Practice Quiz 7
1) The image formed in a plane mirror is
A) at the same distance in front of the mirror as the object is in front of the mirror.
B) at a shorter distance in front of the mirror than the distance that the object is in front of the mirror.
C) at the same distance behind the mirror as the object is in front of the mirror.
D) at a shorter distance behind the mirror than the distance the object is in front of the mirror.
Answer: C
2) A ray of light strikes a plane mirror perpendicular to the mirror. What is the angle of reflection?
A) 0°
B) 90°
C) 180°
D) 360°
Answer: A
3) The perpendicular distance from the center of curvature to a spherical mirror is called
A) the center of curvature.
B) the radius of curvature.
C) the focal length.
D) twice the radius of curvature.
Answer: B
4) The principal axis is the
A) straight line drawn from the center of curvature to the mid point of the mirror.
B) straight line drawn from the center of curvature to any point of the mirror.
C) straight line joining any two points on the mirror.
D) None of the other answers given is correct.
5) John's face is 20 cm in front of a concave shaving mirror. If he observes his image to be twice as big and erect,
what is the focal length of the mirror?
A) 10 cm
B) 20 cm
C) 30 cm
D) 40 cm
Answer: D
6) The mirror on the passenger side of most newer cars is a
A) convex mirror.
B) concave mirror.
C) plane mirror.
D) None of the other answers is correct.
Answer: A
7) The inside rearview mirror in an automobile is usually a
A) concave mirror.
B) convex mirror.
C) plane mirror.
D) None of the other answers is correct.
Answer: C
8) Which of the following is a correct expression for magnification?
A) m = dO/di
B) m = -dO/di
C) m = di/dO
D) m = -di/dO
Answer: D
9) Which of the following is a correct equation for Snell's law?
A) n1/n2 = sinθ2/sinθ1
B) n1/n2 = sinθ1/sinθ2
C) n2/n1 = sinθ2/sinθ1
D) None of the other answers is correct.
Answer: A
10) The speed of light in a certain medium is 2.2 × 108 m/s. What is the index of refraction of this medium?
A) 1.0
B) 1.2
C) 1.4
D) 1.6
Answer: C
11) A 4.0-cm-tall object is placed 50.0 cm from a diverging lens of focal length 25.0 cm. What is the nature and
location of the image?
A) A real image, 4.0 cm tall, 20 cm other side of the object
B) A virtual image, 4.0 cm tall, 20 cm other side of the object
C) A virtual image, 1.3 cm tall, 16.7 cm same side as the object
D) A real image, 1.3 cm tall, 16.7 cm same side as the object
Answer: C
12) An object is placed in front of a convex mirror at a distance closer than the focal length of the mirror. The
image will appear
A) behind the mirror.
B) reversed right and left.
C) upright and reduced.
D) all of the above
Answer: C
13) The image formed by a concave mirror when the object is placed between the mirror and the focal point has the
following characteristics:
A) virtual, upright, enlarged, image distance is larger than object distance
B) virtual, upright, reduced, image distance is smaller than object distance
C) real, inverted, enlarged, image distance is larger than object distance
D) virtual, inverted, reduced, image distance is smaller than object distance
Answer: A
14) Select which statement is correct in describing the image formed by a thin lens of a real object placed in front of
the lens.
A) If the lens is convex, the image will never be virtual.
B) If the image is real, then it is also inverted.
C) If the image is real, then it is also enlarged.
D) All of the previous statements are correct.
Answer: B
15) An object is placed 10 cm from a convex lens of focal length 20 cm. What is the magnification?
A) 1.0
B) 1.5
C) 2.0
D) 2.5
Answer: C