# Reflection and Mirrors Review

### Part A: Multiple Choice

1. As the angle of incidence is increased for a ray incident on a reflecting surface, the angle between the incident and reflected rays ultimately approaches what value?

 a. zero b. 45 degrees c. 90 degrees d. 180 degrees

The Law of Reflection

2. If you stand three feet in front of a plane mirror, how far away would you see yourself in the mirror?

 a. 1.5 ft b. 3.0 ft c. 6.0 ft d. 12.0 ft

Image Characteristics for Plane Mirrors

3. A concave mirror with a focal length of 10 cm creates a real image 30 cm away on its principal axis; the corresponding object is located how far from the mirror?
 a. 20.0 cm b. 15.0 cm c. 7.5 cm d. 5.0 cm

The Mirror Equation - Concave Mirrors

4. A concave mirror forms a real image at 25 cm from the mirror surface along the principal axis. If the corresponding object is at a 10 cm distance, what is the mirror's focal length?

 a. 1.4 cm b. 16.7 cm c. 12.4 cm d. 7.1 cm

The Mirror Equation - Concave Mirrors | Image Characteristics for Concave Mirrors

5. 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. 30.0 cm b. 10.0 cm c. 12.4 cm d. 6.0 cm

The Mirror Equation - Concave Mirrors | Image Characteristics for Concave Mirrors

6. If a virtual image is formed 10 cm along the principal axis from a convex mirror of focal length -15 cm, what is the object distance from the mirror?

 a. 30.0 cm b. 10.0 cm c. 6.0 cm d. 3.0 cm

Image Characteristics for Convex Mirrors | The Mirror Equation - Convex Mirrors

7. If a man's face is 30 cm in front of a concave shaving mirror creating an upright image 1.5 times as large as the object, what is the mirror's focal length?

 a. 12.0 cm b. 20.0 cm c. 70.0 cm d. 90.0 cm

The Mirror Equation - Concave Mirrors | Image Characteristics for Concave Mirrors

8. Which of the following best describes the image formed by a plane mirror?

1. virtual, inverted and enlarged
2. real, inverted and reduced
3. virtual, upright and the same size as object
4. real, upright and the same size as object

Image Characteristics for Plane Mirrors

9. Which of the following best describes the image formed by a concave mirror when the object is located somewhere between the focal point (F) and the center of curvature (C) of the mirror?

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

The Anatomy of a Curved Mirror

10. Which of the following best describes the image formed by a concave mirror when the object is at a distance further than the center of curvature (C) of the mirror?

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

Ray Diagrams - Concave Mirrors | Image Characteristics for Concave Mirrors

11. Which of the following best describes the image formed by a concave mirror when the object distance from the mirror is less than the focal point (F) distance?

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

Ray Diagrams - Concave Mirrors | Image Characteristics for Concave Mirrors

12. Which of the following best describes the image formed by a convex mirror when the object distance from the mirror is less than the absolute value of the focal point (F) distance?

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

Ray Diagrams - Convex Mirrors | Image Characteristics for Convex Mirrors

13. Use of a parabolic mirror, instead of one made of a circular arc surface, can be used to reduce the occurrence of which of the following effects?

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

Spherical Aberration

14. When the image of an object is seen in a plane mirror, the image is ____.

 a. real and upright. b. real and inverted. c. virtual and upright. d. virtual and inverted.

Image Characteristics for Plane Mirrors

15. When the image of an object is seen in a plane mirror, the distance from the mirror to the image depends on ____.

1. the wavelength of light used for viewing.
2. the distance from the object to the mirror.
3. the distance of both the observer and the object to the mirror.

Image Characteristics for Plane Mirrors | Ray Diagrams for Plane Mirrors

16. If a man wishes to use a plane mirror on a wall to view both his head and his feet as he stands in front of the mirror, the required length of the mirror ____.

1. is equal to the height of the man.
2. is equal to one half the height of the man.
3. depends on the distance the man stands from the mirror.
4. depends on both the height of the man and the distance from the man to the mirror.

What Portion of a Mirror is Required to View an Image?

17. When the image of an object is seen in a concave mirror the image will ____.

 a. always be real. b. always be virtual. c. be either real or virtual. d. will always be magnified.

Image Characteristics for Concave Mirrors

18. When the image of an object is seen in a convex mirror the image will ____.

 a. always be real. b. always be virtual. c. may be either real or virtual. d. will always be magnified.

Image Characteristics for Convex Mirrors

19. Rays of light traveling parallel to the principal axis of a concave mirror will come together ____.

 a. at the center of curvature. b. at the focal point. c. at infinity. d. at a point half way to the focal point.

Reflection of Light and Image Formation

20. Right angle mirrors produce three images of objects. Which of the following is statements is/are true of the middle image?

1. The middle image is the same size as the object.
2. The middle image is the same distance from the mirror as the object.
3. The middle image will exhibit left-right reversal relative to the object.
4. The middle image is a real image.
5. The middle image is an upright image.
6. The magnification of the middle image is -1.
7. When sighting at the middle image, light will reflect twice prior to reaching one's eye.

Right Angle Mirrors

21. Two plane mirrors are attached to form a dual mirror system with an adjustable angle. As the angle between the mirrors increases, the number of images _____.

 a. increase b. decreases c. remains the same

Other Multiple Mirror Systems

22. Which of the following statements is/are true of a virtual image?

1. Virtual images are always located behind the mirror.
2. Virtual images can be either upright or inverted.
3. Virtual images can be magnified in size, reduced in size or the same size as the object.
4. Virtual images can be formed by concave, convex and plane mirrors.
5. Virtual images are not real; thus you could never see them when sighting in a mirror.
6. Virtual images result when the reflected light rays diverge.
7. Virtual images can be projected onto a sheet of paper.

Image Characteristics for Plane Mirrors | Image Characteristics for Concave Mirrors | Image Characteristics for Convex Mirrors

23. Which of the following statements is/are true of a real image?

1. Real images are always located behind the mirror.
2. Real images can be either upright or inverted.
3. Real images can be magnified in size, reduced in size or the same size as the object.
4. Real images can be formed by concave, convex and plane mirrors.
5. Real images are not virtual; thus you could never see them when sighting in a mirror.
6. Real images result when the reflected light rays diverge.
7. Real images can be projected onto a sheet of paper.

Image Characteristics for Plane Mirrors | Image Characteristics for Concave Mirrors | Image Characteristics for Convex Mirrors

24. Which of the following situations would always result in an image which is magnified in size? (NOTE: the symbol "do" is the same as the symbol "s" and the symbol "di" is the same as " s' ".)

1. Concave mirror: di > 0 and do < di
2. Convex mirror: do > 0
3. Plane Mirror: do > 0
4. Concave Mirror: do> R
5. Concave Mirror: do< f
6. Concave Mirror: do> f and do < R

Image Characteristics for Plane Mirrors | Image Characteristics for Concave Mirrors | Image Characteristics for Convex Mirrors

25. Which of the following situations would always result in an image which is upright? (NOTE: the symbol "do" is the same as the symbol "s" and the symbol "di" is the same as " s' ".)

1. Concave mirror: di > 0 and do < di
2. Convex mirror: do > 0
3. Plane Mirror: do > 0
4. Concave Mirror: do> R
5. Concave Mirror: do< f
6. Concave Mirror: do> f and do < R

Image Characteristics for Plane Mirrors | Image Characteristics for Concave Mirrors | Image Characteristics for Convex Mirrors

26. TRUE or FALSE:

Virtual images formed by mirrors are always upright images.

 a. TRUE b. FALSE

Image Characteristics for Plane Mirrors | Image Characteristics for Concave Mirrors | Image Characteristics for Convex Mirrors

### Part B: Diagramming

27. On the diagram below, sketch the path the light ray would take as it travels.

The Law of Reflection

28. Locate the images of the objects below and state which images can be seen by the eye.

Image Characteristics for Plane Mirrors | What Portion of a Mirror is Required to View an Image?

29. Locate all of the images formed by the mirror systems below.

Right Angle Mirrors | Other Multiple Mirror Systems

 30. Consider the following object in front of a plane mirror. Construct a ray diagram to show how light travels 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

31. For the right angle mirror below, draw in the secondary (or middle) image and show how light travels from the middle image to the eye.

Right Angle Mirrors

32. 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.)

Ray Diagrams - Concave Mirrors | Ray Diagrams - Convex Mirrors | Why is an Image Formed by Plane Mirrors?

### Part C: Calculations and Explanations

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

Specular vs. Diffuse Reflection

34. Write the formulae which show the relationship between image distance, object distance and focal length, and the magnification of an object/image.

The Mirror Equation - Concave Mirrors

35. Fill in the blanks below for the problem-solving rules:

Focal lengths, object and image distances are ________ if they are on the reflective side of the mirror. Object and image heights are positive if they are ________ the principle axis.

The Mirror Equation - Concave Mirrors

36. What is the focal length of a mirror which gives an image 3 meters away when an object is placed 150 cm from it?

The Mirror Equation - Concave Mirrors

37. Where is the image located when an object is placed 60 cm from a mirror which has a focal length of 20 cm?

The Mirror Equation - Concave Mirrors

38. How far would an object need to be placed from a mirror of focal length 10 cm if it is to produce an image which is 20 cm BEHIND the mirror?

The Mirror Equation - Concave Mirrors

39. A mirror with a focal length of -100 cm is used to form an image. An object is placed 50 cm in front of the mirror.

a. Where is the image located?

b. What type of mirror is being used in this problem?

The Mirror Equation - Convex Mirrors

40. An object is placed 20 cm from a mirror of focal length 10 cm. The object is 5 cm tall. Where is the image located? How tall is the image?

The Mirror Equation - Concave Mirrors

41. A 20 cm tall object produces a 40 cm tall real image when placed in front of a curved mirror with a focal length of 50 cm. Determine the place that the object must be located to produce this image.

The Mirror Equation - Concave Mirrors

42. A mirror is used to produce a virtual image that is 5 times bigger than the object. If the focal length of the mirror is 100 cm, where will the image be located?

The Mirror Equation - Concave Mirrors