Question 1

Which statement about images is correct?

Accepted Answer

A) A virtual image cannot be formed on a screen. 
B) A virtual image cannot be viewed by the unaided eye. 
C) A virtual image cannot be photographed. 
D) A real image must be erect. 
E) Mirrors always produce real images because they reflect light. 
A) A virtual image cannot be formed on a screen. 
B) A virtual image cannot be viewed by the unaided eye. 
C) A virtual image cannot be photographed. 
D) A real image must be erect. 
E) Mirrors always produce real images because they reflect light. A

Question 2

For both diverging and converging lenses,a ray parallel to the optical axis refracts through the far focal point.

Accepted Answer

A) True 
 B)False  False

Question 3

A ray in air is incident on a glass plate whose index of refraction is 1.42.The angle of refraction is one-half the angle of reflection.The angle of refraction is closest to:

Accepted Answer

A) 45° 
B) 43° 
C) 41° 
D) 39° 
E) 37° 
A) 45° 
B) 43° 
C) 41° 
D) 39° 
E) 37° A

Question 4

An object placed to the left of a lens and its focal point forms an image at d.When placed at the focal point the image is formed at infinity (d = ∞).When it is placed between the focal point and the lens it is formed at d > ∞.Explain.

Accepted Answer

d > ∞ only means the

Question 5

Situation 18.2
An erect object is 50 cm from a concave mirror of radius 60 cm.
-In Situation 18.2,the lateral magnification of the image is closest to:

Accepted Answer

A) +0.4 
B) +0.7 
C) +1.5 
D) -0.7 
E) -1.5 
A) +0.4 
B) +0.7 
C) +1.5 
D) -0.7 
E) -1.5

Question 6

A ray in glass arrives at the glass-water interface at an angle of 48° with the normal.The refracted ray,in water,makes a 62° angle with the normal.The index of refraction of water is 1.33.In the figure,the angle of incidence of a different ray in the glass is 25°.The angle of refraction in the water is closest to:

Accepted Answer

A) 57° 
B) 55° 
C) 53° 
D) 59° 
E) 61° 
A) 57° 
B) 55° 
C) 53° 
D) 59° 
E) 61°

Question 7

Situation 18.1
A tank holds a 1.44 m thick layer of oil that floats on a 0.96 m thick layer of brine.Both liquids are clear and do not intermix.Point O is at the bottom of the tank,on a vertical axis.The indices of refraction of the oil and the brine are 1.40 and 1.52,respectively.
-In Situation 18.1,a ray originating at O reaches a point on the oil-air interface at the critical angle.The distance of this point from the axis is closest to:

Accepted Answer

A) 1.5 m 
B) 1.7 m 
C) 1.9 m 
D) 2.1 m 
E) 2.3 m 
A) 1.5 m 
B) 1.7 m 
C) 1.9 m 
D) 2.1 m 
E) 2.3 m

Question 8

Two plane mirrors make an angle of 30°.A light ray enters the system and is reflected once off each mirror.Through what angle is the ray turned?

Accepted Answer

A) 60° 
B) 90° 
C) 120° 
D) 150° 
A) 60° 
B) 90° 
C) 120° 
D) 150°

Question 9

If you increase the object distance from 4 to 8,what happen to the amount of light admitted through the lens? What happens to the real image?

Accepted Answer

The lens gathers 1/4

Question 10

A person of height h stands in front of a plane mirror.What is the minimum length of the mirror such that he can see his entire body?

Accepted Answer

A) h 
B) h/2 
C) 2h 
D) h/4 
E) It depends on how far the person is from the mirror. 
A) h 
B) h/2 
C) 2h 
D) h/4 
E) It depends on how far the person is from the mirror.

Question 11

A tank holds a layer of oil,1.58 m thick,which floats on a layer of syrup that is 0.66 m thick.Both liquids are clear and do not intermix.A ray,which originates at the bottom of the tank on a vertical axis,crosses the oil-syrup interface at a point 0.90 m from the axis.The ray continues and arrives at the oil-air interface,2.00 m from the axis and at the critical angle.In the figure,the index of refraction of the syrup is closest to:

Accepted Answer

A) 1.24 
B) 1.17 
C) 1.66 
D) 1.52 
E) 1.37 
A) 1.24 
B) 1.17 
C) 1.66 
D) 1.52 
E) 1.37

Question 12

In general,the more strongly curved a lens's surface,the lower its index of refraction.

Accepted Answer

A) True 
 B)False

Question 13

Situation 18.2
An erect object is 50 cm from a concave mirror of radius 60 cm.
-In Situation 18.2,the character of the image is:

Accepted Answer

A) real and erect 
B) real and inverted 
C) virtual and erect 
D) virtual and inverted 
E) indeterminate 
A) real and erect 
B) real and inverted 
C) virtual and erect 
D) virtual and inverted 
E) indeterminate

Question 14

Light having a frequency in vacuum of 6.0 × 1014 Hz enters a liquid of refractive index 2.0.In this liquid,its frequency will be:

Accepted Answer

A) 12 × 1014 Hz 
B) 6.0 × 1014 Hz 
C) 3.0 × 1014 Hz 
D) 1.5 × 1014 Hz 
E) None of the above choices are correct. 
A) 12 × 1014 Hz 
B) 6.0 × 1014 Hz 
C) 3.0 × 1014 Hz 
D) 1.5 × 1014 Hz 
E) None of the above choices are correct.

Question 15

A light ray (red)enters a concentrically cladded optical fiber at its center and an angle of 29.0° to the axis of the fiber.The diameter of the fiber is 1.0 mm and its refractive index is nf = 1.35.What must be the value of ncladding to guarantee total internal reflection? (nair = 1.00)

Accepted Answer

A) 1.18 
B) 1.26 
C) 1.70 
D) 1.08 
A) 1.18 
B) 1.26 
C) 1.70 
D) 1.08

Question 16

If a lens produces a magnification of 1/4,the image is 4 times a large as the object but is inverted.

Accepted Answer

A) True 
 B)False

Question 17

The critical angle for two materials is the angle of incidence for which the incident light is not deflected as it passes from one of these materials into the other one.

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

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

Question 19

Situation 18.1
A tank holds a 1.44 m thick layer of oil that floats on a 0.96 m thick layer of brine.Both liquids are clear and do not intermix.Point O is at the bottom of the tank,on a vertical axis.The indices of refraction of the oil and the brine are 1.40 and 1.52,respectively.
-In Situation 18.1,a ray originating at O,crosses the brine-oil interface at a point 0.60 m from the axis.The ray continues and emerges into the air.The angle that the ray in the air makes with the vertical is closest to:

Accepted Answer

A) 48° 
B) 51° 
C) 54° 
D) 57° 
E) 60° 
A) 48° 
B) 51° 
C) 54° 
D) 57° 
E) 60°

Question 20

The index of refraction of the core of a piece of fiber optic cable is 1.72.If the index of the surrounding cladding is 1.41,what is the critical angle for total internal reflection for a light ray in the core incident on the core-cladding interface?

Accepted Answer

A) 55.1° 
B) 44.0° 
C) 49.6° 
D) 60.6° 
A) 55.1° 
B) 44.0° 
C) 49.6° 
D) 60.6°

Exam 18: Ray Optics

Which statement about images is correct?

For both diverging and converging lenses,a ray parallel to the optical axis refracts through the far focal point.

A ray in air is incident on a glass plate whose index of refraction is 1.42.The angle of refraction is one-half the angle of reflection.The angle of refraction is closest to:

An object placed to the left of a lens and its focal point forms an image at d.When placed at the focal point the image is formed at infinity (d = ∞).When it is placed between the focal point and the lens it is formed at d > ∞.Explain.

Situation 18.2 An erect object is 50 cm from a concave mirror of radius 60 cm. -In Situation 18.2,the lateral magnification of the image is closest to:

Two plane mirrors make an angle of 30°.A light ray enters the system and is reflected once off each mirror.Through what angle is the ray turned?

If you increase the object distance from 4 to 8,what happen to the amount of light admitted through the lens? What happens to the real image?

A person of height h stands in front of a plane mirror.What is the minimum length of the mirror such that he can see his entire body?

In general,the more strongly curved a lens's surface,the lower its index of refraction.

Situation 18.2 An erect object is 50 cm from a concave mirror of radius 60 cm. -In Situation 18.2,the character of the image is:

Light having a frequency in vacuum of 6.0 × 1014 Hz enters a liquid of refractive index 2.0.In this liquid,its frequency will be:

A light ray (red)enters a concentrically cladded optical fiber at its center and an angle of 29.0° to the axis of the fiber.The diameter of the fiber is 1.0 mm and its refractive index is nf = 1.35.What must be the value of ncladding to guarantee total internal reflection? (nair = 1.00)

If a lens produces a magnification of 1/4,the image is 4 times a large as the object but is inverted.

The critical angle for two materials is the angle of incidence for which the incident light is not deflected as it passes from one of these materials into the other one.

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

The index of refraction of the core of a piece of fiber optic cable is 1.72.If the index of the surrounding cladding is 1.41,what is the critical angle for total internal reflection for a light ray in the core incident on the core-cladding interface?

Representing Motion

Motion in One Dimension

Vectors and Motion in Two Dimensions

Forces and Newtons Laws of Motion

Applying Newtons Laws

Circular Motion,orbits,and Gravity

Rotational Motion

Equilibrium and Elasticity

Momentum

Energy and Work

Using Energy

Thermal Properties of Matter

Fluids

Oscillations

Traveling Waves and Sound

Superposition and Standing Waves

Wave Optics

Optical Instruments

Electric Fields and Forces

Electric Potential

Current and Resistance

Circuits

Magnetic Fields and Forces

Electromagnetic Induction and Electromagnetic Waves

Ac Electricity

Relativity

Quantum Physics

Atoms and Molecules

Nuclear Physics

Filters

Light having a frequency in vacuum of 6.0 × 10¹⁴ Hz enters a liquid of refractive index 2.0.In this liquid,its frequency will be:

A light ray (red)enters a concentrically cladded optical fiber at its center and an angle of 29.0° to the axis of the fiber.The diameter of the fiber is 1.0 mm and its refractive index is nf = 1.35.What must be the value of ncladding to guarantee total internal reflection? (n_air = 1.00)