# Unit 13 Review

Reflection and Refraction

 Navigate to Answers for: [ Questions #1-#12 | Questions #13-#24 | Questions #25-#36 | Questions #37-#49 ] [ #37 | #38 | #39 | #40 | #41 | #42 | #43 | #44 | #45 | #46 | #47 | #48 | #49 ]

37. A 3 cm tall object is placed along the principal axis of a thin converging lens of 30 cm focal length. If the object distance is 40 cm, which of the following best describes the image distance and height, respectively?

 a. 17.3 cm and 7.0 cm b. 120.0 cm and -9.0 cm c. 17.3 cm and 1.3 cm d. 120.0 cm and -1.0 cm

The Mathematics of Lenses (7 seconds)

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38. Which of the following best describes the image for a thin converging lens that forms whenever the object is at a distance less than one focal length from the lens?

 a. inverted, enlarged and real b. upright, enlarged and virtual c. upright, reduced and virtual d. inverted, reduced and real

Ray Diagrams (15 seconds) | Object-Image Relations (9 seconds)

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39. Which of the following best describes the image for a thin diverging lens that forms whenever the magnitude of the object distance is less than that of the lens' focal length?

 a. inverted, enlarged and real b. upright, enlarged and virtual c. upright, reduced and virtual d. inverted, reduced and real

Ray Diagrams (9 seconds) | Object-Image Relations (5 seconds)

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40. An object is placed at a distance of 30 cm from a thin converging 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 2.00 b. 15 cm and 2.00 c. 60 cm and -0.50 d. 15 cm and -0.50

The Mathematics of Lenses (7 seconds)

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41. An object is placed at a distance of 6 cm from a thin converging lens along its axis. The lens has a focal length of 9 cm. What are the values, respectively, of the image distance and magnification?

 a. -18 cm and 3 b. 18 cm and 3 c. 3 cm and -0.5 d. -18 cm and -3

The Mathematics of Lenses (7 seconds)

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42. An object is placed at a distance of 30 cm from a thin converging 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 b. 15 cm c. 10 cm d. 7.5 cm

The Mathematics of Lenses (7 seconds)

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43. An object is placed at a distance of 40 cm from a thin lens along the axis. If a virtual image forms at a distance of 50 cm from the lens, on the same side as the object, what is the focal length of the lens?

 a. 22 cm b. 45 cm c. 90 cm d. 200 cm

The Mathematics of Lenses (7 seconds)

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44. Atmospheric refraction of light rays is responsible for which one of the following effects?

 a. spherical aberration b. mirages c. chromatic aberration d. light scattering

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45. If atmospheric refraction did not occur, how would the apparent time of sunrise and sunset be changed?

 a. both would be later b. both would be earlier c. sunrise would be later and sunset earlier d. sunrise would be earlier and sunset later

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46. Distinguish between diffuse and regular (specular) reflection in terms of both cause and result.

Specular vs. Diffuse Reflection (22 seconds)

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 47. Consider the following object in front of a plane mirror. Construct a ray diagram to show how light tavels from the object (arrow) to the mirror and ultimately to the eye; then indicate the portion of the mirror needed in order for the eye to view the image.

Ray Diagrams for Plane Mirrors (11 seconds)

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48. In the diagrams below, construct refracted rays to indicate the direction which the light rays bend upon crossing the boundary.
 If light travels faster in medium 1 than in medium 2, then upon entering medium 2, the light will bend towards from the normal. If the index of refraction of medium 1 is greater than medium 2, then upon entering medium 2, the light will bend away from the normal.

The Direction of Bending (20 seconds)

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49. Construct ray diagrams to show where the images of the following objects are located. Dray in the complete image and describe its characteristics (real or virtual, enlarged or reduced in size, inverted or upright). (NOTE: review the ray diagrams for all possible objects locations for each device.)

 Concave Mirror: when the object is located between C and F, the image is an inverted real image located beyond C and magnified in size. Convex Mirrors produce upright virtual images located on the other side of the mirror which are reduced in size. Converging Lens: when the object is located beyond C, the image is an inverted real image located between C and F on the opposite side of the lens and reduced in size.

Ray Diagrams - Concave Mirrors (14 seconds) | Ray Diagrams - Convex Mirrors (8 seconds) | Converging Lenses - Ray Diagrams (15 seconds)

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