Question 1

An object is placed 10 cm in front of a concave mirror with a 20-cm focal length. Determine the image location (in cm).

Accepted Answer

A) −20 
B) −15 
C) −10 
D) −5 
E) 6.7 
A) −20 
B) −15 
C) −10 
D) −5 
E) 6.7 A

Question 2

If you stand closer to a concave mirror than a distance of one focal length, the image you see is

Accepted Answer

A) real and inverted. 
B) real and upright. 
C) virtual and inverted. 
D) virtual and upright. 
E) none of the above because you do not get an image. 
A) real and inverted. 
B) real and upright. 
C) virtual and inverted. 
D) virtual and upright. 
E) none of the above because you do not get an image. D

Question 3

​The angle between two plane mirrors that meet at one edge is 45°. The change in direction of a ray that strikes the first mirror at a 60° angle of incidence when that ray reflects from the second mirror is

Accepted Answer

A) ​0°. 
B) ​45°. 
C) ​90°. 
D) ​150°. 
E) ​270°. 
A) ​0°. 
B) ​45°. 
C) ​90°. 
D) ​150°. 
E) ​270°. D

Question 4

When you stand in front of a convex mirror, the image you see is

Accepted Answer

A) real and inverted. 
B) real and upright. 
C) virtual and inverted. 
D) virtual and upright. 
E) real and inverted if your distance from the mirror is greater than two focal lengths. 
A) real and inverted. 
B) real and upright. 
C) virtual and inverted. 
D) virtual and upright. 
E) real and inverted if your distance from the mirror is greater than two focal lengths.

Question 5

An object is placed 15 cm in front of a concave mirror with a focal length of 30 cm. What is the magnification?

Accepted Answer

A) 1 
B) 2 
C) 1/2 
D) 1/4 
E) −2 
A) 1 
B) 2 
C) 1/2 
D) 1/4 
E) −2

Question 6

A concave mirror has a focal length of 20 cm. What is the position (in cm) of the object if the image is upright and is two times larger than the object?

Accepted Answer

A) 30 
B) 20 
C) 10 
D) 40 
E) 60 
A) 30 
B) 20 
C) 10 
D) 40 
E) 60

Question 7

A dentist uses a concave mirror (focal length 2 cm) to examine some teeth. If the distance from the object to the mirror is 1 cm, what is the magnification of the tooth?

Accepted Answer

A) 6 
B) 1 
C) 4 
D) 2 
E) 1.5 
A) 6 
B) 1 
C) 4 
D) 2 
E) 1.5

Question 8

An object 4 cm high is placed 15 cm in front of a convex mirror with a focal length of −10 cm. What is the image position (in cm)?

Accepted Answer

A) −8 
B) −4 
C) −2 
D) −6 
E) 30 
A) −8 
B) −4 
C) −2 
D) −6 
E) 30

Question 9

A convex mirror has a focal length of −20 cm. What is the object distance if the image distance is −10 cm?

Accepted Answer

A) 10 cm 
B) 40 cm 
C) 60 cm 
D) 20 cm 
E) 30 cm 
A) 10 cm 
B) 40 cm 
C) 60 cm 
D) 20 cm 
E) 30 cm

Question 10

A concave mirror with a radius of curvature of 1.0 m is illuminated by a candle located on the symmetry axis 3.0 m from the mirror. Where is the image of the candle?

Accepted Answer

60 cm in f

Question 11

An object 15 cm high is placed 15 cm in front of a convex mirror with a focal length of −10 cm. What is the image height (in cm)?

Accepted Answer

A) 2 
B) 4 
C) 6 
D) 8 
E) 30 
A) 2 
B) 4 
C) 6 
D) 8 
E) 30

Question 12

A concave mirror has a focal length of 20 cm. What is the magnification if the object and image distances are 10 cm and −20 cm, respectively?

Accepted Answer

A) 1 
B) 2 
C) 1/2 
D) 1/4 
E) −1/2 
A) 1 
B) 2 
C) 1/2 
D) 1/4 
E) −1/2

Question 13

A concave mirror has a focal length of 20 cm. What is the position (in cm) of the resulting image if the image is inverted and four times smaller than the object?

Accepted Answer

A) 15 
B) 25 
C) 50 
D) 100 
E) −15 
A) 15 
B) 25 
C) 50 
D) 100 
E) −15

Question 14

​Two flat rectangular mirrors are set edge to edge and placed perpendicular to a flat nonreflecting surface. The edges of the two mirrors meet at a 30° angle. A light ray that approaches mirror 1 is parallel to mirror 2. The angle of reflection of that ray from mirror 1 is

Accepted Answer

A) ​0°. 
B) ​30°. 
C) ​60°. 
D) ​90°. 
E) ​120°. 
A) ​0°. 
B) ​30°. 
C) ​60°. 
D) ​90°. 
E) ​120°.

Question 15

A concave mirror has a focal length of 20 cm. What is the magnification if the object's distance is 100 cm?

Accepted Answer

A) 1/2 
B) 1/4 
C) −2 
D) 4 
E) −1/4 
A) 1/2 
B) 1/4 
C) −2 
D) 4 
E) −1/4

Question 16

A clown 2 m tall looks at himself in a full-length mirror (floor-to-ceiling). Where in the mirror must he look to see his feet?

Accepted Answer

A) 1 m from the floor 
B) 50 cm from the floor 
C) 25 cm from the floor 
D) at the bottom of the mirror 
E) 1.5 m from the floor 
A) 1 m from the floor 
B) 50 cm from the floor 
C) 25 cm from the floor 
D) at the bottom of the mirror 
E) 1.5 m from the floor

Question 17

​Two flat rectangular mirrors are set edge to edge and placed perpendicular to a flat nonreflecting surface. The edges of the two mirrors meet at a 30° angle. A light ray that enters parallel to mirror 2 reflects from mirror 1 and then from mirror 2. The angle of reflection of that ray from mirror 2 is

Accepted Answer

A) ​0°. 
B) 30°. 
C) ​60°. 
D) ​90°. 
E) ​120°. 
A) ​0°. 
B) 30°. 
C) ​60°. 
D) ​90°. 
E) ​120°.

Question 18

A magician can make a candle look as if it is burning under water by focusing light from a candle flame burning in air directly on top of an underwater candle. To do this you want to use a (Hint: eliminate those that cannot work.)

Accepted Answer

A) concave mirror farther than one focal length from the burning candle. 
B) a convex mirror farther than one focal length from the burning candle. 
C) a biconcave lens farther than one focal length from the burning candle. 
D) a concave mirror closer than one focal length to the burning candle. 
E) a convex lens closer than one focal length to the burning candle. 
A) concave mirror farther than one focal length from the burning candle. 
B) a convex mirror farther than one focal length from the burning candle. 
C) a biconcave lens farther than one focal length from the burning candle. 
D) a concave mirror closer than one focal length to the burning candle. 
E) a convex lens closer than one focal length to the burning candle.

Question 19

A concave mirror has a radius of curvature of 1.0 m. An object is placed 2.0 m in front of the mirror. Determine the location of the image (in cm).

Accepted Answer

A) 130 
B) 83 
C) 67 
D) 150 
E) 200 
A) 130 
B) 83 
C) 67 
D) 150 
E) 200

Question 20

A convex mirror has a focal length of −20 cm. What is the position of the resulting image (in cm) if the image is upright and four times smaller than the object?

Accepted Answer

A) −100 
B) −25 
C) −50 
D) −15 
E) −10 
A) −100 
B) −25 
C) −50 
D) −15 
E) −10

Exam 37: Reflection and Images Formed by Reflection

An object is placed 10 cm in front of a concave mirror with a 20-cm focal length. Determine the image location (in cm).

If you stand closer to a concave mirror than a distance of one focal length, the image you see is

​The angle between two plane mirrors that meet at one edge is 45°. The change in direction of a ray that strikes the first mirror at a 60° angle of incidence when that ray reflects from the second mirror is

When you stand in front of a convex mirror, the image you see is

An object is placed 15 cm in front of a concave mirror with a focal length of 30 cm. What is the magnification?

A concave mirror has a focal length of 20 cm. What is the position (in cm) of the object if the image is upright and is two times larger than the object?

A dentist uses a concave mirror (focal length 2 cm) to examine some teeth. If the distance from the object to the mirror is 1 cm, what is the magnification of the tooth?

An object 4 cm high is placed 15 cm in front of a convex mirror with a focal length of −10 cm. What is the image position (in cm)?

A convex mirror has a focal length of −20 cm. What is the object distance if the image distance is −10 cm?

A concave mirror with a radius of curvature of 1.0 m is illuminated by a candle located on the symmetry axis 3.0 m from the mirror. Where is the image of the candle?

An object 15 cm high is placed 15 cm in front of a convex mirror with a focal length of −10 cm. What is the image height (in cm)?

A concave mirror has a focal length of 20 cm. What is the magnification if the object and image distances are 10 cm and −20 cm, respectively?

A concave mirror has a focal length of 20 cm. What is the position (in cm) of the resulting image if the image is inverted and four times smaller than the object?

​Two flat rectangular mirrors are set edge to edge and placed perpendicular to a flat nonreflecting surface. The edges of the two mirrors meet at a 30° angle. A light ray that approaches mirror 1 is parallel to mirror 2. The angle of reflection of that ray from mirror 1 is

A concave mirror has a focal length of 20 cm. What is the magnification if the object's distance is 100 cm?

A clown 2 m tall looks at himself in a full-length mirror (floor-to-ceiling). Where in the mirror must he look to see his feet?

A magician can make a candle look as if it is burning under water by focusing light from a candle flame burning in air directly on top of an underwater candle. To do this you want to use a (Hint: eliminate those that cannot work.)

A concave mirror has a radius of curvature of 1.0 m. An object is placed 2.0 m in front of the mirror. Determine the location of the image (in cm).

A convex mirror has a focal length of −20 cm. What is the position of the resulting image (in cm) if the image is upright and four times smaller than the object?

Getting Started

One-Dimensional Motion

Vectors

Two- and Three-Dimensional Motion

Newtons Laws of Motion

Applications of Newtons Laws of Motion

Gravity

Conservation of Energy

Energy in Nonisolated Systems

Systems of Particles and Conservation of Momentum

Collisions

Rotation I: Kinematics and Dynamics

Rotation II: a Conservation Approach

Static Equilibrium, Elasticity, and Fracture

Fluids

Oscillations

Traveling Waves

Superposition and Standing Waves

Temperature, Thermal Expansion, and Gas Laws

Kinetic Theory of Gases

Heat and the First Law of Thermodynamics

Entropy and the Second Law of Thermodynamics

Electric Forces

Electric Fields

Gausss Law

Electric Potential

Capacitors and Batteries

Current and Resistance

Direct Current Dc Circuits

Magnetic Fields and Forces

Gausss Law for Magnetism and Amperes Law

Faradays Law of Induction

Inductors and Ac Circuits

Maxwells Equations and Electromagnetic Waves

Diffraction and Interference

Applications of the Wave Model

Refraction and Images Formed by Refraction

Relativity

Filters

The angle between two plane mirrors that meet at one edge is 45°. The change in direction of a ray that strikes the first mirror at a 60° angle of incidence when that ray reflects from the second mirror is

Two flat rectangular mirrors are set edge to edge and placed perpendicular to a flat nonreflecting surface. The edges of the two mirrors meet at a 30° angle. A light ray that approaches mirror 1 is parallel to mirror 2. The angle of reflection of that ray from mirror 1 is