Deck 32: Light: Reflection and Refraction

Question 1

The explanation of the behavior of light based on the ray model is called "geometric optics."

Answer 1

True

Question 2

Which of the following sets of characteristics describes the image formed by a plane mirror?

A)real and inverted
B)real and upright
C)virtual and upright
D)virtual and inverted
E)All of the previous statements can be correct.

Answer 2

virtual and upright

Question 3

A concave mirror is also known as a diverging mirror.

Answer 3

False

Question 4

An object at the center of curvature of a concave mirror forms an inverted image at the center of curvature itself.

Question 5

A convex mirror always produces a virtual image smaller than the object.

Question 6

An image formed when the light rays pass through the image location, and could appear on paper or film placed at that location is referred to as a(n)

A)real image.
B)virtual image.
C)imaginary image.
D)positive image.
E)negative image.

Question 7

Reflection, refraction, and the formation of images by mirrors and lenses has been successful described by the

A)wave model of light.
B)ray model of light.
C)particle model of light.
D)electro model of light.
E)none of the given answers

Question 8

For total internal reflection to take place, light must go from a medium of lower index of refraction to a medium of higher index of refraction.

Question 9

An image formed when the light rays do not actually pass through the image location, and would not appear on paper or film placed at that location is referred to as a(n)

A)real image.
B)virtual image.
C)imaginary image.
D)positive image.
E)negative image.

Question 10

State how to draw the three rays for finding the image position due to a curved mirror.

Question 11

Plane mirrors produce images which

A)are always smaller than the actual object.
B)are always larger than the actual object.
C)are always the same size as the actual object.
D)could be smaller or the same size as the actual object, depending on the placement of the object.
E)could be larger or the same size as the actual object, depending on the placement of the object.

Question 12

A concave mirror always produces a real image of an object placed in front of it.

Question 13

Magnification is positive for inverted images.

Question 14

The reflection of light from a rough surface is called specular reflection.

Question 15

In a concave mirror the inside of the spherical surface is the reflecting surface.

Question 16

After striking a concave mirror, a paraxial beam of light passes through the mirror's focal point.

Question 17

The image distance, d_i, is positive for images in front of a mirror.

Question 18

The image formed in a plane mirror is

A)at the same distance in front of the mirror as the object is in front of the mirror.
B)at a shorter distance in front of the mirror than the distance that the object is in front of the mirror.
C)at the same distance behind the mirror as the object is in front of the mirror.
D)at a shorter distance behind the mirror than the distance the object is in front of the mirror.
E)at a larger distance behind the mirror than the distance the object is in front of the mirror.

Question 19

When a beam of light in air is incident at an angle of incidence θ_i < 90° on a piece of glass, the angle of refraction is larger than the angle of incidence.

Question 20

The angle of incidence

A)must equal the angle of reflection.
B)is always less than the angle of reflection.
C)is always greater than the angle of reflection.
D)may be less than or equal to the angle of reflection.
E)may be greater than or equal to the angle of reflection.

Question 21

An object is placed at a concave mirror's center of curvature. The image produced by the mirror is located

A)out beyond the center of curvature.
B)at the center of curvature.
C)between the center of curvature and the focal point.
D)at the focal point.
E)between the focal point and the surface of the mirror.

Question 22

If you stand in front of a convex mirror, at the same distance from it as its focal length,

A)you won't see your image because there is none.
B)you won't see your image because it's focused at a different distance.
C)you will see your image and you will appear smaller.
D)you will see your image and you will appear larger.
E)you will see your image at your same height.

Question 23

If the absolute value of the magnification is larger than one, then the image is

A)larger than the object.
B)the same size as the object.
C)smaller than the object.

Question 24

If the absolute value of the magnification is smaller than one, then the image is

A)larger than the object.
B)the same size as the object.
C)smaller than the object.

Question 25

The image formed by a concave mirror when the object is placed between the mirror and the focal point has the following characteristics:

A)virtual, upright, enlarged, image distance is larger than object distance
B)virtual, upright, reduced, image distance is smaller than object distance
C)real, inverted, enlarged, image distance is larger than object distance
D)real, upright, enlarged, image distance is larger than object distance
E)virtual, inverted, reduced, image distance is smaller than object distance

Question 26

If the absolute value of the magnification is equal to one, then the image is

A)larger than the object.
B)the same size as the object.
C)smaller than the object.

Question 27

A light ray, traveling obliquely to a concave mirror's axis, crosses the axis at the mirror's center of curvature before striking the mirror's surface. After reflection, this ray

A)travels parallel to the mirror's axis.
B)travels at right angles to the mirror's axis.
C)passes through the mirror's center of curvature.
D)passes through the mirror's focal point.
E)passes through the axis midway between the mirror's focal point and center of curvature.

Question 28

How tall must a plane mirror be in order for you to be able to see your full image in it?

A)the same height as you
B)1/4 of your height
C)half of your height
D)3/4 of your height
E)twice your height

Question 29

A light ray is reflected by two mirrors that are perpendicular. The new direction of the ray is

A)180° from the original direction.
B)135° from the original direction.
C)45° from the original direction.
D)between 90° and 180° from the original direction.
E)90° from the original direction.

Question 30

A concave mirror has

A)no focal length.
B)a positive or negative focal length depending on the object position.
C)a positive focal length.
D)a negative focal length.
E)a positive or negative focal length depending on the object size.

Question 31

If the image distance is negative, the image formed by a mirror is a(n)

A)real image.
B)virtual image.
C)imaginary image.
D)positive image.
E)negative image.

Question 32

A beam of light that is parallel to the principal axis is incident on a convex mirror. What happens to the reflected beam of light?

A)It also is parallel to the principal axis.
B)It is perpendicular to the principal axis.
C)It appears to be coming from the focal point on the other side of the mirror.
D)It appears to be coming from the center of curvature of the mirror.
E)It appears to be coming from a point between the focal point and the center of curvature of the mirror.

Question 33

If you stand in front of a convex mirror, at the same distance from it as its radius of curvature,

A)you won't see your image because there is none.
B)you won't see your image because it's focused at a different distance.
C)you will see your image and you will appear smaller.
D)you will see your image and you will appear larger.
E)you will see your image at your same height.

Question 34

A beam of light that is parallel to the principal axis is incident on a concave mirror. What happens to the reflected beam of light?

A)It also is parallel to the principal axis.
B)It is perpendicular to the principal axis.
C)It passes through the center of curvature of the mirror.
D)It passes through the focal point of the mirror.
E)It passes between the focal point and the center of curvature of the mirror.

Question 35

A light ray, traveling obliquely to a concave mirror's surface, crosses the axis at the mirror's focal point before striking the mirror's surface. After reflection, this ray

A)travels parallel to the mirror's axis.
B)travels at right angles to the mirror's axis.
C)passes through the mirror's center of curvature.
D)passes through the mirror's focal point.
E)passes through the axis midway between the mirror's focal point and center of curvature.

Question 36

If the image distance is positive, the image formed by a mirror is a(n)

A)real image.
B)virtual image.
C)imaginary image.
D)positive image.
E)negative image.

Question 37

Is it possible to see a virtual image?

A)No, since the rays that seem to emanate from a virtual image do not in fact emanate from the image.
B)No, since virtual images do not really exist.
C)Yes, the rays that appear to emanate from a virtual image can be focused on the retina just like those from an illuminated object.
D)Yes, since almost everything we see is virtual because most things do not themselves give off light, but only reflect light coming from some other source.
E)Yes, but only indirectly in the sense that if the virtual image is formed on a sheet of photographic film, one could later look at the picture formed.

Question 38

If you stand in front of a concave mirror, exactly at its focal point,

A)you won't see your image because there is none.
B)you won't see your image because it's focused at a different distance.
C)you will see your image, and you will appear smaller.
D)you will see your image and you will appear larger.
E)you will see your image at your same height.

Question 39

To find an image by ray tracing requires

A)four rays.
B)two rays.
C)eight rays.
D)three rays.
E)only one ray.

Question 40

A convex mirror has

A)no focal length.
B)a positive or negative focal length depending on the object position.
C)a positive focal length.
D)a negative focal length.
E)a positive or negative focal length depending on the object size.

Question 41

At a quiet pond with crystal clear water, you decide to fish with bow and arrow. When you aim at the fish you see, you must aim

A)closer to the surface then you perceive the fish to be.
B)directly at the fish.
C)deeper then you perceive the fish to be.
D)It depends on how large the fish is.
E)It depends on how deep the pond is.

Question 42

For all transparent material substances, the index of refraction

A)is less than 1.
B)is greater than 1.
C)is equal to 1.
D)is less than or equal to 1.
E)is greater than or equal to 1.

Question 43

An index of refraction less than one for a medium would imply

A)that the speed of light in the medium is the same as the speed of light in vacuum.
B)that the speed of light in the medium is greater than the speed of light in vacuum.
C)that the speed of light in the medium is less than the speed of light in vacuum.
D)refraction is not possible.
E)reflection is not possible.

Question 44

A ray of light, which is traveling in air, is incident on a glass plate at a 45° angle. The angle of refraction in the glass

A)is less than 45°.
B)is greater than 45°.
C)is equal to 45°.
D)could be any of the above; it all depends on the index of refraction of glass.

Question 45

When light passes through a prism the color refracted most is

A)green.
B)red.
C)violet.
D)blue.
E)yellow.

Question 46

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

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

Question 47

Light traveling at an angle into a denser medium is refracted

A)toward the normal.
B)away from the normal.
C)perpendicular to the normal.
D)parallel to the normal.
E)equally.

Question 48

The index of refraction of diamond is 2.42. This means that a given frequency of light travels

A)2.42 times faster in air than it does in diamond.
B)2.42 times faster in diamond than it does in air.
C)2.42 times faster in vacuum than it does in diamond.
D)2.42 times faster in diamond than it does in vacuum.
E)2.42 times faster in vacuum than it does in air.

Question 49

The spreading of white light into its spectrum is called

A)refraction.
B)dispersion.
C)reflection.
D)demodulation.
E)rainbowing.

Question 50

When light enters a material of higher index of refraction, its speed

A)decreases.
B)first increases then decreases.
C)stays the same.
D)increases.
E)first decreases then increases.

Question 51

A beam of light in air is incident on a glass slab at an angle of incidence θ_i < 90°. After entering the glass slab, the beam of light

A)does not change its path.
B)follows the normal to the glass slab.
C)bends away from the normal drawn at the point of contact.
D)bends closer to the normal drawn at the point of contact.

Question 52

If the magnification of a mirror is negative, which of the following is correct?

A)The image is upright and the mirror is convex.
B)The image is inverted and the mirror is convex.
C)The image is inverted and the mirror is concave.
D)All of the previous answers can be correct.
E)None of the previous answers is correct.

Question 53

Which color of light undergoes the smallest refraction when passing from air to glass?

A)red
B)yellow
C)green
D)violet
E)blue.

Question 54

A single concave spherical mirror produces an image which is

A)always virtual.
B)always imaginary.
C)always real.
D)real only if the object distance is less than f.
E)real only if the object distance is greater than f.

Question 55

The angle of incidence

A)must equal the angle of refraction.
B)is always less than the angle of refraction.
C)is always greater than the angle of refraction.
D)may be greater than, less than, or equal to the angle of refraction.

Question 56

An object is placed in front of a convex mirror at a distance closer than the focal length of the mirror. The image will appear

A)behind the mirror.
B)upright and reduced.
C)upright and enlarged.
D)inverted and reduced.
E)inverted and enlarged.

Question 57

Convex spherical mirrors produce images which

A)are always smaller than the actual object.
B)are always larger than the actual object.
C)are always the same size as the actual object.
D)could be larger than or the same size as the actual object, depending on the placement of the object.
E)could be smaller than or the same size as the actual object, depending on the placement of the object.

Question 58

A single convex spherical mirror produces an image which is

A)always virtual.
B)always imaginary.
C)always real.
D)real only if the object distance is less than f.
E)real only if the object distance is greater than f.

Question 59

Concave spherical mirrors produce images which

A)are always smaller than the actual object.
B)are always larger than the actual object.
C)are always the same size as the actual object.
D)could be smaller than, larger than, or the same size as the actual object, depending on the placement of the object.

Question 60

An object is placed in front of a convex mirror at a distance larger than twice the focal length of the mirror. The image will appear

A)in front of the mirror.
B)inverted and reduced.
C)inverted and enlarged.
D)upright and reduced.
E)upright and enlarged.

Question 61

A mirror is rotated at an angle of 10° from its original position. How much is the rotation of the angle of reflection?

A)10°
B)5°
C)15°
D)20°
E)40°

Question 62

You run directly towards a plane mirror at 5 m/s. How fast do you approach your image?

A)0 m/s
B)5 m/s
C)7 m/s
D)10 m/s
E)2 m/s

Question 63

An object is placed 12 cm in front of a curved mirror. The magnification of the image is -3.0. What is the focal length of the mirror?

A)12 cm
B)9.0 cm
C)24 cm
D)36 cm
E)16 cm

Question 64

Light strikes a 5.0 cm thick sheet of glass with index of refraction 1.50 at an angle of incidence in air of 50°. (a) What is the angle of refraction in the glass?
(b) After traveling through the glass the light re-emerges into the air. What is the final angle of refraction in air?
(c) Determine the amount its path is displaced when it leaves the glass from what it had been before entering the glass.

Question 65

A laser beam strikes a plane's reflecting surface with an angle of incidence of 43°. What is the angle between the incident ray and the reflected ray?

A)43°
B)86°
C)45°
D)90°
E)0°

Question 66

The critical angle for a beam of light passing from water into air is 48.8°. This means that all light rays with an angle of incidence greater than this angle will be

A)absorbed.
B)totally reflected.
C)partially reflected and partially transmitted.
D)totally transmitted.
E)totally polarized.

Question 67

An object is located 3.8 m in front of a plane mirror. The image formed by the mirror appears to be

A)1.9 m in front of the mirror.
B)on the mirror's surface.
C)1.9 m behind the mirror's surface.
D)3.8 m in front of the mirror.
E)3.8 m behind the mirror's surface.

Question 68

John's face is 20 cm in front of a concave shaving mirror. If he observes his image to be twice as big and erect, what is the focal length of the mirror?

A)10 cm
B)20 cm
C)30 cm
D)40 cm
E)50 cm

Question 69

A lighted candle is 10 m away from a wall. A concave mirror is being used to project an image of the candle onto the wall. If the image is going to be 3.0 times the size of the object, how far should the mirror be from the wall?

A)6.5 m
B)7.0 m
C)6.0 m
D)5.5 m
E)15 m

Question 70

If a length of lucite that is being used as a light pipe gets wet, the critical angle

A)decreases.
B)is unaffected.
C)doubles.
D)is meaningless since lucite cannot be used as a light pipe.
E)increases.

Question 71

A beam of white light is incident on a thick glass plate with parallel sides, at an angle between 0° and 90° with the normal. Which color emerges from the other side first?

A)red
B)green
C)blue.
D)violet
E)None of the given; all colors emerge at the same time.

Question 72

If n₁ is the index of refraction for the incident medium and n₂ is the index for the refracting medium, the critical angle will exist

A)in all cases, it will just have different values.
B)when n₁ < n₂.
C)when n1 = n2.
D)never.
E)when n₁ > n₂.

Question 73

The side mirror on a car is convex and has a radius of curvature of 25 cm. Another car is following, 20 m behind the mirror. If the height of the car is 1.6 m, how tall is the image?

A)5 cm
B)2 cm
C)4 cm
D)3 cm
E)1 cm

Question 74

A concave mirror with a radius of 20 cm creates a real image 30 cm from the mirror. What is the object distance?

A)50 cm
B)20 cm
C)15 cm
D)7.5 cm
E)5.0 cm

Question 75

The condition for total internal reflection can be predicted from Snell's law since

A)the index of refraction of glass is about 1.5.
B)the index of refraction of plastic is about 1.5.
C)the value of tangent can be 1.0.
D)the maximum value of the sine is 1.0.
E)the maximum value of the sine is 1.5.

Question 76

A spherical mirror has a radius of curvature of 22 cm. If the mirror is concave, its focal length is

A)-11 cm.
B)-22 cm.
C)11 cm.
D)-44 cm.
E)22 cm.

Question 77

How far are you from your image when you stand 0.75 m in front of a vertical plane mirror?

A)0.38 m
B)0.75 m
C)1.5 m
D)3.0 m
E)none of the given answers

Question 78

A object is 12 cm in front of a concave mirror, and the image is 3.0 cm in front of the mirror. What is the focal length of the mirror?

A)0.25 cm
B)15 cm
C)4.0 cm
D)2.4 cm
E)1.3 cm

Question 79

A person walks toward a plane mirror at 2.0 ft/s. She is approaching her image in the mirror at a speed of

A)1.0 ft/s.
B)3.0 ft/s.
C)2.0 ft/s.
D)4.0 ft/s.
E)5.0 ft/s.

Question 80

A spherical mirror has a radius of curvature of 22 cm. If the mirror is convex, its focal length is

A)-11 cm.
B)-44 cm.
C)22 cm.
D)11 cm.
E)-22 cm.