WHS-CH-23 Light: Geometric Optics Show all your work, equations used, and box in your answers!

WHS-CH-23 Light: Geometric Optics Show all your work, equations used, and box in your answers! Willebrord Snell (1591-1626) Snell developed methods for measuring the Earth. He proposed the method of triangulation and this work is the foundation of geodesy. He also improved the classical method of calculating approximate values of π by polygons. Snell also discovered the law of refraction, a basis of modern geometric optics and also discovered the sine law. Multiple Choice 1. 2. 3. 4. What is the focal length of a lens if a candle is viewed at a distance of 4 m from the lens and the image is 2 m from the other side of the lens? (A) 2 m (B) 4/3 m (C) 3/4 m (D) 4/3 m A light ray is glass arrives at the glass-water interface at an angle of θ = 48 0 with respect to the normal. The refracted ray in the water makes an angle of 61 o with respect to the normal. If the angle of incidence changes to θ 25 0, what is the new angle of refraction in the water? (Use index of refraction of water = 1.33) (A) 16 0 (B) 54 0 (C) 30 0 (D) 24 0 The rear-view mirror on the passenger side of many cars has a warning: objects in mirror are closer than they appear. This implies that the mirror must be: (A) convex (B) transparent (C) concave (D) plane If two converging lenses with focal lengths of 10 cm and 20 cm are placed in contact, what is the power of the combination? (A) 10 D (B) 15 D (C) 20 D (D) 30 D 5. Optical density is proportional to: (A) index of refraction (B) index of reflection (C) mass density (D) light speed 1

6. 7. 8. 9. 10. 11. 12. 13. A girl of height h stands in front of a plane mirror. What must the minimum length of the mirror be, so she can view her entire body? (A) ¼ h (B) 2h (C) ½ h (D) h Relative to the mirror, where is the resulting image when a light source is placed 12 m in front of a diverging mirror that has a focal length of 6 m? (A) 2 m in front (B) 2 m behind (C) 4 m in front (D) 4 m in behind Light refracts when traveling from air into glass because light: (A) travels slower in glass than in air (B) travels slower in air than in glass (C) has a frequency that is greater in glass than in air (D) travels at the speed in glass and in air A blue object appears black when illuminated with which color of light? (A) Green (B) Yellow (C) Cyan (D) Blue A simple compound microscope normally uses a: (A) short focal length objective and a long focal length eyepiece (B) long focal length objective and a short focal length eyepiece (C) focal length objective and focal length eyepiece of the same length (D) short focal length objective and a short focal length eyepiece The image of a real object from a plane mirror has the following characteristics: (A) real, erect, with magnification =1 (B) real, inverted, with magnification =1 (C) real, erect, with magnification >1 (D) virtual, erect, with magnification =1 Which expression describes the critical angle for the interface of water with air? (Use index of refraction for water n = 1.33 and index of refraction for air n = 1) (A) sin -1 (1/3) (B) sin -1 (3/4) (C) sin -1 (2/3) (D) sin -1 (4/3) Using a mirror with a focal length of 10 m, an object is viewed at various distances. What is its magnification and orientation when the object is 5 m in front of the mirror? (A) Twice as large and upright (B) Twice as large and inverted (C) Half as large and upright (D) Same size and inverted 2

14. 15. 16. 17. 18. 19. 20. A candle is viewed through a lens. What is the magnification of the image when the candle is 6 m from the lens, and the image is 3 m from the lens on the other side? (A) Twice as large and upright (B) Same size and inverted (C) Half as large and upright (D) Half as large and inverted What is the focal length of the mirror if, when an object is 24 cm in front of a concave spherical mirror, the image is formed 3 cm in front of the mirror? (A) 1.5 cm (B) 2.7 cm (C) 5 cm (D) 6.3 cm What color light allows the investigator to see with the greatest resolution in a light microscope? (A) Red light because it is refracted less than other colors by the objective lens (B) Blue light because it has a shorter wavelength (C) Violet light because it has a longer wavelength (D) Blue light because it is brighter What is the distance between a lens and a screen so that when the screen and the converging lens of focal length f are arranged, an image of the Moon falls on the screen? Assume that the Moon is infinity away from the lens. (A) f/2 (B) 2f (C) f (D) infinity What is the orientation and magnification of the image of a light bulb if the light bulb is placed 2 m in front of a mirror and the image is 6 m behind the mirror? (A) Upright and 3x (B) Inverted and 3x (C) Upright and 0.5 x (D) Inverted and 1.5x The index of refraction of the core of a piece of fiber optic is 1.6. If the index of the surrounding classing is 1.3, what is the critical angle for total internal reflection of a light ray in the core, incident on the core-cladding interface? (A) 82 o (B) 40 o (C) 34 o (D) 54 o A light ray in water passes into air where the angle of incidence in the water is 42 o. What is the angle of refraction in the air? (Use index of refraction of air n = 1 and index of refraction of water = 1.33) (A) 63 o (B) 18 o (C) 46 o (D) 74 o 3

21. 22. The image of an object placed outside the focal point of a concave mirror is: (A) virtual and inverted (B) virtual and upright (C) real and inverted (D) real and upright If n1 is the index of refraction for the incident medium, and n2 is the index of the refracting medium, what conditions are necessary for the critical angle to exist? 23. 24. 25. 26. 27. 28. (A) n1 = n2 (B) n1< n2 (C) n1 < 2n2 (D) n1 > n2 Which statement about thin, single lenses is correct? (A) A diverging lens can only sometimes produce a virtual erect image (B) A diverging lens always produces a virtual erect image (C) A converging lens always produces a real inverted image (D) A diverging lens always produces a real inverted image Which statement is true if the magnification of a mirror or lens is negative? (A) Object is closer to the mirror or lens than to the image (B) Image is inverted (C) Image is erect and smaller than the object (D) Image is smaller than the object A lens of focal length 50 mm is used as a magnifier to view a 6.4 mm object that is positioned at the focal point of a lens. The user of the magnifier has a near point at 25 cm. What is the angular magnification of the magnifier? (A) 5 (B) 6.9 (C) 5.8 (D) 8.1 How does an image appear if an object is placed in front of a convex mirror at a distance larger than twice the magnitude of the local length of the mirror? (A) upright and smaller (B) inverted and larger (C) inverted and smaller (D) inverted and the same size A 1.8 x 10 14 Hz electromagnetic wave propagates in CCL4 with a speed of 2.43 x 10 8 m/s. What is the wavelength of the same wave in a vacuum? (Use speed of light in a vacuum c = 3 x 10 8 m/s) (A) 2,260 nm (B) 1,280 nm (C) 1,040 nm (D) 1,667 nm As the angle of an incident ray of light increases, the angle of the reflected ray: (A) increases (B) decreases (C) stays the same (D) increases or decreases 4

29. 30. 31. 32. 33. 34. If parallel light rays were incident on a lens of power 4 D, which statement is true for the rays on the other side of the lens? (A) The rays diverge as if from a point 4 m behind the lens (B) The rays diverge as if from a point ¼ m in front of the lens (C) The rays converge with a focal length of ¼ m (D) The rays converge with a focal length of 4 m What is the minimum thickness of a soap film that reflects a given wavelength of light? (A) ¼ the wavelength (B) ½ the wavelength (C) One wavelength (D) Two wavelengths At what distance from a concave spherical mirror (with a focal length of 100 cm) must a woman stand in order to see an upright image of herself that is twice her actual height? (A) 100 cm (B) 50 cm (C) 300 cm (D) 25 cm If a person s eyeball is too long from front to back, what is the name of the condition that the person likely suffers? (A) Hyperopia (B) Astigmatism (C) Presbyopia (D) Myopia A candle 18 cm tall sits 4 m away from a diverging lens with a focal length of 3 m. What is the size of the image? (A) 6.3 cm (B) 7.7 cm (C) 2.9 cm (D) 13.5 cm Questions 34-35 are based on the following: A tank holds a layer of oil 1.58 m thick that floats on a layer of syrup that is 0.66 m thick. Both liquids are clear and do not intermix. A ray, which originates at the bottom of the tank on a vertical axis (see figure), crosses the oil-syrup interface at a point 0.9 m to the right of the vertical axis. The ray continues and arrives at the oil-air interface, 2 m from the axis and at the critical angle. (Use the refractive index n = 1 for air) The index of refraction of the oil is closest to: (A) 1.39 (B) 1.56 (C) 1.75 (D) 1.82 5

35. 36. 37. 38. 39. 40. 41. What is the index of refraction of the syrup? (A) 1.53 (B) 1.46 (C) 1.17 (D) 1.24 Which of the following cannot be explained with the wave theory of light? (A) Photoelectric effect (B) Interference (C) Polarization (D) Diffusion The use of wave fronts and rays to describe optical phenomena is known as: (A) dispersive optics (B) reflective optics (C) wave optics (D) geometrical optics In the investigation of a new type of optical fiber (index of refraction n = 1.26), a laser beam is included on the flat end of a straight fiber in air, as shown. What is the maximum angle of incidence (ø1) if the beam is not to escape from the fiber? (A) 36 o (B) 43 o (C) 58 o (D) 50 o An object is placed at a distance of 0.5 m from a converging lens with a power of 10 diopters. At what distance from the lens does the image appear? (A) 0.13 m (B) 0.47 m (C) 0.7 m (D) 1.5 m A virtual image is: I. produced by light rays II. the brain s interpretation of light rays III. found only on a concave mirror (A) I only (B) II only (C) III only (D) I and II only If the index of refraction of diamond is 2.43, a given wavelength of light travels: (A) 2.43 times faster in diamond than it does in air (B) 2.43 times faster in a vacuum than it does in diamond (C) 2.43 times faster in diamond than it does in a vacuum (D) 2.43 times faster in air than it does in diamond 6

42. 43. 44. 45. 46. 47. 48. 49. A sheet of red paper appears black when it is illuminated with: (A) orange light (B) cyan light (C) red light (D) yellow light When viewed straight down (90 o to the surface), an incident light ray moving from water to air is refracted: (A) 37 o away from the normal (B) 37 o toward the normal (C) 28 o toward the normal (D) 0 o A glass plate with an index of refraction of 1.45 is immersed in a liquid. The liquid is an oil with an index of refraction of 1.35. The surface of the glass is inclined at an angle of 54 o with the vertical. A horizontal ray in the glass is incident on the interface of glass and liquid. The incident horizontal ray reflects at the interface. The angle that the refracted ray in the oil makes with the horizontal is closest to: (A) 8.3 o (B) 14 o (C) 6 o (D) 12 o Two plane mirrors make an angle of 30 o. A light ray enters the system and is reflected once off each mirror. Through what angle is the ray turned? (A) 60 o (B) 90 o (C) 120 o (D) 160 o The angle of incidence: (A) may be greater than, less than, or equal to the angle of refraction (B) is always less than the angle of refraction (C) must equal the angle of refraction (D) is always greater than the angle of refraction If a person s eyeball is too short from front to back, the person is likely to suffer from: (A) nearsightedness (B) farsightedness (C) presbyopia (D) astigmatism The shimmering that is observed over a hot surface is: (A) changing refraction from the mixing of warm and cool air (B) a mirage (C) heat rays (D) reflections from evaporating water vapor Which color of the visible spectrum has the shortest wavelength (400 nm)? (A) Violet (B) Green (C) Orange (D) Blue 7

50. 51. 52. 53. 54. 55. 56. When neon light passes through a prism, what is observed? (A) White light (B) Bright spots or lines (C) The same neon light (D) Continuous spectrum The law of reflection holds for: I. plane mirrors II. curved mirrors III. spherical mirrors (A) I only (B) II only (C) III only (D) I, II, and III only Light with the lowest (longest wavelength) detected by your eyes is perceived as: (A) red (B) green (C) yellow (D) orange A 0.1 m tall candle is observed through a converging lens that is 3 m away and has a focal length of 6 m. The resulting image is: (A) 3 m from the lens on the opposite side of the object (B) 6 m from the lens on the opposite side of the object (C) 3 m from the lens on the same side as the object (D) 6 m from the lens on the same side as the object A double-concave lens has equal radii of curvature of 15 cm. An object placed 14 cm from the lens forms a virtual image 5 cm from the lens. What is the index of refraction of the lens material? (A) 0.8 (B) 1.4 (C) 2 (D) 2.6 The magnification m for an object reflected from a mirror is the ratio of what characteristic of the image to the object? (A) Center of curvature (B) Distance (C) Orientation (D) Angular size When two converging lenses of equal focal lengths are used together, the effective combined focal length is less than the focal length of either on of the individual lens. The combined power of the two lenses used together is: (A) greater than the power of either individual lens (B) the same as the power of either individual lens (C) less than the power of either individual lens (D) greater than the sum of the powers of both individual lens 8

57. 58. 59. 60. 61. 62. 63. In the figure a ray arrives at the glass water interface at an angle of 48 o with the normal. The refracted ray makes an angle of 68 o with the normal. If another ray in the glass makes an angle of 29 o with the normal, what is the angle of refraction in the water? (Use the index of refraction of water n = 1.33) (A) 29 o (B) 37 o (C) 31 o (D) 46 o In a compound microscope: (A) the image of the objective serves as the object for the eyepiece (B) magnification is provided by the objective and not by the eyepiece. The eyepiece merely increases the brightness of the image viewed (C) magnification is provided by the objective and not by the eyepiece. The eyepiece merely increases the resolution of the image viewed (D) both the objective and the eyepiece form real images The radius of curvature of the curved side of a convex lens made of glass is 33 cm. What is the focal length of the lens? (Use index of refraction for glass n = 1.64) (A) 28 cm (B) 28 cm (C) 38 cm (D) 52 cm The part of the electromagnetic spectrum most absorbed by water is: (A) lower frequencies in the visible (B) higher frequencies in the visible (C) infrared (D) ultraviolet Which color of the visible spectrum has photons with the most energy? (A) Violet (B) Green (C) Orange (D) Red The colors of an oil slick are caused by reflection and: (A) refraction (B) polarization (C) diffraction (D) interference A lens has a focal length of 2 m. What lens could you combine with it to get a combination with a focal length of 3 m? (A) A lens of power 1/3 diopters (B) A lens of power 6 diopters (C) A lens of power 2/6 diopters (D) A lens of power 1/6 diopters 9

64. 65. 66. 67. 68. 69. 70. An incident ray traveling in air makes an angle of 30 o with the surface of a medium with an index n = 1.73. What is the angle that the refracted ray makes with the surface? (Use the index of refraction for air n = 1) (A) 30 o (B) 90 sin -1 (0.5) (C) 60 o (D) sin -1 (0.5) A mirage is produced because: (A) light travels faster through air than through water (B) images of water are reflected from the sky (C) water from oceans and lakes is highly reflective (D) warm air has a higher index of refraction than cool air A material which has the ability to rotate the direction of polarization of linearly polarized light is said to be: (A) diffraction limited (B) optically active (C) circularly polarized (D) birefringent The angle of incidence can vary between zero and: (A) 2π radians (B) π radians (C) π/2 radians (D) 1 radian An amateur astronomer grinds a double-convex lens whose surface have radii of curvature of 40 cm and 60 cm. What is the focal length of this lens in air? (Use index of refraction for glass n = 1.54) (A) 44 cm (B) 88 cm (C) 132 cm (D) 22 cm When light reflects from a stationary surface, there is a change in its: (A) I and II only (B) I and III only (C) III only (D) none of the above I. frequency II. speed III. wavelength If a distant galaxy is moving away from the Earth at 4,300 km/s, how do the detected frequency (fdet) and λ of the visible light detected on Earth compare to the f and λ of the light emitted by the galaxy? (A) The (fdet) is lower and the λ is shifted toward the red end of the visible spectrum (B) The (fdet) is lower and the λ is shifted towards the blue end of the visible spectrum (C) The (fdet) is the same, but the λ is shifted towards the red end of the visible spectrum (D) The (fdet) is the same, but the λ is shifted towards the blue end of the visible spectrum 10

71. 72. 73. 74. 75. 76. 77. What is the frequency of a radio wave with a wavelength of 2.2 m? (A) 3 x 10 6 Hz (B) 1.36 x 10 6 Hz (C) 7.3 x 10 6 Hz (D) 2.2 x 10 6 Hz A ray of light is incident from a layer of crown glass (n = 1.52) upon a layer of water (n = 1.33). The critical angle of incidence for this situation is equal to (A) 32 o (B) 41 o (C) 49 o (D) 61 o The relative index of refraction between two media is 1.20. Compared to the velocity of light in medium 1, the velocity of light in medium 2 will be: (A) greater by 1.2 times (B) reduced by 1.2 times (C) the same (D) The velocity will depend on the two media What is the approximate angle of refraction for a ray of light incident from air on a piece of quartz at a 37 o angle? (A) 24 o (B) 37 o (C) 42 o (D) 66 o If the velocity of light in a medium depends on its frequency, the medium is said to be (A) refractive (B) resonant (C) diffractive (D) dispersive If the intensity of a monochromatic ray of light is increased while the ray is incident on a pair of narrow slits, the spacing between maxima in the diffraction pattern will be (A) increased (B) decreased (C) the same (D) increased or decreased, depending on the frequency In the diagram, source of light (S) sends a ray toward the boundary between two media in which the relative index of refraction is less than 1. The angle of incidence is indicated by i. Which ray best represents the path of the refracted light? (A) A (B) B (C) C (D) D 11

78. 79. 80. 81. 82. 83. 84. 85. Which material will produce a converging lens with the longest focal length? (A) Lucite (B) Crown glass (C) Flint glass (D) Quartz An object is placed in front of a converging lens in such a way that the image produced is inverted and larger. If the lens were replaced by one with a larger index of refraction, the size of the image would: (A) increase (B) decrease (C) increase or decrease, depending on the degree of change (D) remain the same A negative image distance means that the image formed by a concave mirror will be (A) real (B) erect (C) inverted (D) smaller Real images are always produced by (A) plane mirrors (B) convex mirrors (C) concave lenses (D) convex lenses The focal length of a convex mirror with a radius of curvature of 8 cm is (A) 4 cm (B) 4 cm (C) 8 cm (D) 8 cm A shadow is formed by a point source of light. Upon closer inspection, the edges of the shadow seem to be diffuse and fuzzy. This phenomenon is probably caused by: (A) dispersion as the different wavelengths of light focus at different points (B) refraction as the rays are bent by their contact with the shadow forming surface (C) diffraction as the waves nearest the edge of the shadow-forming surface are sources for waves going into the shadow region (D) dispersion as the different wavelengths are traveling at slightly different speeds in the new Medium As the angle of incidence for a ray of light passing from glass to air increases, the critical angle of incidence for the glass: (A) increases (B) decreases (C) increases and then decreases (D) remains the same The flapping of a flag in the wind is best explained using (A) Archimedes (B) Bernoulli s principle (C) Newton s principle (D) Pascal s principle 12

86. 87. 88. 89. 90. 91. A light ray is incident on a glass-air interface as shown above. Which path will the light ray follow after it enters the air? (A) A or B (B) B or C (C) E (D) D Questions 87-91 REFER TO THE FOLLOWING INFORMATION: Light with a wavelength of 5.4 x 10-7 m falls on two slits that are separated by a distance of 1.0 x 10-3 m. An interference pattern forms on a screen 2 m away. What is the energy of each photon of this light? (A) 3 x 10 8 J (B) 4 x 10-8 J (C) 3 x 10-33 J (D) 4 x 10-19 J What is the approximate distance between the central bright band and the next bright band? (A) 2 m (B) 1.08 x 10-3 m (C) 2.7 x 10-3 m (D) 3.6 x 10-3 m The dark and bright interference pattern observed on the screen is caused by: (A)reflection and refraction (B) refraction and diffraction (C) polarization and interference (D) diffraction and interference If the distance between the slits and the screen is increased, the pattern spacing will: (A) increase (B) decrease (C) increase and then decrease (D) remain the same If light with a shorter wavelength is used in an experiment, the pattern separation will: (A) increase (B) decrease (C) increase and then decrease (D) remain the same 13

92. 93. 94. 95. 96. 97. As light enters a slower medium (index of refraction N2) from a faster one (index of refraction N1), its wavelength is observed to be cut down to 1/3 of its previous value. What is the ratio of N2/N1? (A) 1.0 (B) 3.0 (C) 0.33 (D) The frequency and/or wavelength must be specified What is the critical angle for light within a transparent material (N = 2.0) when immersed in water (N = 1.3)? (A) 30 o (B) 60 o (C) 41 o (D) No critical angle in this situation The fact that two oncoming headlights of a car cannot be resolved at large distances (i.e. the two light sources are seen as one) is best described by: (A) wave interference (B) refraction (C) dispersion (D) diffraction A beam of monochromatic light entering a glass window pane from the air will experience a change in: (A) frequency and wavelength (B) speed and wavelength (C) speed only (D) wavelength only Which of the following changes to a double slit interference experiment would increase the widths of the fringes in the interference pattern that appears on the screen? (A) Use light of a shorter wavelength (B) Move the screen closer to the slit (C) Move the slits closer together (D) Use light with a lower wave speed Consider two adjacent transparent media. The speed of light in Medium 1 is v1, and the speed of light in Medium 2 is v2. If v1 < v2, then total internal reflection will occur at the interface between these media if a beam of light is: (A) incident in Medium 1 and strikes the interface at an angle of incidence greater than sin -1 (v1/v2) (B) incident in Medium 1 and strikes the interface at an angle of incidence greater than sin -1 (v2/v1) (C) incident in Medium 2 and strikes the interface at an angle of incidence greater than sin -1 (v1/v2) (D) incident in Medium 2 and strikes the interface at an angle of incidence greater than sin -1 (v2/v1) 14

98. In the figure, a ray of light hits an object and travels parallel to the principal axis as shown by the dotted line. Which line shows the correct continuation of the ray after it hits the concave lens? (A) a (B) b (C) c (D) d 99. Ultraviolet light has a wavelength of about 6 x 10-8 m. What is the frequency of this light? (A) 5 x 10 15 Hz (B) 0.5 Hz (C) 2 Hz (D) 20 Hz 100. 101. 102. In the figure above, a ray of light travels through three different regions (mediums) as shown. List the three regions in order of increasing index of refraction. (A) ABC (B) CBA (C) ACB (D) BCA When a light wave in air hits a thin film (nfilm > nair), part of the wave is transmitted into the film and part is reflected. At the bottom of the thin film part of the wave is transmitted into air and part is reflected back up. What can you say about the f=reflected wave s phase at the top layer and bottom layers? (A) Only the top reflection is inverted (B) Only the bottom is reflection is inverted (C) Neither reflection is inverted (D) Both reflections are inverted Optometrists use a linear scale of lens power, measured in diopters, to prescribe corrective lenses. Sufferers of myopia, or nearsightedness, have difficulty resolving distant objects because the lenses in their eyes are too strong. If a myopic person has a prescription of 5 diopters, what image do her corrective lenses create for distant objects? (A) an upright, real image about 20 cm in front of her eyes (B) an upright, virtual image about 20 cm in front of her eyes (C) an inverted, real image about 20 cm behind her eyes (D) an inverted, virtual image 4 cm behind her eyes 15

103. 104. In Young s double slit interference experiment, what is the difference in path length of the light waves from the two slits at the center of the first bright fringe above the central maximum? (A) 0 (B) ¼ λ (C) ½ λ (D) λ A beam of light in air is incident upon the smooth surface of a piece of flint glass, as shown: If the reflected beam and refracted beam are perpendicular to each other, what is the index of refraction of the glass? (A) 1 2 105. 106. 107. (B) 1 2 3 (C) 3 (D) 2 3 When green light (wavelength = 500 nm in air) travels through diamond (refractive index = 2.4), what is its wavelength? (A) 208 nm (B) 357 nm (C) 500 nm (D) 700 nm Questions 106-107 The figure to the right shows a beam of light striking the surface of a piece of glass from the air. If the reflected beam and refracted beam are perpendicular to each other, what is the index of refraction of the glass? (A) sin 55 o (B) 1/sin 55 o (C) 1/sin 35 o (D) sin55 o /sin35 o Let n denote the index of refraction of the glass. If the incident light has a frequency of f when traveling through the air, what is the wavelength of the light when it travels through the glass? (A) fc / n (B) n / fc (C) c/ f (D) c / nf 16

Questions 108-11 In the diagram accompanying each question, representing light rays from an illuminated object (labeled O in the diagram) interact with an optical device (or devices); A mirror, a lens or a combination of both. In each case, identify the optical device(s) from among the choices below that is/are most likely in the dotted box. (A) Plane mirror (B) Converging lens (C) Diverging lens (D) Plane mirror and a converging lens 108. 109. 110. 111. 112. What principle is the basis for the transmission of light through glass (fiber optic) cables, allowing the signal to be sent even if the cable is bent? (A) Photoelectric effect (B) Light diffraction (C) Light polarization (D) Total internal reflection 17

SHOW ALL WORK FOR THE FOLLOWING CALCULATIONS IN THE FORMAT REQUIRED 1. A convex mirror has a focal length of -10 cm. An object 4 cm high is placed 20 cm in front of the mirror. Find the position and size of the image. Describe the nature of the image. 2. An object 6 cm tall is placed 2 cm in front of a convex lens wit a focal length 10 cm. Determine the position, size, and nature of the image. 3. Eyeglasses make use of which property exhibited by light? (a) dispersion (b) reflection (c) refraction (d) interference (e) diffraction 4. An illuminated arrow is placed 2 cm in front of a diverging lens with focal length -6 cm. The image is (a) real, inverted, smaller than the object (b) virtual, inverted, larger than the object (c) virtual, upright, larger than the object (d) real, upright, larger than the object (e) virtual, upright, smaller than the object 5. A concave mirror with radius of curvature 1.5 m is used to collect light from a distant source. The distance between the image formed and the mirror is? 6. An illuminated arrow 2 cm high is placed 15 cm from a converging lens (along the axis) of focal length 10 cm. The size of the image is? 7. The figure above show two walls of an empty fish tank so that air (n = 1) is on either side of the glass (n = 1.5). The glass is 0.5 cm thick. A ray R is incident on the glass at a 30 0 angle with the normal as shown. (a) On the left figure, continue the ray, showing qualitatively what happens at the next interface. (b) At what distance above the normal N will the transmitted ray emerge out of the glass? (c) Determine the incident angle at the second interface that will ensure total internal reflection. Could the initial ray R have its incident angle adjusted to make this happen? Explain. (d) Suppose the tank is filled with water (n = 1.33). On the right figure provided continue the ray, showing qualitatively what happens at the glass-water interface. 8. A beam of laser light in a room is pointed at a diamond, index of refraction 2.42. What is the critical angle for the light entering the diamond? 9. A ray of light is incident from a layer of crown glass (n = 1.52) upon a layer of water (n = 1.33). The critical angle of incidence for this situation is equal to? 18

10. A ray of light ( 680 nm red ) enters an isosceles right prism as shown above. The index of refraction for this wavelength is 1.22 in the prism. Assume air surrounds the prism. (a) On the right figure, continue the ray to the next interface and show the behavior qualitatively at this interface. (b) Find the wavelength of the light in the prism. (c) Determine the angle that the ray leaving the prism makes with the original direction of the ray, shown as the thin line in the figure. (d) Violet light of wavelength (in air) 460 nm with an index of refraction 1.26 is added to the ray so that both colors are in the ray. Determine the angular separation of the two rays as they leave the prism. (e) The prism is now immersed in a transparent liquid with an index of refraction that is 1.50 for both colors. On the second figure, continue the ray and show the qualitative behavior at the second interface. 11. A converging lens with focal length 4 cm has an object placed 6 cm in front of it as shown above. A diverging lens with focal length -8 cm is placed 28 cm behind the first lens. (a) Determine the position of the image formed by the first lens. (b) On the figure, draw the rays needed to display this image (three lines). (c) What is the magnification of this image? (d) Determine the position of the image formed by the second lens. (e) On the figure, sketch the rays needed to display this image (three lines). (f) Find the overall magnification of this lens system. What is the nature of the final image? END OF ASSIGNMENT 19

NAME: PERIOD: DATE: / / CHAPTER 23 WORKSHEET LIGHT: GEOMETRIC OPTICS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 76. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. PHYSICSINMOTION 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. 93. 94. 95. 96. 97. 98. 99. 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 20