Deck 23: Reflection and Refraction of Light

Question 1

A light ray reflects from a surface.If the angle of incidence is 24 $^{\circ}$ ,what is the angle between the reflected ray and the incident ray at the surface?

A) 24 $^{\circ}$
B) 12 $^{\circ}$
C) 66 $^{\circ}$
D) 48 $^{\circ}$
E) 102 $^{\circ}$

Answer 1

48 $^{\circ}$

Question 2

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) 90.0 $^{\circ}$
B) 56.2 $^{\circ}$
C) 52.2 $^{\circ}$
D) 38.7 $^{\circ}$
E) 0.0 $^{\circ}$

Answer 2

56.2 $^{\circ}$

Question 3

A light ray in air strikes a glass surface with an angle of incidence of 30.0 $^{\circ}$ .The angle of refraction in the glass is 20.0 $^{\circ}$ .What is the index of refraction of the glass?

A) 1.67
B) 1.55
C) 1.52
D) 1.46
E) 1.24

Answer 3

1.46

Question 4

A ray of light enters a pane of glass with an angle of incidence of 37 $^{\circ}$ .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?

A) 21 $^{\circ}$
B) 24 $^{\circ}$
C) 53 $^{\circ}$
D) 37 $^{\circ}$
E) 16 $^{\circ}$

Question 5

When light goes from a material with a lower index of refraction n₁ into a material with a higher index of refraction n₂ with an angle of incidence of 30.0 $^{\circ}$ ,which of the following is true?

A) the angle of refraction is more than 30.0 $^{\circ}$
B) the angle of refraction is less than 30.0 $^{\circ}$
C) total internal reflection may occur
D) the angle of refraction is more than 30.0 $^{\circ}$ and total internal reflection may occur
E) the angle of refraction is less than 30.0 $^{\circ}$ and total internal reflection may occur

Question 6

When a light ray in air enters glass with index of refraction 1.60,what is the greatest angle of refraction that can occur?

A) 90.0 $^{\circ}$
B) 56.2 $^{\circ}$
C) 52.2 $^{\circ}$
D) 38.7 $^{\circ}$
E) 0.0 $^{\circ}$

Question 7

According to Huygens' principle,every point on a wave front acts as a source of a new _________ wave.

A) transverse
B) spherical
C) longitudinal
D) sinusoidal
E) plane

Question 8

A ray of light enters an equilateral prism made of material with n = 1.45 at an angle of incidence $\theta$ . The internally refracted ray is parallel to the base of the prism.What is the angle of refraction for the ray leaving the prism?

A) 46.5 $^{\circ}$
B) 30.0 $^{\circ}$
C) 20.2 $^{\circ}$
D) 15.7 $^{\circ}$
E) the ray won't leave the prism

Question 9

Specular reflection occurs whenever

A) rays reflect from a surface.
B) rays reflect in all directions from a surface.
C) rays reflect at only one angle from a surface.
D) parallel rays reflect at the same angle from a surface.
E) visible light rays reflect.

Question 10

What is the least value for an index of refraction?

A) 0
B) 0.5
C) 1
D) just less than 1
E) (1/2)^1/2

Question 11

A light ray in material 1 goes into material 2.The angle of incidence in material 1 is 40.0 $^{\circ}$ and the angle of refraction in material 2 is 31.0 $^{\circ}$ .If the index of refraction of material 1 is 1.60,what is the index of refraction of material 2?

A) 3.20
B) 2.00
C) 1.88
D) 1.41
E) 1.20

Question 12

A diver,below the surface of a lake,notices that no light appears to be coming toward her greater than the angle $\theta$ ,measured from the vertical.If the index of refraction of water is 1.33,what is the angle $\theta$ ?

A) 30 $^{\circ}$
B) 34 $^{\circ}$
C) 37 $^{\circ}$
D) 49 $^{\circ}$
E) 54 $^{\circ}$

Question 13

A ray of light enters an equilateral prism made of material with n = 1.45.What angle of incidence, $\theta$ , will cause the internally refracted ray to be parallel to the base of the prism?

A) 46.5 $^{\circ}$
B) 30.0 $^{\circ}$
C) 20.2 $^{\circ}$
D) 5.70 $^{\circ}$
E) this cannot happen

Question 14

A light ray reflects from a surface.If the angle of incidence is 24 $^{\circ}$ ,what is the angle that the reflected ray makes with the surface?

A) 24 $^{\circ}$
B) 12 $^{\circ}$
C) 66 $^{\circ}$
D) 48 $^{\circ}$
E) 102 $^{\circ}$

Question 15

A light ray in air strikes a glass surface with an angle of incidence of 30.0 $^{\circ}$ .The angle of refraction in the glass is 20.0 $^{\circ}$ .What is the speed of light in the glass?

A) 3.00 $\times$ 10⁸ m/s
B) 2.50 $\times$ 10⁸ m/s
C) 2.33 $\times$ 10⁸ m/s
D) 2.05 $\times$ 10⁸ m/s
E) 1.50 $\times$ 10⁸ m/s

Question 16

A ray of light enters a pane of glass with an angle of incidence of 37 $^{\circ}$ .The index of refraction of the glass is 1.48.What is the angle of incidence on the far side of the pane of glass?

A) 21 $^{\circ}$
B) 24 $^{\circ}$
C) 53 $^{\circ}$
D) 37 $^{\circ}$
E) 16 $^{\circ}$

Question 17

A light ray strikes the surface of sapphire (n = 1.77 ) at an angle of incidence of 40.0 $^{\circ}$ .What angle of refraction results?

A) 21.3 $^{\circ}$
B) 50.0 $^{\circ}$
C) 59.7 $^{\circ}$
D) 57.0 $^{\circ}$
E) 17.7 $^{\circ}$

Question 18

A light ray in air strikes a glass surface with an angle of incidence of 30.0 $^{\circ}$ .The angle of refraction in the glass is 20.0 $^{\circ}$ .What is the angle between the reflected ray and the refracted ray?

A) 60 $^{\circ}$
B) 70 $^{\circ}$
C) 120 $^{\circ}$
D) 130 $^{\circ}$
E) 140 $^{\circ}$

Question 19

Which of the following best describes the greatest known value for index of refraction?

A) 1.732
B) 1.999.... (just shy of 2)
C) 2.000... (2 exactly)
D) a value greater than 2 but not greater than 3
E) a value greater than 3

Question 20

A small object is enclosed in plastic (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?

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

Question 21

A ray of light enters an equilateral prism made of material with n = 1.45.What angle of incidence, $\theta$ ,will cause the internally refracted ray to be parallel to the base of the prism?

A) 46.5 $^{\circ}$
B) 30.0 $^{\circ}$
C) 20.2 $^{\circ}$
D) 5.70 $^{\circ}$
E) this cannot happen

Question 22

A convex mirror has a radius of 10 cm.What is its focal length?

A) 10 cm
B) 5.0 cm
C) 20 cm
D) -5.0 cm
E) -10 cm

Question 23

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 $\theta$ = tan^-1(n₂/n₁).This equation holds

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

Question 24

In a camera,the image focused on the film is

A) real and upright.
B) real and inverted.
C) virtual and upright.
D) virtual and inverted.
E) technically a mirage.

Question 25

What is the critical angle for diamond (n = 2.42)?

A) 2.42 $^{\circ}$
B) 67.5 $^{\circ}$
C) 65.6 $^{\circ}$
D) 24.4 $^{\circ}$
E) 37.1 $^{\circ}$

Question 26

A ray of light enters an equilateral prism made of material with n = 1.45 at an angle of incidence $\theta$ .The internally refracted ray is parallel to the base of the prism.What is the angle of refraction for the ray leaving the prism?

A) 46.5 $^{\circ}$
B) 30.0 $^{\circ}$
C) 20.2 $^{\circ}$
D) 15.7 $^{\circ}$
E) the ray won't leave the prism

Question 27

A small object is enclosed in plastic (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?

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

Question 28

A light ray goes through two thick rectangular slabs of glass,each of the same uniform thickness.The first slab has index of refraction n₁ and the second n₂.If n₁ < n₂.How does the original angle of incidence $\theta$ _i into the first slab compare to the final angle of refraction $\theta$ _f where the ray leaves the second slab going back into air?

A) $\theta$ _i > $\theta$ _f
B) $\theta$ _i < $\theta$ _f
C) $\theta$ _i = $\theta$ _f
D) $\theta$ _i = (n₁/n₂) $\theta$ _f
E) more information is needed

Question 29

If a reflected ray in air at an angle of reflection of 60 $^{\circ}$ is totally polarized,what is the index of refraction of the reflecting material?

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 30

When light in material 1,which is in contact with material 2,undergoes total internal reflection,what condition is necessary for their indices of refraction?

A) n₁ = 2 n₂
B) n₁ > n₂
C) n₁ < n₂
D) n₁ = n₂ + 1
E) n₂ = 1.5

Question 31

When you see your image in a plane mirror,your image appears to be

A) in front of the mirror.
B) at the surface of the mirror.
C) behind the surface of the mirror at a distance equal to your distance from the mirror.
D) behind the surface of the mirror at a distance equal to half your distance from the mirror.

Question 32

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)

A) 53.12 $^{\circ}$
B) 36.88 $^{\circ}$
C) 48.75 $^{\circ}$
D) 41.25 $^{\circ}$
E) 23.52 $^{\circ}$

Question 33

The critical angle for Lucite is 41.8 $^{\circ}$ .What is Brewster's angle for Lucite?

A) 33.7 $^{\circ}$
B) 26.3 $^{\circ}$
C) 48.2 $^{\circ}$
D) 56.3 $^{\circ}$
E) Brewster's angle does not exist for this material

Question 34

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

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 35

A ray of light enters an equilateral prism made of material with n = 1.45.What angle of incidence, $\theta$ ,will cause the internally refracted ray to be parallel to the base of the prism?

A) 46.5 $^{\circ}$
B) 30.0 $^{\circ}$
C) 20.2 $^{\circ}$
D) 5.70 $^{\circ}$
E) this cannot happen

Question 36

A mirror has a focal length -20 cm.If an object is placed 10 cm in front of the mirror,where will the image form?

A) 20 cm in front of the mirror
B) 20 cm behind the mirror
C) 6.7 in from of the mirror
D) 6.7 behind the mirror
E) no image will form

Question 37

A small object is enclosed in plastic (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?

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

Question 38

A ray of light enters an equilateral prism made of material with n = 1.45 at an angle of incidence $\theta$ .The internally refracted ray is parallel to the base of the prism.What is the angle of refraction for the ray leaving the prism?

A) 46.5 $^{\circ}$
B) 30.0 $^{\circ}$
C) 20.2 $^{\circ}$
D) 15.7 $^{\circ}$
E) the ray won't leave the prism

Question 39

When total internal reflection happens at a plastic-air interface

A) half the light is refracted.
B) half the light is reflected.
C) light hits the interface from the air side.
D) light hits the interface from the plastic side.
E) the law of reflection ceases to hold.

Question 40

An optical fiber having index of refraction 1.40 is clad with a material of index of refraction 1.25.What is the critical angle for this fiber?

A) 63.2 $^{\circ}$
B) 26.8 $^{\circ}$
C) 41.8 $^{\circ}$
D) 73.0 $^{\circ}$
E) 16.5 $^{\circ}$

Question 41

An object is placed at the focal point of a converging lens and the light rays 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) the will remain parallel to the principle axis
B) they converge toward each other
C) they emerge parallel to each other but not the principle axis
D) they diverge from each other

Question 42

In order to produce an image double the size of an object with a converging lens of focal length f,what object distance should be used?

A) f
B) f/2
C) 2f
D) 2f/3
E) 3f/2

Question 43

An object is placed 60 cm in front of a mirror and the image is upright and 1/4 the size of the object.What is the focal length of the mirror?

A) -12 cm
B) -20 cm
C) -45 cm
D) -75 cm
E) some positive value not given

Question 44

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?

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 45

A thin lens of focal length 12.5 cm has a 5.0 cm tall object placed 10 cm in front of it.Where will the image be formed?

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 46

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

A) real images of real objects 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 in back of the mirror

Question 47

A thin lens of focal length -12.5 cm has a 5.0 cm tall object placed 10 cm in front of it.What are the size and orientation of the image?

A) 4.0 cm,inverted
B) 4.0 cm,upright
C) 2.8 cm,inverted
D) 2.8 cm,upright
E) 100 cm,inverted

Question 48

A building 30 m tall is being photographed with a camera with a lens of focal length 50 mm.How tall is the image on the film if the building is 100 m away?

A) 30 mm
B) 15 mm
C) 10 mm
D) 3.0 mm
E) 1.0 mm

Question 49

A 25 cm focal length mirror has a 3.0 cm tall object placed 20 cm in front of it.What is the size of the image and is it upright or inverted?

A) 1.0 cm,upright
B) 3.8 cm,inverted
C) 2.4 cm,inverted
D) 15 cm,upright
E) 12 cm,upright

Question 50

A concave mirror has an object placed 40 cm in front of it.An image forms 60 cm in front of the mirror.What is the focal length of the mirror?

A) 60 cm
B) 120 cm
C) -120 cm
D) 100 cm
E) 24 cm

Question 51

When projected through a single lens,the image of a movie on a screen is

A) real and inverted.
B) virtual and inverted.
C) real and upright.
D) virtual and upright.
E) virtual and enlarged.

Question 52

A 6.0 cm tall object is placed 20 cm in front of a convex mirror with focal -100 cm focal length.Where is the image formed?

A) 80 cm behind the mirror
B) 25 cm behind the mirror
C) 17 cm behind the mirror
D) 17 cm in front of the mirror
E) 25 cm in front of the mirror

Question 53

A 25 cm focal length mirror has a 3.0 cm tall object placed 20 cm in front of it.Where is the image,and is it real or virtual?

A) 5.0 cm behind the mirror,virtual
B) 11 cm in front of the mirror,real
C) 100 cm in front of the mirror,real
D) 100 cm behind the mirror,virtual
E) 45 cm behind the mirror,virtual

Question 54

A 6.0 cm tall object is placed 20 cm in front of a convex mirror with focal -100 cm focal length.What is the size of the image formed?

A) 5.0 cm
B) 7.2 cm
C) 7.5 cm
D) 30 cm
E) 12 cm

Question 55

A concave mirror has a 12 cm tall object placed 40 cm in front of it.An image forms 60 cm in front of the mirror.What is the size and orientation of the image?

A) 8.0 cm,inverted
B) 8.0 cm,upright
C) 18 cm,inverted
D) 18 cm,upright
E) 24 cm,upright

Question 56

A thin lens of focal length 12.5 cm has a 5.0 cm tall object placed 10 cm in front of it.What is the size and orientation of the image?

A) 4.0 cm,inverted
B) 4.0 cm,upright
C) 8.9 cm,inverted
D) 8.9 cm,upright
E) 25 cm,upright

Question 57

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

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

Question 58

Which of these statements is true for the image formed by an object placed in front of a thin lens?

A) convex lenses never produce virtual images
B) real images are always enlarged
C) real images are always inverted
D) virtual images are always inverted

Question 59

A 9.0 cm object is placed in from 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 and the most inclusive?

A) the magnification is 1/3
B) the magnification is -1/3
C) the image is virtual
D) the magnification is 1/3 and the image is virtual
E) the magnification is -1/3 and the image is virtual

Question 60

A lens of focal length f is used to project an image of a solar eclipse on a flat sheet of paper.Which of the following image distances gives the clearest image in this case?

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

Question 61

An object placed at a distance closer to a converging lens than the focal point always produces an image that is

A) The same size as the object
B) Smaller than the object
C) Virtual
D) Inverted

Question 62

In a laboratory experiment,you are given two unknown substances and a laser.One of the substances is a liquid in which you place the laser.The other is a tank made of a transparent solid.You aim the laser downward at the tank bottom - and find that the reflected ray is fully polarized when the angle of incidence is 54 $^{\circ}$ .What is the transmitted angle for the ray transmitted into the tank bottom?

A) 39 $^{\circ}$
B) 47 $^{\circ}$
C) can't answer this without knowing the indices of refraction.
D) 36 $^{\circ}$

Question 63

It is found that a laser bounced off a glass surface incident at 57 degrees produces a transmitted beam angle of 38 degrees with respect to the vertical.At what incident angle will the reflected laser beam be fully polarized?

A) 46 $^{\circ}$
B) 36 $^{\circ}$
C) 54 $^{\circ}$
D) 43 $^{\circ}$

Question 64

It is found that at a laser bounced off the surface of a liquefied gas is perfectly polarized when the angle of incidence of the laser beam is 45.7 degrees from the vertical.What is the index of refraction of this material?

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

Question 65

The image formed by a diverging lens of a real object is always

A) Smaller than the object
B) Inverted
C) Larger than the object
D) Virtual
E) Real

Question 66

An object placed at a distance farther from a converging lens than the focal point always produces an image that is

A) The same size as the object
B) Inverted
C) Virtual
D) Smaller than the object

Question 67

A fish looks up at his attacker,an eagle,who is straight above the fish - though the fish lies 15cm beneath the surface of the water and the eagle is 1.5m above the surface.How far above the fish does the eagle appear to be?

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

Question 68

An innovative physics professor conducts laboratory exercises in the college swimming pool.Suppose that one exercise was the measurement of the degree of polarization by bouncing laser light off the vertically-oriented transparent polycarbonate side wall of the pool.The laser is shone on the pool wall at an angle of 42 degrees with respect to the vertical,and at that angle the reflected ray is perfectly polarized.What is the index of refraction of the material? It will help to recall that the index of refraction of water is 1.33.

A) 1.11
B) 1.28
C) 1.20
D) 1.48

Question 69

1.76m tall man looks at his reflection in a plane mirror.He stands 4.2m away from the window.How far from his eyes are the images of his feet? Assume his eyes are 5cm below the top of his head.

A) 8.4m
B) 11.1m
C) 4.2m
D) 4.53m

Question 70

The critical angle for total internal reflection is a:

A) is a single angle for which transmission through the boundary is zero
B) a maximum angle of incidence,below which no light is transmitted through the boundary
C) minimum angle of incidence,above which no light is transmitted through the boundary
D) may be either a minimum or a maximum angle,depending on which of the indices of refraction is larger

Question 71

An innovative physics professor conducts laboratory exercises in the college swimming pool.Suppose that one exercise was the measurement of the degree of polarization by bouncing laser light off a surface of a crystal.A laser bounced off the crystal surface is found to be perfectly polarized when the angle of incidence of the laser beam is 57 degrees from the vertical.What is the index of refraction of the crystal? It will help to recall that the index of refraction of water is 1.33.

A) 1.17
B) 1.12
C) 1.54
D) 2.05

Question 72

You are experimentally determining the critical angle for a novel transparent solid whose index of refraction is less than that of water (n=1.33) but greater than that of air (n=1.00).Your experimental method involves work underwater in which you observe whether there is any transmitted ray at the water/solid interface as you vary the angle of incidence on the solid surface.When your device reaches an incident angle of 53 degrees you find that the transmitted ray vanishes.What is the index of refraction for this new solid?

A) 1.16
B) 0.57
C) 1.06
D) 0.53

Question 73

It is found that a laser bounced off a glass surface is perfectly polarized when the angle of incidence of the laser beam is 57 degrees from the vertical.What is the angle of the transmitted beam in the case of this material?

A) 29 $^{\circ}$
B) 43 $^{\circ}$
C) 33 $^{\circ}$
D) 40 $^{\circ}$

Question 74

Brewster's angle for a given interface is _______________ the critical angle for total internal reflection for the same interface.

A) always greater than
B) either greater than or less than.
C) always less than
D) always equal to

Question 75

You are conducting an experiment with a converging lens and have set it up to produce a real image of a tree in the distance.You then cover the top half of the lens with opaque paper.What occurs?

A) The bottom half of the image is missing
B) Nothing happens
C) The image becomes half as large
D) The image is complete,but dimmer than it was
E) The top half of the image is missing

Question 76

An innovative physics professor conducts laboratory exercises in the college swimming pool.Suppose that one exercise was the measurement of the degree of polarization by bouncing laser light off a surface of glass.If the glass used has an index of refraction of 1.52,at what angle of incidence will the reflected beam be perfectly polarized? It will help to recall that the index of refraction of water is 1.33.

A) 61 $^{\circ}$
B) 49 $^{\circ}$
C) 41 $^{\circ}$
D) 39 $^{\circ}$

Question 77

A coin has been dropped inadvertently into a bucket full of cleaning fluid (n=1.13).The bottom of the bucket is 15cm beneath the top - how far beneath the surface does the washer therefore APPEAR to be?

A) 17.0cm
B) 13.3cm
C) More information is needed
D) 7.5cm

Question 78

Two plane mirrors are joined at a right angle.A beam of light is shone on one of the mirrors at an angle of incidence of 22 degrees,such that the reflected ray strikes the other mirror.What is the angle of incidence for the beam that strikes the second mirror?

A) 23 $^{\circ}$
B) 68 $^{\circ}$
C) 43 $^{\circ}$
D) 22 $^{\circ}$

Question 79

Fiber optic cable is in the form of a cylinder of fiber with index of refraction 1.67 and cladding around the outside of index of refraction 1.45.What is the maximum angle for light rays inside the fiber with respect to the cable's axis for which the light will be fully transmitted thanks to total internal reflection?

A) 30 $^{\circ}$
B) 60 $^{\circ}$
C) 41 $^{\circ}$
D) 49 $^{\circ}$

Question 80

When a light ray meets an interface between two media,the angle of refraction is _______ the angle of incidence.

A) Always less than
B) Always greater than
C) May be greater than,equal to,or less than
D) Equal to