Chapter 17: Light and Image Formation

Transcription

1 Chapter 17: Light and Image Formation 1. When light enters a medium with a higher index of refraction it is A. absorbed. B. bent away from the normal. C. bent towards from the normal. D. continues in the same direction. 2. Light is refracted as it crosses the interface between two different media because A. energy can neither be created nor destroyed. B. mass can be converted into energy but not vice versa. C. light can be thought of as both a wave and a particle. D. its speed is different in the two media. 3. When light is reflected from a smooth, plane mirror A. most of the light is scattered into multiple directions. B. the angle of reflection is the same as the angle of incidence. C. the light is changed to a lower frequency. D. the wave characteristics are predominant. 4. The image produced by a single diverging lens will ALWAYS be A. inverted and real. B. erect and virtual. C. erect and real. D. at infinity. E. inverted and virtual. 5. A converging lens A. always has a real image. B. refracts all light towards the focal point. C. always has two curved surfaces. D. is thicker in the center than the edges.

2 6. Which of the following lenses is a diverging lens? A B C D E 7. Light from the sun passes through a converging lens and forms an image at A. infinity. B. the focal point. C. the center of the lens. D. the center of curvature of the lens. 8. A plane mirror will always produce a A. real, erect image. B. virtual, inverted image. C. real, inverted image. D. virtual, erect image. 9. A shaving mirror and a make-up mirror both magnify the image. Thus, these mirrors are mirrors. A. concave B. convex C. plane 10. The focal length of a glass lens depends on A. the curvature of the surfaces of the lens. B. the index of refraction of the glass. C. the intensity of the light passing through the lens. D. both A and B. E. both B and C.

3 11. The cornea of the human eye is an example of a A. converging mirror. B. diverging lens. C. convex mirror. D. converging lens. 12. The unaided near-sighted human eye focuses light from a distant object A. behind the retina. B. in front of the retina. C. on the retina. D. acceptably, but is too short for the focusing power of the cornea. 13. The rear view mirror of an auto bears the legend Objects in mirror are closer than they appear. This mirror is a mirror. A. plane B. converging C. diverging D. useless 14. In the primary or inner rainbow, the A. outer edge of the bow appears red and the inner edge appears blue or violet. B. outer edge of the bow appears blue or violet and the inner edge appears red. C. outer edge of the bow appears yellow and the inner edge appears green. D. pot of gold is always at the left end. 15. Which of the following pictures most accurately shows light refracting through a smooth planar surface between air and water? Air Air Air Water Water Water A B C

4 16. A rainbow shows separate colors of the spectrum because, at raindrop surfaces, A. red light is bent more than green light. B. blue light is bent more than red light. C. green light is bent more than blue light. D. all colors are bent the same hence the separation. 17. Convex (converging) lenses are worn by A. a farsighted person to make rays from a distant object diverge more strongly. B. a farsighted person to make rays from a nearby object diverge less strongly. C. a nearsighted person to make rays from a distant object diverge more strongly. D. a nearsighted person to make rays from a nearby object diverge less strongly. 18. Rays from a distant object do not diverge enough for a nearsighted person to focus; this can be corrected with a A. converging or concave lens. B. converging or convex lens. C. diverging or concave lens. D. diverging or convex lens. 19. A fish looks up through the smooth surface of the water at a bear directly above it. To the fish, the bear appears to be A. further away than it really is. B. closer to the point directly above the fish than it really is. C. exactly where it really is. D. the bear cannot be seen by the fish, due to total internal reflection. 20. In normal use, the image seen through eyeglasses is A. real. B. virtual. C. both A and B. 21. If a nearsighted man views an object through a tiny hole in an opaque sheet near his eye, the object appears A. brighter and in better focus than without the paper. B. brighter but not as well focused as it is without the paper. C. dimmer but in better focus than without the paper. D. dimmer and not as well focused as it is without the paper.

5 22. A real image of a candle formed with a converging lens can be viewed on a screen placed A. at either focal point of the lens. B. at a single position determined by the distance of the object and the construction of the lens. C. anywhere on the side of the lens from which the light emerges. D. nowhere, that is, it can't be viewed on a screen at all. 23. A woman 1.8 m in height wants a plane mirror so that she can view her full height. The minimum vertical size of such a mirror is A. 3.6 m. B. 1.8 m. C. 0.9 m. D m. E. impossible to say without knowing the viewing distance. 24. A ray emerges from water (n = 1.33) into air. The light ray will A. emerge in air at the same angle as in the water. B. bend toward the normal on the air side. C. bend away from the normal on the air side. 25. Suppose a fish is observed below the surface of a lake. Looking down from above into the water (n = 1.33) the distance the fish appears below the surface is A. less than the fish's actual distance. B. equal to the fish's actual distance. C. greater than the fish's actual distance. 26. A ray of light traveling in a calm pond strikes the surface at an angle of incidence which is 5 less than the critical angle. This ray will A. be refracted away from the normal to the surface in the air. B. be refracted toward the normal to the surface in the air. C. undergo total internal reflection and not enter the air at all. 27. Which of the following optical elements used alone can produce a real image of an object? A. plane mirror B. negative lens C. concave mirror D. prism E. convex mirror 28. An object is placed 20 cm in front of a concave mirror of focal length 10 cm. The image will be formed

6 A. 20 cm in front of the mirror. B. 20 cm behind the mirror. C. 10 cm in front of the mirror. D. 10 cm behind the mirror. E cm behind the mirror. 29. The image of an object placed 20 cm in front of a concave mirror of focal length 10 cm will be A. real and inverted. B. real and erect. C. virtual and inverted. D. virtual and erect. 30. An object is placed 15 cm in front of a diverging lens of focal length -10 cm. The image will be located A cm in front of the lens. B. 3.0 cm behind the lens. C. 3.0 cm in front of the lens. D. 6.0 cm in front of the lens. E. 6.0 cm behind the lens. 31. A 1 cm object is placed 20 cm from a lens. The lens forms a real and inverted image of size 4.0 cm. What is the focal length of the lens? A. 8.0 cm. B. 12 cm. C. 16 cm. D. 20 cm. E. 24 cm. 32. A nearsighted person requires glasses with lenses that are A. converging, to see near objects. B. converging, to see distant objects. C. diverging, to see near objects. D. diverging, to see distant objects.

7 33. In order for a telescope to produce a large magnification one would select lenses of A. long focal length for both objective and eyepiece. B. short focal length for both objective and eyepiece. C. long focal length for the objective and short focal length for the eyepiece. D. short focal length for the objective and long focal length for the eyepiece. 34. One difference between a microscope and a telescope is that the image formed by the objective is A. real for the microscope, but virtual for the telescope. B. real for both, but the image is enlarged for the microscope and reduced for the telescope. C. real for both, but the image is reduced for the microscope and enlarged for the telescope. D. virtual for the microscope, but real for the telescope. 35. A raindrop is doing its part to form a primary rainbow. Red and blue light enter near the top of the raindrop together from the sun. Both red and blue are reflected once at the back surface of the drop, but when the two rays emerge on the sunward side A. the blue ray lies above the red ray and is more nearly horizontal than the red ray. B. the red ray lies above the blue ray and is more nearly horizontal than the blue ray. C. the blue ray lies below the yellow ray and is more nearly horizontal than the yellow ray. D. none of these. 36. The speed of light in a certain type of transparent plastic is 30% slower than the speed of light in air. The index of refraction for that type of plastic is about A B C D Light enters water (n = 1.33) from air. The incident light ray makes a 0.25 angle with the normal to the surface on the air side. What will be the angle made with the normal by the refracted ray on the water side? A B. 1.58º C D. nearly 90

8 38. If the image formed by a concave mirror is closer to the mirror than the object is, then compared to the object, the image will be A. larger and inverted. B. smaller and inverted. C. larger and erect. D. larger and real. 39. One ray that is useful in locating the image formed by a convex mirror is the ray that is incident on the mirror in a path directed toward the focal point. This ray is reflected A. through the center of curvature. B. directly back along its incident path. C. on a path tangent to the mirror. D. on a path parallel to the mirror axis. 40. A curved mirror that cannot produce a real image of an object is. Answer: convex 41. The magnification produced by a plane mirror is (sign and magnitude). Answer: When one observes a scratch on the bottom of a block of clear plastic, the scratch appears to be 2.5 cm below the top surface as viewed from above. The actual thickness of the plastic block is 3.5 cm. The index of refraction of the block is. Answer: Glasses prescribed to correct a farsighted eye will have a (sign) focal length. Answer: positive 44. The objective lens of a high-power microscope will have a (long, short) focal length and will be a lens. Answer: short, positive or converging 45. Parallel light incident on a negative lens will as it emerges. Answer: diverge 46. A prism decomposes incident white light into its constituent colors because of. Answer: dispersion 47. Light passing from air into glass bends the normal to the surface because it is traveling in the glass than in air. Answer: toward slower