Question 1

A concave spherical mirror has a focal length of magnitude 20 cm. An object is placed 10 cm in front of the mirror on the mirror's axis. Where is the image located?

Accepted Answer

A)  20 cm in front of the mirror 
B)  6.7 cm in front of the mirror 
C)  20 cm behind the mirror 
D)  6.7 cm behind the mirror 
A)  20 cm in front of the mirror 
B)  6.7 cm in front of the mirror 
C)  20 cm behind the mirror 
D)  6.7 cm behind the mirror

Question 2

Which of the following terms describe lenses that are thinner at the center than at the edges? (There could be more than one correct choice.)

Accepted Answer

A)  converging lenses 
B)  convex lenses 
C)  diverging lenses 
D)  concave lenses 
A)  converging lenses 
B)  convex lenses 
C)  diverging lenses 
D)  concave lenses

Question 3

A 1.4-cm tall flower is 4.0 cm from a spherical concave mirror. If the image of the flower is 4.0 cm tall, how far is the image from the mirror?

Accepted Answer

A)  11 cm 
B)  0.090 cm 
C)  1.4 cm 
D)  9.4 cm 
A)  11 cm 
B)  0.090 cm 
C)  1.4 cm 
D)  9.4 cm

Question 4

The index of refraction of a certain glass is measured to be 1.5. What is the speed of light in that glass? $\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$

Accepted Answer

A)  $1.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
B)  $5.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
C)  $4.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
D)  $3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
E)  $2.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
A)  $1.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
B)  $5.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
C)  $4.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
D)  $3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ 
E)  $2.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$

Question 5

A 3.0-cm tall statue is 48 cm in front of a convex lens having a focal length of magnitude
20 cm.
(a) Is the image of the statue real or virtual?
(b) How far is the image from the lens?
(c) Is the image upright or inverted?
(d) How tall is the image?

Accepted Answer

(a) real (

Question 6

An object is in front of a concave spherical mirror, and its image is 4.0 cm behind the mirror. If the focal length of the mirror has a magnitude of 5.0 cm, where is the object?

Accepted Answer

A)  9.0 cm in front of the mirror 
B)  1.0 cm behind the mirror 
C)  2.2 cm in front of the mirror 
D)  2.2 cm behind the mirror 
A)  9.0 cm in front of the mirror 
B)  1.0 cm behind the mirror 
C)  2.2 cm in front of the mirror 
D)  2.2 cm behind the mirror

Question 7

When a person stands 40 cm in front of a cosmetic (concave) spherical mirror, the upright image is twice the size of the object. What is the focal length of the mirror?

Accepted Answer

A)  80 cm 
B)  40 cm 
C)  27 cm 
D)  160 cm 
A)  80 cm 
B)  40 cm 
C)  27 cm 
D)  160 cm

Question 8

An object is placed 10 cm from a convex lens with a focal length of magnitude 20 cm. What is the magnification?

Accepted Answer

A)  2.0 
B)  -2.0 
C)  1.5 
D)  0.50 
E)  -2.5 
A)  2.0 
B)  -2.0 
C)  1.5 
D)  0.50 
E)  -2.5

Question 9

A beam of light in air enters a glass slab with an index of refraction of $1.40$ at an angle of incidence of $30.0 ^ { \circ }$. What is the angle of refraction?

Accepted Answer

A)  $14.9 ^ { \circ }$ 
B)  $51.8 ^ { \circ }$ 
C)  $30.0 ^ { \circ }$ 
D)  $47.5 ^ { \circ }$ 
E)  $20.9 ^ { \circ }$ 
A)  $14.9 ^ { \circ }$ 
B)  $51.8 ^ { \circ }$ 
C)  $30.0 ^ { \circ }$ 
D)  $47.5 ^ { \circ }$ 
E)  $20.9 ^ { \circ }$

Question 10

The figure (which is exaggerated somewhat for clarity) illustrates a thin lens. This lens is made of a material with an index of refraction of 1.48, and has radii of magnitudes 6.0 cm and 4.0 cm. What
Is the focal length of the lens?

Accepted Answer

A)  $+ 25 m$ 
B)  $- 25 \mathrm {~cm}$ 
C)  $- 4.0 \mathrm {~m}$ 
D)  $+ 5.0 \mathrm {~m}$ 
E)  $- 5.0 \mathrm {~cm}$ 
A)  $+ 25 m$ 
B)  $- 25 \mathrm {~cm}$ 
C)  $- 4.0 \mathrm {~m}$ 
D)  $+ 5.0 \mathrm {~m}$ 
E)  $- 5.0 \mathrm {~cm}$

Question 11

Suppose you place an object in front of a concave mirror. Which of the following statements must be true? (There could be more than one correct choice.)

Accepted Answer

A)  If you position the object between the mirror and the focal point of the mirror, its image must be upright and virtual. 
B)  No matter where you place the object, a real image of the object will be formed. 
C)  The image of the object will always be smaller than the object. 
D)  The image of the object will always be inverted. 
E)  No matter where you place the object, the image of the object will always be virtual and upright. 
A)  If you position the object between the mirror and the focal point of the mirror, its image must be upright and virtual. 
B)  No matter where you place the object, a real image of the object will be formed. 
C)  The image of the object will always be smaller than the object. 
D)  The image of the object will always be inverted. 
E)  No matter where you place the object, the image of the object will always be virtual and upright.

Question 12

Which of the following terms describe lenses that are thicker at the center than at the edges? (There could be more than one correct choice.)

Accepted Answer

A)  converging lenses 
B)  convex lenses 
C)  concave lenses 
D)  diverging lenses 
A)  converging lenses 
B)  convex lenses 
C)  concave lenses 
D)  diverging lenses

Question 13

Suppose you wanted to start a fire using a mirror to focus sunlight. Which of the following statements is most accurate?

Accepted Answer

A)  It would be best to use a convex mirror. 
B)  One cannot start a fire using a mirror, since mirrors form only virtual images. 
C)  It would be best to use a plane mirror. 
D)  It would be best to use a concave mirror, with the object to be ignited positioned halfway between the mirror and its center of curvature. 
E)  It would be best to use a concave mirror, with the object to be ignited positioned at the center of curvature of the mirror. 
A)  It would be best to use a convex mirror. 
B)  One cannot start a fire using a mirror, since mirrors form only virtual images. 
C)  It would be best to use a plane mirror. 
D)  It would be best to use a concave mirror, with the object to be ignited positioned halfway between the mirror and its center of curvature. 
E)  It would be best to use a concave mirror, with the object to be ignited positioned at the center of curvature of the mirror.

Question 14

A thin lens projects an image of a man as shown in the figure. Rays marked A, B, and C travel to the lens from the man's ear. Draw the paths of these three rays after they have passed through the lens. Note that $\mathrm { A }$ is parallel to the principal axis, B goes through the center of the lens, C goes through the focal point on the left, and the point marked $f$ is the focal point on the right of the lens.

Accepted Answer

The answer of A thin lens projects an image of...

Question 15

The critical angle for a substance in air is measured at $53.7 ^ { \circ }$. If light enters this substance from air at $45.0 ^ { \circ }$ with the normal, at what angle with the normal will it continue to travel?

Accepted Answer

A)  $34.7 ^ { \circ }$ 
B)  $53.7 ^ { \circ }$ 
C)  $45.0 ^ { \circ }$ 
D)  It will not continue, but will be totally reflected. 
A)  $34.7 ^ { \circ }$ 
B)  $53.7 ^ { \circ }$ 
C)  $45.0 ^ { \circ }$ 
D)  It will not continue, but will be totally reflected.

Question 16

An optic fiber is made of clear plastic with an index of refraction of $1.50$. For what range of angles of incidence $\theta$ with the lateral surface of the fiber will light remain inside the plastic "guide" if it is surrounded by air?

Accepted Answer

A)  $23.4 ^ { \circ } < \theta < 90 ^ { \circ }$ 
B)  $41.8 ^ { \circ } < \theta < 90 ^ { \circ }$ 
C)  $38.3 ^ { \circ } < \theta < 90 ^ { \circ }$ 
D)  $21.1 ^ { \circ } < \theta < 90 ^ { \circ }$ 
E)  $40.3 ^ { \circ } < \theta < 90 ^ { \circ }$ 
A)  $23.4 ^ { \circ } < \theta < 90 ^ { \circ }$ 
B)  $41.8 ^ { \circ } < \theta < 90 ^ { \circ }$ 
C)  $38.3 ^ { \circ } < \theta < 90 ^ { \circ }$ 
D)  $21.1 ^ { \circ } < \theta < 90 ^ { \circ }$ 
E)  $40.3 ^ { \circ } < \theta < 90 ^ { \circ }$

Question 17

Light enters glass from air. The angle of refraction will be

Accepted Answer

A)  equal to the angle of incidence. 
B)  less than the angle of incidence. 
C)  greater than the angle of incidence. 
A)  equal to the angle of incidence. 
B)  less than the angle of incidence. 
C)  greater than the angle of incidence.

Question 18

Light enters air from water. The angle of refraction will be

Accepted Answer

A)  less than the angle of incidence. 
B)  greater than the angle of incidence. 
C)  equal to the angle of incidence. 
A)  less than the angle of incidence. 
B)  greater than the angle of incidence. 
C)  equal to the angle of incidence.

Question 19

Which one of the following numbers is the correct magnification produced by a plane mirror?

Accepted Answer

A)  3/2 
B)  1/2 
C)  2 
D)  1 
E)  1/4 
A)  3/2 
B)  1/2 
C)  2 
D)  1 
E)  1/4

Question 20

An object that is 4.00 cm tall is placed 18.0 cm in front of a concave mirror having a focal length of 20.0 cm. What is the location of its image in relation to the mirror and what are its characteristics?

Accepted Answer

A)  20 cm on the same side of mirror, real, 10.0 times bigger 
B)  18 cm on the same side of mirror, virtual, 2.25 times bigger 
C)  180 cm on the other side of mirror, virtual, 10.0 times bigger 
D)  10 cm on the other side of mirror, virtual, 10.0 times bigger 
E)  180 cm on the other side of mirror, real, 6.00 times bigger 
A)  20 cm on the same side of mirror, real, 10.0 times bigger 
B)  18 cm on the same side of mirror, virtual, 2.25 times bigger 
C)  180 cm on the other side of mirror, virtual, 10.0 times bigger 
D)  10 cm on the other side of mirror, virtual, 10.0 times bigger 
E)  180 cm on the other side of mirror, real, 6.00 times bigger

Exam 22: Electromagnetic Waves

A concave spherical mirror has a focal length of magnitude 20 cm. An object is placed 10 cm in front of the mirror on the mirror's axis. Where is the image located?

Which of the following terms describe lenses that are thinner at the center than at the edges? (There could be more than one correct choice.)

A 1.4-cm tall flower is 4.0 cm from a spherical concave mirror. If the image of the flower is 4.0 cm tall, how far is the image from the mirror?

The index of refraction of a certain glass is measured to be 1.5. What is the speed of light in that glass? (c=3.0×108 m/s)\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)(c=3.0×108 m/s)

A 3.0-cm tall statue is 48 cm in front of a convex lens having a focal length of magnitude 20 cm. (a) Is the image of the statue real or virtual? (b) How far is the image from the lens? (c) Is the image upright or inverted? (d) How tall is the image?

An object is in front of a concave spherical mirror, and its image is 4.0 cm behind the mirror. If the focal length of the mirror has a magnitude of 5.0 cm, where is the object?

When a person stands 40 cm in front of a cosmetic (concave) spherical mirror, the upright image is twice the size of the object. What is the focal length of the mirror?

An object is placed 10 cm from a convex lens with a focal length of magnitude 20 cm. What is the magnification?

A beam of light in air enters a glass slab with an index of refraction of 1.401.401.40 at an angle of incidence of 30.0∘30.0 ^ { \circ }30.0∘ . What is the angle of refraction?

The figure (which is exaggerated somewhat for clarity) illustrates a thin lens. This lens is made of a material with an index of refraction of 1.48, and has radii of magnitudes 6.0 cm and 4.0 cm. What Is the focal length of the lens?

Suppose you place an object in front of a concave mirror. Which of the following statements must be true? (There could be more than one correct choice.)

Which of the following terms describe lenses that are thicker at the center than at the edges? (There could be more than one correct choice.)

Suppose you wanted to start a fire using a mirror to focus sunlight. Which of the following statements is most accurate?

The critical angle for a substance in air is measured at 53.7∘53.7 ^ { \circ }53.7∘ . If light enters this substance from air at 45.0∘45.0 ^ { \circ }45.0∘ with the normal, at what angle with the normal will it continue to travel?

An optic fiber is made of clear plastic with an index of refraction of 1.501.501.50 . For what range of angles of incidence θ\thetaθ with the lateral surface of the fiber will light remain inside the plastic "guide" if it is surrounded by air?

Light enters glass from air. The angle of refraction will be

Light enters air from water. The angle of refraction will be

Which one of the following numbers is the correct magnification produced by a plane mirror?

An object that is 4.00 cm tall is placed 18.0 cm in front of a concave mirror having a focal length of 20.0 cm. What is the location of its image in relation to the mirror and what are its characteristics?

Introduction, Measurement, Estimating

Describing Motion: Kinematics in One Dimension

Kinematics in Two Dimensions; Vectors

Dynamics: Newtons Laws of Motion

Circular Motion; Gravitation

Work and Energy

Linear Momentum

Rotational Motion

Static Equilibrium; Elasticity and Fracture

Fluids

Oscillations and Waves

Sound

Temperature and Kinetic Theory

Heat

The Laws of Thermodynamics

Electric Charge and Electric Field

Electric Potential

Electric Currents

Dc Circuits

Magnetism

Electromagnetic Induction and Faradays Law

Light: Geometric Optics

The Wave Nature of Light

Optical Instruments

The Special Theory of Relativity

Early Quantum Theory and Models of the Atom

Quantum Mechanics of Atoms

Molecules and Solids

Nuclear Physics and Radioactivity

Nuclear Energy; Effects and Uses of Radiation

Elementary Particles

Astrophysics and Cosmology

Filters

The index of refraction of a certain glass is measured to be 1.5. What is the speed of light in that glass? $\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$

A beam of light in air enters a glass slab with an index of refraction of $1.40$ at an angle of incidence of $30.0 ^ { \circ }$ . What is the angle of refraction?

The critical angle for a substance in air is measured at $53.7 ^ { \circ }$ . If light enters this substance from air at $45.0 ^ { \circ }$ with the normal, at what angle with the normal will it continue to travel?

An optic fiber is made of clear plastic with an index of refraction of $1.50$ . For what range of angles of incidence $\theta$ with the lateral surface of the fiber will light remain inside the plastic "guide" if it is surrounded by air?