1. You stand two feet away from a plane mirror. How far is it from you to your image? a. 2.0 ft c. 4.0 ft b. 3.0 ft d. 5.0 ft

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1 Lenses and Mirrors 1. You stand two feet away from a plane mirror. How far is it from you to your image? a. 2.0 ft c. 4.0 ft b. 3.0 ft d. 5.0 ft 2. Which of the following best describes the image from a plane mirror? a. virtual and magnification greater than c. virtual and magnification equal to b. real and magnification less d. real and magnification equal to 3. When the reflection of an object is seen in a plane mirror, the image is: a. real and upright. c. virtual and upright. b. real and inverted. d. virtual and inverted. 4. When the reflection of an object is seen in a concave mirror the image will: a. always be real. c. may be either real or virtual. b. always be virtual. d. will always be enlarged. 5. When the reflection of an object is seen in a convex mirror the image will: a. always be real. c. may be either real or virtual. b. always be virtual. d. will always be enlarged. 6. Parallel rays of light that hit a concave mirror will come together: a. at the center of curvature. c. at a point half way to the focal point. b. at the focal point. d. at infinity. 7. An object is placed at a distance of 50 cm from a thin lens along the axis. If a real image forms at a distance of 40 cm from the lens, on the opposite side from the object, what is the focal length of the lens? a. 22 cm c. 90 cm b. 45 cm d. 200 cm 8. Which of the following effects is the result of the fact that the index of refraction of glass will vary with wavelength? a. spherical aberration c. chromatic aberration b. mirages d. light scattering 9. Use of a parabolic mirror, instead of made of a circular arc surface, can be used to reduce the occurrence of which of the following effects? a. spherical aberration c. chromatic aberration b. mirages d. light scattering 10. How large should a wall-mounted mirror be to view the upper half of s height, h? a. h c. h/4 b. h/2 d. The answer is not given. 11. The real image of an object is located 45.0 cm away from a concave mirror, which has a focal length of 10.0 cm. How far is the object from the mirror? a cm c cm b cm d cm 1

2 12. A concave mirror forms a real image at 25.0 cm from the mirror surface along the principal axis. If the corresponding object is at a 10.0-cm distance, what is the mirror s focal length? a cm c cm b cm d cm 13. If a virtual image is formed along the principal axis 10 cm from a concave mirror with the focal length 15 cm, what is the object distance from the mirror? a. 30 cm c. 12 cm b. 10 cm d. 6.0 cm 14. If a virtual image is formed 10.0 cm along the principal axis from a convex mirror of focal length 15.0 cm, how far is the object from the mirror? a cm c cm b cm d cm 15. A woman looking in a makeup mirror sees her face at twice its actual size and right-side up. If she is 28.0 cm from the mirror, what is its focal length? a cm c cm b cm d cm 16. Which of the following best describes the image of a concave mirror when the object is at a distance greater than twice the focal point distance from the mirror? a. virtual, upright and magnification greater c. virtual, upright and magnification less b. real, inverted and magnification less than d. real, inverted and magnification greater 17. Which of the following best describes the image of a concave mirror when the object s distance from the mirror is less than the focal point distance? a. virtual, upright and magnification greater c. virtual, upright and magnification less b. real, inverted and magnification less than d. real, inverted and magnification greater 18. Which of the following best describes the image of a convex mirror when the object s distance from the mirror is less than the absolute value of the focal point distance? a. virtual, upright and magnification greater c. virtual, upright and magnification less b. real, inverted and magnification less than d. real, inverted and magnification greater 19. A convex mirror with focal length of 20 cm forms an image 12 cm behind the surface. Where is the object located as measured from the surface? a. 7.5 cm c. 22 cm b. 15 cm d. 30 cm 20. A convex mirror with a focal length of 20 cm forms an image 15 cm behind the surface. If the object height is 1.2 cm what is the image height? a cm c cm b cm d. 3.0 cm 2

3 21. An object placed 12 cm from a concave mirror produces a real image 8.0 cm from the mirror. If the object is now moved to a new position 18.0 cm from the mirror, where is the new image located as measured from the mirror? a. 3.0 cm c. 9.2 cm b. 6.5 cm d cm 22. An object is held at a distance of 12 cm from a convex mirror creating an image that is 1/3 the object size. What is the focal length of the mirror? a. 6.0 cm c. 9.0 cm b. 3.0 cm d. 18 cm 23. A candle is 49.0 cm in front of a convex spherical mirror of radius of curvature 70.0 cm. What are the image distance and the magnification, respectively? a cm, c cm, b cm, d cm, An object 2 cm high is placed 10 cm in front of a mirror. What type of mirror and what radius of curvature is needed for an image that is upright and 4 cm tall? a. Concave, R = 20 cm c. Convex, R = 10 cm b. Concave, R = 40 cm d. Convex, R = 20 cm 25. An object is 12.0 cm from the surface of a spherical Christmas tree ornament that is 8.00 cm in diameter. What is the magnification of the image? a c b d Ron fills a beaker with glycerin (n = 1.473) to a depth of 5.0 cm. If he looks straight down through the glycerin surface, he will perceive the liquid to be what apparent depth? a. 7.4 cm c. 3.4 cm b. 5.0 cm d. 1.0 cm 27. A glass block, for which n = 1.52, has a blemish located 3.2 cm from surface. At what distance from that surface does the image of the blemish appear to the outside observer? a. 1.6 cm c. 4.9 cm b. 2.1 cm d. 6.4 cm 28. A container is filled with fluid 1, and the apparent depth of the fluid is 5.00 cm. The container is next filled with fluid 2, and the apparent depth of this fluid is 4.00 cm. If the index of refraction of the first fluid is 1.60, what is the index of refraction of the second fluid? a c b d. More information is needed to find the value. 29. An object of length 3.00 cm is inside a plastic block with index of refraction If the object is viewed from directly above, what is the length of its image? a cm c cm b cm d cm 3

4 30. A 3.0 cm tall object is placed along the principal axis of a thin convex lens of 30.0 cm focal length. If the object distance is 40.0 cm, which of the following best describes the image distance and height, respectively? a cm and 7.0 cm c cm and 1.3 cm b. 120 cm and 9.0 cm d. 120 cm and 1.0 cm 31. Which of the following best describes the image for a thin convex lens that forms whenever the object is at a distance less focal length from the lens? a. inverted, enlarged and real c. upright, diminished and virtual b. upright, enlarged and virtual d. inverted, diminished and real 32. An object is placed at a distance of 30 cm from a thin convex lens along its axis. The lens has a focal length of 10 cm. What are the values, respectively, of the image distance and magnification? a. 60 cm and 2.0 c. 60 cm and 0.50 b. 15 cm and 2.0 d. 15 cm and Sally places an object 6.0 cm from a thin convex lens along its axis. The lens has a focal length of 9.0 cm. What are the respective values of the image distance and magnification? a. 18 cm and 3.0 c. 3.0 cm and 0.50 b. 18 cm and 3.0 d. 18 cm and Ansel places an object 30 cm from a thin convex lens along the axis. If a real image forms at a distance of 10 cm from the lens, what is the focal length of the lens? a. 30 cm c. 10 cm b. 15 cm d. 7.5 cm 35. Ellen places an object 40.0 cm from a concave lens. If a virtual image appears 10.0 cm from the lens on the same side as the object, what is the focal length of the lens? a cm c cm b cm d cm 36. A projector lens is needed to form an image on a screen 10 times the size of its corresponding object. The screen is located 8.0 m from the lens. What is the required focal length of the lens? a m c m b m d m 37. An object, located 90 cm from a concave lens, forms an image 60 cm from the lens on the same side as the object. What is the focal length of the lens? a. 36 cm c. 180 cm b. 75 cm d. 150 cm 38. An object and a screen are separated by cm. A convex lens is placed between them, 5.00 cm from the object. In this position it causes a sharp image of the object to form on the screen. What is the focal length of the lens? a cm c cm b cm d cm 39. For a converging lens with two curved surfaces, the radius of curvature for both surfaces is 10 cm. If the focal length is 10 cm, what must the index of refraction be? a. 1.5 c. 2.5 b. 2.0 d

5 40. For a diverging lens with flat surface, the radius of curvature for the curved surface is 20.0 cm. What must the index of refraction be so that the focal length is 15.0 cm? a c b d What is the image distance of an object 1.00 m in front of a converging lens of focal length 20.0 cm? a cm c cm b cm d cm 42. When an image is inverted compared to the object, it is also: a. virtual. c. enlarged. b. reversed left to right. d. diminished. 43. A 100-cm focal length thin lens is placed in contact with of 66.7 cm focal length. An object is placed 50 cm in front of the combination. What is the image distance? a. 40 cm c. 67 cm b. 25 cm d. 200 cm 44. A 100-cm focal length thin lens is placed in contact with of 66.7 cm focal length. A 3.0 cm tall object is placed 50 cm in front of the combination. What is the size of the image? a. 3.8 cm c. 4.0 cm b. 1.9 cm d. 12 cm 45. Three thin lenses, each of focal length f, are placed in contact. What is the resulting focal length of the combination? a. f c. f/3 b. 3f d. 3/f 5

6 ID: A Lenses and Mirrors Answer Section MULTIPLE CHOICE 1. C 2. C 3. C 4. C 5. B 6. B 7. A 8. C 9. A 10. C 11. D 12. D 13. D 14. A 15. D 16. B 17. A 18. C 19. D 20. A 21. B 22. A 23. A 24. B 25. C 26. C 27. B 28. A 29. A 30. B 31. B 32. D 33. A 34. D 35. B 36. C 37. C 38. C 39. A 40. C 1

7 ID: A 41. C 42. B 43. D 44. D 45. C 2