 rad c. 3.6 106 rad d. 2.5 107 rad

D

69. Find the radius of a star image formed on the retina of the eye if the aperture diameter (the pupil) at night is 0.70 cm and the length of the eye is 3.0 cm. Assume the wavelength of starlight in the eye is 500 nm. (1 nm = 109 m) a. 2.6 104 m b. 5.2 104 m c. 3.1 105 m d. 2.6 106 m

D

71. The blue light from the sky has been polarized by: a. selective absorption. b. reflection. c. double refraction. d. scattering.

D

72. A material is optically active if it: a. absorbs light passing through it. b. transmits all light passing through it. c. exhibits interference. d. rotates the plane of polarization of the light passing through it

D

73. How far above the horizon is the moon when its image reflected in calm water is completely polarized? (nwater = 1.333) a. 53.12° b. 18.44° c. 22.20° d. 36.88°

D

78. Unpolarized light is passed through polarizer 1. The light then goes though polarizer 2 with its plane of polarization at 45.0° to that of polarizer 1. Polarizer 3 is placed after polarizer 2. Polarizer 3 has its plane of polarization at 45° to the plane of polarization of polarizer 2 and at 90° to that of polarizer 1. What fraction of the intensity of the original light gets though the last polarizer? a. 0.707 b. 0.500 c. 0.250 d. 0.125

D

79. Plane polarized light is sent through two consecutive polarizers, the first having its plane of polarization in the same direction as the incident light and the second having its plane at 90° to the original plane of polarization. A third polarizer, with plane of polarization at 30° to the original plane of polarization, is placed between the two other polarizers. What fraction of the original intensity now gets through? a. 0 b. 0.56 c. 0.25 d. 0.19

D