1) The principle on which mirrors work is
A) refraction.
B) polarization.
C) dispersion.
D) reflection.
Answer: D
2) Plane mirrors produce images which
A) are always smaller than the actual object.
B) are always larger than the actual object.
C) are always the same size as the actual object.
D) could be smaller, larger, or the same size as the actual object, depending on the placement of the object.
Answer: C
3) A spherical mirror on which reflection takes place on the outer surface of the spherical shape is referred to as a
A) convex mirror.
B) concave mirror.
Answer: A
4) An object is positioned between a concave mirror's center of curvature and its focal point. The image produced by the mirror is located
A) out past the center of curvature.
B) at the center of curvature.
C) between the center of curvature and the focal point.
D) at the focal point.
Answer: A
5) If the image distance is negative, the image formed is a
A) real image.
B) virtual image.
Answer: B
6) If the absolute value of the magnification is smaller than one, then the image is
A) larger than the object.
B) the same size as the object.
C) smaller than the object.
Answer: C
7) A object is 12 cm in front of a concave mirror, and the image is 3.0 cm in front of the mirror. What is the focal length of the mirror?
A) 15 cm
B) 4.0 cm
C) 2.4 cm
D) 1.3 cm
Answer: C

8) A concave spherical mirror has a focal length of 20 cm. An object is placed 30 cm in front of the mirror on the mirror's axis. Where is the image located?
A) 12 cm behind the mirror
B) 12 cm in front of the mirror
C) 60 cm behind the mirror
D) 60 cm in front of the mirror
Answer: D
9) A 1.4 cm tall object is 4.0 cm from a concave mirror. If the image is 4.0 cm tall, how far is it from the mirror?
A) 11 cm
B) 9.4 cm
C) 1.4 cm
D) 0.090 cm
Answer: A
10) A person's face is 30 cm in front of a concave shaving mirror. If the image is an erect image 1.5 times as large as the object, what is the mirror's focal length?
A) 20 cm
B) 50 cm
C) 70 cm
D) 90 cm
Answer: D
11) An object is 14 cm in front of a convex mirror. The image is 5.8 cm behind the mirror. What is the focal length of the mirror?
A) -4.1 cm
B) -8.2 cm
C) -9.9 cm
D) -20 cm
Answer: C
12) An index of refraction less than one for a medium would imply
A) that the speed of light in the medium is the same as the speed of light in vacuum.
B) that the speed of light in the medium is greater than the speed of light in vacuum.
C) refraction is not possible.
D) reflection is not possible.
Answer: B
13) Light enters air from water. The angle of refraction will be
A) greater than the angle of incidence.
B) equal to the angle of incidence.
C) less than the angle of incidence.
Answer: A
14) Lenses that are thinner at the center than the edges are called
A) converging lenses.
B) diverging lenses.
Answer: B

15) A convex lens has focal length f. An object is placed at 2f on the axis. The image formed is located
A) at 2f.
B) between f and 2f.
C) at f.
D) between the lens and f.
Answer: A
16) A light ray in air is incident on an air to glass interface at an angle of 45° and is refracted at an angle of
30° to the normal. What is the index of refraction of the glass?
A) 1.23
B) 1.31
C) 1.41
D) 1.74
Answer: C
17) An oil layer that is 5.0 cm thick is spread smoothly and evenly over the surface of water on a windless day. What is the angle of refraction in the water for a ray of light that has an angle of incidence of 45° as it enters the oil from the air above? (The index of refraction for oil is 1.15, and for water it is 1.33.)
A) 27°
B) 32°
C) 36°
D) 39°
Answer: B
18) The critical angle for a substance is measured at 53.7°. Light enters from air at 45.0°. At what angle will it continue?
A) 34.7°
B) 45.0°
C) 53.7°
D) It will not continue, but be totally reflected.
Answer: A
19) An object is 12 cm in front of a converging lens with focal length 4 cm. Where is the image?
A) 8.0 cm behind the lens
B) 6.0 cm in front of the lens
C) 6.0 cm behind the lens
D) 4.0 cm in front of the lens
Answer: C
20) When an object is 40 m in front of a converging lens the inverted image is half the size of the object.
What is the focal length of this lens?
A) 13 cm
B) 20 cm
C) 40 cm
D) 53 cm
Answer: A
21) An object is placed at 30 cm in front of a diverging lens with a focal length of 10 cm. What is the magnification?
A) 0.25
B) -0.25
C) 0.67
D) -0.67