Physics

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

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

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

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

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

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

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

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

14. Waves from a radio station with a wavelength of 600 m arrive at a home receiver a distance 50 km away from the transmitter by two paths. One is a direct line path and the second by reflection from a mountain directly behind the receiver. What is the minimum distance between the mountain and receiver such that destructive interference occurs at the location of the listener? Assume no phase change on reflection. a. 150 m b. 300 m c. 450 m d. 600 m

A

16. After light from a source passes through two slits, a first order bright spot is seen on the wall at point P. Which distance is equal to the wavelength of the light? a. the extra distance one beam must travel b. the distance between beams as they leave the slit c. the distance of point P from the central point of the interference pattern d. the distance between slits

A

21. In a Young's experiment, the paths from the slits to a point on the screen differ in length, causing destructive interference at the point. Which of the following path difference would cause this destructive interference? a. 5λ/2 b. 3λ/4 c. 4λ d. None of the above.

A

30. What wavelength monochromatic source in the visible region (390 to 710 nm) can be used to constructively reflect off a soap film (n = 1.46) if the film is 240 nm thick? a. 467 nm b. 562 nm c. 587 nm d. 480 nm

A

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

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

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

6. In a Young's double-slit interference apparatus, by what factor is the distance between adjacent light and dark fringes changed when the separation between slits is doubled? a. 1/4 b. 1/2 c. 1 d. 2

B

. Two narrow slits are 0.025 mm apart. When a laser shines on them, bright fringes form on a screen that is a meter away. These fringes are 3.0 cm apart. What is the separation between the second order bright fringe and the central fringe? a. 8.6 cm b. 6.0 cm c. 5.3 cm d. 2.6 cm

B

11. A Young's double-slit apparatus is set up where a screen is positioned 0.80 m from the double slits. If the distance between alternating bright fringes is 0.95 cm, and the light source has a wavelength of 580 nm, what is the separation of the double slits? (1 nm = 109 m) a. 2.8 105 m b. 4.9 105 m c. 5.6 105 m d. 6.0 105 m

B

12. A Young's double-slit apparatus is set up. The source wavelength is 430 nm, and the double-slit spacing is 0.040 mm. At what distance from the double slits should the screen be placed if the spacing between alternating bright fringes is to be 2.4 cm? (1 nm = 109 m) a. 1.6 m b. 2.2 m c. 2.4 m d. 2.9 m

B

15. Two beams of coherent light are shining on the same piece of white paper. With respect to the crests and troughs of such waves, darkness will occur on the paper where: a. the crest from one wave overlaps with the crest from the other. b. the crest from one wave overlaps with the trough from the other. c. the troughs from both waves overlap. d. darkness cannot occur as the two waves are coherent.

B

18. A Young's interference experiment is conducted with blue green argon laser light ( = 515 nm). The separation between the slits is 0.50 mm, and the interference pattern appears on a screen 3.3 m away. What is the spacing between the bright fringes? (1 nm = 109 m) a. 1.7 mm b. 3.4 mm c. 5.1 mm d. 6.8 mm

B

23. In a Young's double-slit experiment, how many maxima occur between the 4th order maxima? a. 6 b. 7 c. 8 d. Three more than the number of minima.

B

25. What is the minimum thickness of a glycerin film (n = 1.47) on which light of wavelength 600 nm shines that results in constructive interference of the reflected light? Assume the film is surrounded front and back by air. a. 75 nm b. 102 nm c. 150 nm d. 204 nm

B

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

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

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

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

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

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

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

A Young's double-slit apparatus is set up so that a screen is positioned 1.6 m from the double slits, and the spacing between the two slits is 0.040 mm. What is the distance between alternating bright fringes on the screen if the light source has a wavelength of 630 nm? (1 nm = 109 m) a. 0.016 m b. 0.025 m c. 0.032 m d. 0.047 m

B

13. A light source simultaneously emits light of two wavelengths, 480 nm and 560 nm, respectively. The source is used in a double slit interference experiment where the slit spacing is a 0.040 mm, and the distance between double slits and the screen is 1.2 m. What is the separation between the second order bright fringes of the two wavelengths as they appear on the screen? (1 nm = 109 m) a. 0.16 cm

C

17. If the 2nd order fringe in Young's double-slit experiment occurs at an angle of 45.0°, what is the relationship between the wavelength and the distance between slits, d? a. d = 1.41 b. d = 2.00 c. d = 2.83 d. d = 4.00

C

19. That light can undergo interference is evidence that it: a. has electric properties. b. is made of corpuscles. c. behaves like a wave. d. has a phase of 180°.

C

20. In a Young's experiment, the paths from the slits to a point on the screen differ in length causing constructive interference at the point. Which of the following path difference would cause this constructive interference? a. 5λ/2 b. 3λ/4 c. 4λ d. None of the above.

C

22. Laser light sent through a double slit produces an interference patter on a screen 3.00 m from the slits. If the second order maximum occurs at an angle of 12.0°, at what angle does the eighth order maximum occur? a. No eighth order maximum occurs. b. 48.0° c. 56.3° d. Not enough information is given.

C

27. A silicon monoxide thin film (n = 1.45) of thickness 90.0 nm is applied to a camera lens made of glass (n = 1.55). This will result in a destructive interference for reflected light of what wavelength? a. 720 nm b. 558 nm c. 522 nm d. 450 nm

C

28. The dark spot observed in the center of a Newton's rings pattern is attributed to which of the following? a. polarization of light when reflected b. polarization of light when refracted c. phase shift of light when reflected d. phase shift of light when refracted

C

29. What wavelength monochromatic source in the visible region (390 to 710 nm) can be used to constructively reflect off a soap film (n = 1.46) if the film is 77 nm thick? a. 409 nm b. 430 nm c. 450 nm d. 558 nm

C

3. A Young's double slit has a slit separation of 2.50 105 m on which a monochromatic light beam is directed. The resultant bright fringes on a screen 1.00 m from the double slit are separated by 2.30 102 m. What is the wavelength of this beam? (1 nm = 109 m) a. 373 nm b. 454 nm c. 575 nm d. 667 nm

C

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

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

5. In order to produce a sustained interference pattern by light waves from multiple sources, which of the following conditions must be met? a. Sources are coherent. b. Sources are monochromatic. c. Both choices above are valid. d. None of the choices above are valid.

C

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

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

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

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

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

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

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

C

10. A Young's double-slit apparatus is set up. A screen is positioned 1.60 m from the double slits, and the spacing between the two slits is 0.040 0 mm. The distance between alternating bright fringes is 1.42 cm. What is the light source wavelength? (1 nm = 109 m) a. 710 nm b. 490 nm c. 280 nm d. 355 nm

D

24. The blue tint of a coated camera lens is largely caused by what effects? a. diffraction b. refraction c. polarization d. interference

D

26. Light of wavelength 500 nm shines on a soap bubble film (n = 1.46). For what soap film thickness, other than the minimum thickness, will constructive interference occur? a. 63 nm b. 86 nm c. 172 nm d. 257 nm

D

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

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

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

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

8. In a Young's double-slit interference apparatus, by what factor is the distance between adjacent light and dark fringes changed when the wavelength of the source is doubled? a. 1/4 b. 1/2 c. 1 d. 2

D

In a Young's double-slit interference apparatus, the distance from the slits to the screen is doubled. The distance between adjacent light and dark fringes changes by a factor of: a. ¼. b. ½. c. 1. d. 2.

D

2. If a wave from one slit of a Young's double-slit set up arrives at a point on the screen one wavelength behind the wave from the other slit, what is observed at that point? a. dark fringe b. bright fringe c. multi colored fringe d. gray fringe, neither dark nor bright

b

1. Interference effects observed in the early 1800s were instrumental in supporting a concept of the existence of which property of light? a. polarization b. particle nature c. wave nature d. electromagnetic character

c