Question 1

If a reflected ray in air at an angle of reflection of 60° is totally polarized, what is the index of refraction of the reflecting material?

Accepted Answer

A)  1.50 
B)  2.00 
C)  1.73 
D)  1.15 
E)  this angle is not possible for an incident ray in air 
A)  1.50 
B)  2.00 
C)  1.73 
D)  1.15 
E)  this angle is not possible for an incident ray in air

Question 2

Which of these statements is true for the image formed by a spherical mirror?

Accepted Answer

A)  Real images are always inverted. 
B)  Virtual images of real objects are always in front of the mirror. 
C)  Virtual images of real objects are always upright. 
D)  Real images are always behind the mirror. 
A)  Real images are always inverted. 
B)  Virtual images of real objects are always in front of the mirror. 
C)  Virtual images of real objects are always upright. 
D)  Real images are always behind the mirror.

Question 3

A laser beam reflected from a horizontal glass surface is found to be totally polarized when the angle of incidence of the beam is 57 degrees. What is the angle of refraction of the transmitted beam in this case?

Accepted Answer

A)  29° 
B)  43° 
C)  33° 
D)  40° 
A)  29° 
B)  43° 
C)  33° 
D)  40°

Question 4

When light is totally polarized by reflection at an interface between two materials where the index of refraction for the incident medium is n1 and for the other is n2, the incident angle is given by θ = tan-1(n2/n1). This equation holds

Accepted Answer

A)  only when n2 > n1. 
B)  only when n1 > n2. 
C)  only when n2 > n1 + 1. 
D)  only when n2 1 + 1. 
E)  for all values of n1 and n2. 
A)  only when n2 > n1. 
B)  only when n1 > n2. 
C)  only when n2 > n1 + 1. 
D)  only when n2 1 + 1. 
E)  for all values of n1 and n2.

Question 5

A light ray reflects from a surface. If the angle of incidence is 24°, what is the angle that the reflected ray makes with the surface?

Accepted Answer

A)  24° 
B)  12° 
C)  66° 
D)  48° 
E)  102° 
A)  24° 
B)  12° 
C)  66° 
D)  48° 
E)  102°

Question 6

A light ray in air strikes a glass surface with an angle of incidence of 30.0°. The angle of refraction in the glass is 20.0°. What is the speed of light in the glass?

Accepted Answer

A)  3.00 × 108 m/s 
B)  2.50 × 108 m/s 
C)  2.33 × 108 m/s 
D)  2.05 × 108 m/s 
E)  1.50 × 108 m/s 
A)  3.00 × 108 m/s 
B)  2.50 × 108 m/s 
C)  2.33 × 108 m/s 
D)  2.05 × 108 m/s 
E)  1.50 × 108 m/s

Question 7

When a light ray meets an interface between two media, how does the angle of refraction (assuming there is a transmitted ray) compare to the angle of incidence?

Accepted Answer

A)  The angle of refraction is always less than the angle of incidence. 
B)  The angle of refraction is always greater than the angle of incidence. 
C)  It may be greater than, equal to, or less than the angle of incidence. 
D)  The angles are equal. 
A)  The angle of refraction is always less than the angle of incidence. 
B)  The angle of refraction is always greater than the angle of incidence. 
C)  It may be greater than, equal to, or less than the angle of incidence. 
D)  The angles are equal.

Question 8

How does Brewster's angle for a given interface compare to the critical angle for total internal reflection from the same surface (assuming n2 < n1, so that total internal reflection is possible)?

Accepted Answer

A)  Brewster's angle is always greater than the critical angle. 
B)  Brewster's angle can be either greater than or less than the critical angle. 
C)  Brewster's angle is always less than the critical angle. 
D)  The two angles are always equal. 
A)  Brewster's angle is always greater than the critical angle. 
B)  Brewster's angle can be either greater than or less than the critical angle. 
C)  Brewster's angle is always less than the critical angle. 
D)  The two angles are always equal.

Question 9

A thin lens of focal length −12.5 cm has a 5.0 cm tall object placed 10 cm in front of it. Where is the image located?

Accepted Answer

A)  2.5 cm behind the lens 
B)  5.6 cm behind the lens 
C)  5.6 cm in front of the lens 
D)  50 cm behind the lens 
E)  50 cm in front of the lens 
A)  2.5 cm behind the lens 
B)  5.6 cm behind the lens 
C)  5.6 cm in front of the lens 
D)  50 cm behind the lens 
E)  50 cm in front of the lens

Question 10

It is found that at a laser bounced off the surface of a liquefied gas is completely polarized when the angle of incidence of the laser beam is 45.70 degrees from the vertical. What is the index of refraction of this material?

Accepted Answer

A)  1.43 
B)  1.397 
C)  1.412 
D)  1.091 
E)  1.025 
A)  1.43 
B)  1.397 
C)  1.412 
D)  1.091 
E)  1.025

Question 11

A point-like object is placed at the focal point of a converging lens, so the light rays emerging from the lens will be parallel to the principal axis. The object is now moved closer to the lens. Which statement is true about the light rays from the lens?

Accepted Answer

A)  They will remain parallel to the principal axis. 
B)  They converge toward each other. 
C)  They emerge parallel to each other but not to the principal axis. 
D)  They diverge from each other. 
A)  They will remain parallel to the principal axis. 
B)  They converge toward each other. 
C)  They emerge parallel to each other but not to the principal axis. 
D)  They diverge from each other.

Question 12

A 6.0 cm tall object is placed 20 cm in front of a convex mirror with focal length −100 cm. Which of the following describes the image?

Accepted Answer

A)  real and inverted 
B)  real and upright 
C)  virtual and inverted 
D)  virtual and upright 
E)  not possible to determine 
A)  real and inverted 
B)  real and upright 
C)  virtual and inverted 
D)  virtual and upright 
E)  not possible to determine

Question 13

At what angle above the horizon would the sun appear if its reflected light from a lake, viewed at the same time, were completely polarized? (nwater = 1.333)

Accepted Answer

A)  53.12° 
B)  36.88° 
C)  48.75° 
D)  41.25° 
E)  23.52° 
A)  53.12° 
B)  36.88° 
C)  48.75° 
D)  41.25° 
E)  23.52°

Question 14

As you walk at 1.5 m/s toward a mirrored wall in a department store, how fast are approaching your image?

Accepted Answer

A)  1.5 m/s 
B)  3.0 m/s 
C)  6.0 m/s 
D)  0.75 m/s 
E)  0.0 the image stays at a constant distance 
A)  1.5 m/s 
B)  3.0 m/s 
C)  6.0 m/s 
D)  0.75 m/s 
E)  0.0 the image stays at a constant distance

Question 15

A lens of focal length f is used to project an image of a solar eclipse onto a flat sheet of paper. To get the clearest image, how far from the lens should be paper be?

Accepted Answer

A)  f/2 
B)  f 
C)  2f 
D)  more than 10f 
E)  less than f/10 
A)  f/2 
B)  f 
C)  2f 
D)  more than 10f 
E)  less than f/10

Question 16

A fish looking straight upward spots a berry on a tree branch above the surface of a pond. The fish is at rest 15 cm below the surface, while the berry is positioned 1.5 m above the surface. The index of refraction of water is 1.33. How far away does the berry appear to be from the fish's perspective?

Accepted Answer

A)  2.15 m 
B)  2.0 m 
C)  1.65 m 
D)  1.5 m 
A)  2.15 m 
B)  2.0 m 
C)  1.65 m 
D)  1.5 m

Question 17

When a light ray in water (n = 1.33) enters glass with index of refraction 1.60, what is the greatest angle of refraction that can occur?

Accepted Answer

A)  90.0° 
B)  56.2° 
C)  52.2° 
D)  38.7° 
E)  0.0° 
A)  90.0° 
B)  56.2° 
C)  52.2° 
D)  38.7° 
E)  0.0°

Question 18

A 9.0 cm object is placed in front of a mirror and the image formed is upright, behind the mirror, and 3.0 cm in size. Which of the following statements is true?

Accepted Answer

A)  the magnification is 1/3 and the image is real 
B)  the magnification is −1/3 and the image is real 
C)  the magnification is 1/3 and the image is virtual 
D)  the magnification is −1/3 and the image is virtual 
A)  the magnification is 1/3 and the image is real 
B)  the magnification is −1/3 and the image is real 
C)  the magnification is 1/3 and the image is virtual 
D)  the magnification is −1/3 and the image is virtual

Question 19

A ray of light enters a pane of glass with an angle of incidence of 37°. The index of refraction of the glass is 1.48. What is the angle of refraction as the ray emerges from the other side of the pane after traveling through the glass?

Accepted Answer

A)  21° 
B)  24° 
C)  53° 
D)  37° 
E)  16° 
A)  21° 
B)  24° 
C)  53° 
D)  37° 
E)  16°

Question 20

A small object is encased in an acrylic block (n = 1.5). The object appears to be 4.0 cm below the surface. What is the actual distance of the object below the surface?

Accepted Answer

A)  2.0 cm 
B)  2.7 cm 
C)  4.0 cm 
D)  5.5 cm 
E)  6.0 cm 
A)  2.0 cm 
B)  2.7 cm 
C)  4.0 cm 
D)  5.5 cm 
E)  6.0 cm

Exam 23: Reflection and Refraction of Light

If a reflected ray in air at an angle of reflection of 60° is totally polarized, what is the index of refraction of the reflecting material?

Which of these statements is true for the image formed by a spherical mirror?

A laser beam reflected from a horizontal glass surface is found to be totally polarized when the angle of incidence of the beam is 57 degrees. What is the angle of refraction of the transmitted beam in this case?

When light is totally polarized by reflection at an interface between two materials where the index of refraction for the incident medium is n1 and for the other is n2, the incident angle is given by θ = tan-1(n2/n1). This equation holds

A light ray reflects from a surface. If the angle of incidence is 24°, what is the angle that the reflected ray makes with the surface?

A light ray in air strikes a glass surface with an angle of incidence of 30.0°. The angle of refraction in the glass is 20.0°. What is the speed of light in the glass?

When a light ray meets an interface between two media, how does the angle of refraction (assuming there is a transmitted ray) compare to the angle of incidence?

How does Brewster's angle for a given interface compare to the critical angle for total internal reflection from the same surface (assuming n2 < n1, so that total internal reflection is possible)?

A thin lens of focal length −12.5 cm has a 5.0 cm tall object placed 10 cm in front of it. Where is the image located?

It is found that at a laser bounced off the surface of a liquefied gas is completely polarized when the angle of incidence of the laser beam is 45.70 degrees from the vertical. What is the index of refraction of this material?

A point-like object is placed at the focal point of a converging lens, so the light rays emerging from the lens will be parallel to the principal axis. The object is now moved closer to the lens. Which statement is true about the light rays from the lens?

A 6.0 cm tall object is placed 20 cm in front of a convex mirror with focal length −100 cm. Which of the following describes the image?

At what angle above the horizon would the sun appear if its reflected light from a lake, viewed at the same time, were completely polarized? (nwater = 1.333)

As you walk at 1.5 m/s toward a mirrored wall in a department store, how fast are approaching your image?

A lens of focal length f is used to project an image of a solar eclipse onto a flat sheet of paper. To get the clearest image, how far from the lens should be paper be?

When a light ray in water (n = 1.33) enters glass with index of refraction 1.60, what is the greatest angle of refraction that can occur?

A 9.0 cm object is placed in front of a mirror and the image formed is upright, behind the mirror, and 3.0 cm in size. Which of the following statements is true?

A ray of light enters a pane of glass with an angle of incidence of 37°. The index of refraction of the glass is 1.48. What is the angle of refraction as the ray emerges from the other side of the pane after traveling through the glass?

A small object is encased in an acrylic block (n = 1.5). The object appears to be 4.0 cm below the surface. What is the actual distance of the object below the surface?

Introduction

Motion Along a Line

Motion in a Plane

Force and Newtons Laws of Motion

Circular Motion

Conservation of Energy

Linear Momentum

Torque and Angular Momentum

Fluids

Elasticity and Oscillations

Waves

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Temperature and the Ideal Gas

Heat

Thermodynamics

Electric Forces and Fields

Electric Potential

Electric Current and Circuits

Magnetic Forces and Fields

Electromagnetic Induction

Alternating Current

Electromagnetic Waves

Optical Instruments

Interference and Diffraction

Relativity

Early Quantum Physics and the Photon

Quantum Physics

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Particle Physics

Filters

When light is totally polarized by reflection at an interface between two materials where the index of refraction for the incident medium is n₁ and for the other is n₂, the incident angle is given by θ = tan^-1(n₂/n₁). This equation holds

At what angle above the horizon would the sun appear if its reflected light from a lake, viewed at the same time, were completely polarized? (n_water = 1.333)