Chapter 17

53. The magnification produced by a plane mirror is ____________(sign and magnitude).

+1

49. When one observes a scratch on the bottom of a block of clear plastic, the scratch appears to be 2.4 cm below the top surface as viewed from above. The actual thickness of the plastic block is 3.0 cm. The index of refraction of the block is ______________.

1.25

37. 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. 0.188 B. 1.58º C. 0.333 D. nearly 90

A. 0.188

40. A ray of light traveling through water passes through an air bubble. Which path does it take? A. A B. B C. C D. D E. E

A. A

44. One day you see a beautiful rainbow to the west. What time of day is it? A. Morning. B. Noon. C. Afternoon. D. It could be any time during daylight.

A. Morning.

6. Which of the following lenses is a diverging lens? A. A [( B. B () C. C (l D. D ((

A. [(

46. While looking into a mirror, you notice that the image of a tree is projected onto the back of a chair (the positions of the tree and image are shown below). You must be looking into A. a concave mirror. B. a convex mirror. C. a plane mirror. D. a negative mirror.

A. a concave mirror.

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.

A. be refracted away from the normal to the surface in the air.

9. A shaving mirror and a make-up mirror both magnify the image. Thus, these mirrors are ___________ mirrors. A. concave B. convex C. plane

A. concave

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.

A. further away than it really is.

2. Light is refracted as it crosses the interface between two different media because A. it changes speed. B. it changes frequency. C. it becomes polarized. D. it loses energy.

A. it changes speed.

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.

A. less than the fish's actual distance.

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.

A. outer edge of the bow appears red and the inner edge appears blue or violet.

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.

A. real and inverted.

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.

A. the blue ray lies above the red ray and is more nearly horizontal than the red ray.

45. A beam of white light in air passes through the transparent object shown. Dispersion is observed to occur. From the diagram we can tell that A. the index of refraction is larger for red light than blue. B. the index of refraction is larger for blue light than red. C. the object acts as a converging lens. D. the object behaves like a concave mirror.

A. the index of refraction is larger for red light than blue.

23. A woman 1.6 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. 0.4 m. B. 0.8 m. C. 1.6 m. D. 3.2 m. E. impossible to say without knowing the viewing distance.

B. 0.8 m.

28. An object is placed 10 cm in front of a concave mirror of focal length 20 cm. The image will be formed 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. 0.05 cm behind the mirror.

B. 20 cm behind the mirror.

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.

B. a farsighted person to make rays from a nearby object diverge less strongly.

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.

B. at a single position determined by the distance of the object and the construction of the lens.

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.

B. blue light is bent more than red light.

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. concave B. convex C. converging D. plane

B. convex

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.

B. erect and virtual.

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.

B. in front of the retina.

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.

B. real for both, but the image is enlarged for the microscope and reduced for the telescope.

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.

B. smaller and inverted.

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.

B. the angle of reflection is the same as the angle of incidence.

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.

B. the focal point.

42. Lenses can be used to focus sunlight to a small point to burn paper or dry brush. A person who wears eyeglasses demonstrates this. From this you can tell that A. the person is nearsighted. B. the person is farsighted. C. the person is both near and farsighted. D. the person is either near or farsighted but not both.

B. the person is farsighted.

41. Two pools of water contain the same depth of water but one has a blue bottom and the other red. When looking into the pools from above, A. the blue bottom pool appears deeper. B. the red bottom pool appears deeper. C. the pools appear to have the same depth. D. it is not possible to tell which will appear deeper from this information.

B. the red bottom pool appears deeper.

20. In normal use, the image seen through eyeglasses is A. real. B. virtual. C. both A and B.

B. virtual.

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.

C. 16 cm.

15. A ray of light moves from air into water. Which path most accurately shows the refraction? A. A B. B C. C D. D E. E

C. C

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.

C. bend away from the normal on the air side.

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.

C. bent towards from the normal.

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

C. concave mirror

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.

C. long focal length for the objective and short focal length for the eyepiece.

51. Parallel light incident on a positive lens will ___________as it emerges.

Converge

48. A curved mirror that cannot produce a real image of an object is ______________________.

Convex

36. The speed of light in a certain type of glass is 40% slower than the speed of light in air. The index of refraction for that type of plastic is about A. 1.33. B. 1.4. C. 1.5. D. 1.67.

D. 1.67.

30. An object is placed 15 cm in front of a diverging lens of focal length -10 cm. The image will be located A. 0.167 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.

D. 6.0 cm in front of the lens.

43. Rays of light traveling through different media hit the boundary between the media and the air. The angle of incidence is the same in each case. Which medium has the largest index of refraction? A. A B. B C. C D. D

D. D

21. A ray of light in plastic reaches the edge of the plastic. The medium surrounding the plastic is air and the angle of incidence is larger than the critical angle. What will happen? A. The ray will refract out of the plastic, bending away from the normal line. B. The ray will refract out of the plastic, bending toward the normal line. C. The ray will experience total internal reflection, the angle of reflection being smaller the angle of incidence. D. The ray will experience total internal reflection, the angle of reflection equaling the angle of incidence. E. The ray will experience total internal reflection, the angle of reflection being larger the angle of incidence.

D. The ray will experience total internal reflection, the angle of reflection equaling the angle of incidence.

47. The image viewed in a telescope is a magnified virtual image. To achieve this, a telescope must have A. a negative objective lens with a large focal length. B. a negative eyepiece lens with a large focal length. C. a positive objective lens with a small focal length. D. a positive eyepiece lens with a small focal length.

D. a positive eyepiece lens with a small focal length.

10. The focal length of a glass lens depends on A. the curvature of the surface of the lens. B. the index of refraction of the glass. C. the intensity of the light passing through the lens. D. both the curvature of the surface of the lens and the index of refraction of the glass. E. both the index of refraction of the glass and the intensity of the light passing through the lens.

D. both the curvature of the surface of the lens and the index of refraction of the glass.

11. The cornea of the human eye is an example of a A. converging mirror. B. diverging lens. C. convex mirror. D. converging lens.

D. converging lens.

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 positive lens. B. converging or negative lens. C. diverging or positive lens. D. diverging or negative lens.

D. diverging or negative lens.

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.

D. diverging, to see distant objects.

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.

D. is thicker in the center than the edges.

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.

D. on a path parallel to the mirror axis.

8. A plane mirror will always produce a A. real, erect image. B. virtual, inverted image. C. real, inverted image. D. virtual, erect image.

D. virtual, erect image.

52. A prism decomposes incident white light into its constituent colors because of ________________.

Dispertion

50. Glasses prescribed to correct a farsighted eye will have a _______________ (sign) focal length.

Positive

56. An object is placed in front of a concave mirror. The object is farther from the mirror than the focal length of the mirror. The type of image reflected from the mirror is __________ and the orientation of the image is ___________.

Real/Inverted

54. The objective lens of a high-power microscope will have a ___________ (long, short) focal length and will be a __________ lens.

Short/Positive

55. Light passing from air into glass bends _________________the normal to the surface because it is traveling ____________ in the glass than in air.

Toward/Slower