Deck 23: Mirrors and Lenses

Question 1

You stand two feet away from a plane mirror.How far is it from you to your image?

A)2 ft
B)3 ft
C)4 ft
D)1 ft
E)​8 ft

Answer 1

4 ft

Question 2

Two plane mirrors make an angle of 50° with one another.A ray of light parallel to mirror #1 reflects off mirror #2 and then strikes mirror #1.What is the angle of incidence the ray makes with mirror #1?

A)50°
B)The answer is not given.
C)40°
D)55°

Answer 2

40°

Question 3

When the reflection of an object is seen in a plane mirror,the distance from the mirror to the image depends on

A)the wavelength of light used for viewing.
B)the distance from the object to the mirror.
C)the distance of both the observer and the object to the mirror.
D)the size of the object.

Answer 3

the distance from the object to the mirror.

Question 4

The lateral magnification for a flat mirror

A)is a function of the object distance.
B)is a function of the image distance.
C)is a function of the object and image distance.
D)is 1.

Question 5

If a virtual image is formed along the principal axis 12 cm from a concave mirror with the focal length 23 cm,what is the object distance from the mirror?

A)11.0 cm
B)25 cm
C)13 cm
D)7.9 cm
E)4.0 cm

Question 6

Which of the following best describes the image of a concave mirror when the object is at a distance greater than twice the focal point distance from the mirror?

A)virtual,upright and magnification greater than one
B)real,inverted and magnification less than one
C)virtual,upright and magnification less than one
D)real,inverted and magnification greater than one

Question 7

The magnification for a flat mirror:

A)is a function of the image distance.
B)is a function of the object distance.
C)is a function of the object and image distances.
D)is 1.

Question 8

The real image of an object is located 18.8 cm away from a concave mirror,which has a focal length of 8.20 cm.How far is the object from the mirror?

A)10.6 cm
B)16.4 cm
C)6.88 cm
D)14.5 cm
E)18.8 cm

Question 9

A corner cube is formed by three plane mirrors perpendicular to one another resulting in a retroreflector.What is the angle between the directions of an incoming ray of light and of the corresponding outgoing ray of light for this device?

A)90°
B)180°
C)0°
D)360°

Question 10

Which of the following best describes the image from a plane mirror?

A)virtual and magnification greater than one
B)real and magnification less than one
C)virtual and magnification equal to one
D)real and magnification equal to one

Question 11

If a man wishes to use a plane mirror on a wall to view both his head and his feet as he stands in front of the mirror,the required length of the mirror:

A)is equal to the height of the man.
B)is equal to one half the height of the man.
C)depends on the distance the man stands from the mirror.
D)depends on both the height of the man and the distance from the man to the mirror.

Question 12

A convex mirror with focal length of -16.2 cm forms an image 11.7 cm behind the surface.Where is the object located as measured from the surface?

A)22.2 cm
B)4.50 cm
C)6.79 cm
D)42.1 cm
E)11.7 cm

Question 13

A woman looking in a makeup mirror sees her face at twice its actual size and right-side up.If she is 21.0 cm from the mirror,what is its focal length?

A)14.0 cm
B)42.0 cm
C)10.5 cm
D)42.0 cm.
E)21.0 cm

Question 14

Which of the following best describes the image of a concave mirror when the object's distance from the mirror is less than the focal point distance?

A)virtual,upright and magnification greater than one
B)real,inverted and magnification less than one
C)virtual,upright and magnification less than one
D)real,inverted and magnification greater than one

Question 15

How large should a wall-mounted mirror be to view the upper half of one's height,h?

A)h
B)h/2
C)h/4
D)The answer is not given.

Question 16

Which of the following best describes the image of a convex mirror when the object's distance from the mirror is less than the absolute value of the focal point distance?

A)virtual,upright and magnification greater than one
B)real,inverted and magnification less than one
C)virtual,upright and magnification less than one
D)real,inverted and magnification greater than one

Question 17

A concave mirror forms a real image at 35.2 cm from the mirror surface along the principal axis.If the corresponding object is at a 12.6-cm distance,what is the mirror's focal length?

A)22.6 cm
B)47.8 cm
C)10.8 cm
D)9.28 cm
E)19.6 cm

Question 18

When the reflection of an object is seen in a plane mirror,the image is

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

Question 19

Which best describes the image of a concave mirror when the object is located somewhere between the focal point and twice the focal point distance from the mirror?

A)virtual,upright and magnification greater than one
B)real,inverted and magnification less than one
C)virtual,upright and magnification less than one
D)real,inverted and magnification greater than one

Question 20

If a virtual image is formed 14.5 cm along the principal axis from a convex mirror of focal length -19.5 cm,how far is the object from the mirror?

A)56.6 cm
B)14.5 cm
C)5.00 cm
D)20.0 cm
E)6.80 cm

Question 21

A girl is standing in front of a concave mirror.Consider two rays of light,one from her nose and one from her mouth that are parallel as they are traveling toward the mirror.These rays will come together

A)at the focal point.
B)at the center of curvature.
C)at the image point.
D)behind the mirror if she is too close to the mirror.

Question 22

A container is filled with fluid 1 and the apparent depth of the fluid is 5 cm.The container is next filled with fluid 2,and the apparent depth of this fluid is 2 cm.What is the ratio of the indices of refraction of these fluids?

A)n₁/n₂ = 2/5
B)n₁/n₂ = 5/2
C)n₁/n₂ =
D)n₁/n₂ =
E)More information is needed to find the ratio.

Question 23

If an optical system consists only of an object and a single convex mirror,

A)the image will sometimes be inverted.
B)the magnification will sometimes have an absolute value greater than 1.
C)the image distance will never be negative.
D)the image will always be virtual.

Question 24

A glass block,for which n = 1.52,has a blemish located 3.3 cm from one surface.At what distance from that surface does the image of the blemish appear to the outside observer?

A)5.0 cm
B)2.2 cm
C)4.1 cm
D)2.7 cm
E)​3.3 cm

Question 25

A goldfish is swimming in water (n = 1.33)inside a spherical plastic bowl of index of refraction 1.33.If the goldfish is 10.4 cm from the front wall of the 26.4-cm radius bowl,where does the goldfish appear to an observer in front of the bowl?

A)7.12 cm behind the plastic
B)15.9 cm behind the plastic
C)12.2 cm behind the plastic
D)8.67 cm behind the plastic
E)12.2 cm behind the plastic.

Question 26

Which of the following statements is true?​

A)​For an object at a concave mirror's center of curvature,the image is real and upright.
B)​For an object in front of a convex mirror,the image is always virtual and upright.
C)​As an object approaches the focal point of a concave mirror,the image size shrinks to zero.
D)​All of the above statements are true.

Question 27

A convex mirror with a focal length of -28.0 cm forms an image 11.3 cm behind the surface.If the object height is 2.00 cm what is the image height?

A)1.19 cm
B)3.35 cm
C)1.35 cm
D)2.00 cm
E)0.807 cm

Question 28

A solid glass sphere with a radius of 4.50 cm and index of refraction of 1.63 has a small coin embedded 2.50 cm from the front surface of the sphere.For the viewer looking at the coin through the glass,at what distance from the front surface of the glass does the coin's image appear to be located?

A)1.95 cm
B)2.50 cm
C)3.85 cm
D)3.45 cm
E)​1.53 cm

Question 29

A candle is 32.0 cm in front of a convex spherical mirror of radius of curvature 68.0 cm.What are the image distance and the magnification,respectively?

A)-16.5 cm,+ 0.515
B)-21.8 cm,- 1.94
C)-36.0 cm,+ 0.242
D)-1.9 cm,+ 1.94
E)16.5 cm,- 0.515

Question 30

Parallel rays of light that hit a concave mirror will come together

A)at the center of curvature.
B)at the focal point.
C)at a point half way to the focal point.
D)at infinity.

Question 31

An object of length 3.00 cm is inside a plastic block with index of refraction 1.40.If the object is viewed through the top surface of the block at a non-zero angle from the normal,where is the object relative to its image?

A)in the same direction as its image
B)above the direction of its image
C)below the direction of its image
D)More information is needed.

Question 32

An object placed 19.0 cm from a concave mirror produces a real image 12.7 cm from the mirror.If the object is now moved to a new position 27.0 cm from the mirror,where is the new image located as measured from the mirror?

A)7.61 cm
B)10.6 cm
C)5.94 cm
D)18.0 cm
E)20.7 cm

Question 33

A container is filled with fluid 1,and the apparent depth of the fluid is 9.00 cm.The container is next filled with fluid 2,and the apparent depth of this fluid is 6.86 cm.If the index of refraction of the first fluid is 1.37,what is the index of refraction of the second fluid?

A)1.80
B)2.41
C)1.57
D)1.20
E)More information is needed to find the value.

Question 34

An object is 20.0 cm from the surface of a spherical Christmas tree ornament that is 8.00 cm in diameter.What is the magnification of the image?

A)- 0.091
B)- 0.545
C)+ 0.091
D)+ 0.545
E)​+ 0.364

Question 35

An object is placed 10 cm in front of a mirror,and an image is formed that has a magnification of 2.Which of the following statements is false?

A)The focal length of the mirror is 20 cm.
B)The image is virtual.
C)There is enough information to select the correct answer.
D)This is the only true statement.

Question 36

An object is held at a distance of 19.0 cm from a convex mirror creating an image that is 1/6 the object size.What is the focal length of the mirror?

A)-3.8 cm
B)16 cm
C)-2.7 cm
D)-8.8 cm
E)23 cm

Question 37

When the reflection of an object is seen in a convex mirror the image will

A)always be real.
B)always be virtual.
C)may be either real or virtual.
D)will always be enlarged.

Question 38

When the reflection of an object is seen in a concave mirror the image will

A)always be real.
B)always be virtual.
C)may be either real or virtual.
D)will always be enlarged.

Question 39

Ron fills a beaker with glycerin (n = 1.473)to a depth of 4.0 cm.If he looks straight down through the glycerin surface,he will perceive the liquid to be what apparent depth?

A)5.9 cm
B)4.0 cm
C)2.7 cm
D)3.3 cm
E)4.9 cm

Question 40

An object of length 5.00 cm is inside a plastic block with index of refraction 1.50.If the object is viewed from directly above,what is the length of its image?

A)5.00 cm
B)7.50 cm
C)3.33 cm
D)4.08 cm
E)​2.22 cm

Question 41

When the midpoint of the face of the Sun appears to be on the horizon,where is the actual midpoint from the point of view of the observer?

A)above the horizon at sunrise and below the horizon at sunset
B)on the horizon
C)below the horizon
D)above the horizon

Question 42

Ansel places an object 34.8 cm from a thin convex lens along the axis.If a real image forms at a distance of 13.2 cm from the lens,what is the focal length of the lens?

A)34.8 cm
B)21.3 cm
C)13.2 cm
D)9.57 cm
E)21.6 cm

Question 43

For a converging lens with two curved surfaces,the radius of curvature for both surfaces is 13.1 cm.If the focal length is 16.5 cm,what must the index of refraction be?

A)1.40
B)1.79
C)1.52
D)1.56
E)1.63

Question 44

An object is placed at a distance of 41.4 cm from a thin lens along the axis.If a real image forms at a distance of 36.1 cm from the lens,on the opposite side from the object,what is the focal length of the lens?

A)19.3 cm
B)38.8 cm
C)10.6 cm
D)282 cm
E)6.21 cm

Question 45

A 1.40-cm-tall object is placed along the principal axis of a thin convex lens of 13.0 cm focal length.If the object distance is 19.2 cm,which of the following best describes the image distance and height,respectively?

A)7.75 cm and 4.34 cm
B)40.3 cm and 2.94 cm
C)7.75 cm and 7.27 cm
D)9.16 cm and 4.34 cm
E)41.4 cm and 0.668 cm

Question 46

A projector lens is needed to form an image on a screen 6 times the size of its corresponding object.The screen is located 8.65 m from the lens.What is the required focal length of the lens?

A)1.44 m
B)7.41 m
C)1.24 m
D)0.721 m
E)1.73 m

Question 47

Atmospheric refraction of light rays is responsible for

A)spherical aberration.
B)mirages.
C)chromatic aberration.
D)light scattering.

Question 48

Sally places an object 12.6 cm from a thin convex lens along its axis.The lens has a focal length of 14.8 cm.What are the respective values of the image distance and magnification?

A)-84.8 cm and + 6.73
B)84.8 cm and + 6.73
C)6.81 cm and + 5.73
D)-84.8 cm and -6.73
E)84.8 cm and -6.73

Question 49

What is the image distance of an object 1.85 m in front of a converging lens of focal length 26.3 cm?

A)+ 23.0 cm
B)-1.99 cm
C)+ 30.6 cm
D)+ 159 cm
E)+ 4.80 cm

Question 50

Which of the following best describes the image for a thin concave lens that forms whenever the magnitude of the object distance is less than that of the lens' focal length?

A)inverted,enlarged and real
B)upright,enlarged and virtual
C)upright,diminished and virtual
D)inverted,diminished and real

Question 51

Ellen places an object 48.4 cm from a concave lens.If a virtual image appears 24.6 cm from the lens on the same side as the object,what is the focal length of the lens?

A)-16.3 cm
B)-50.0 cm
C)732 cm
D)-23.8 cm
E)-36.5 cm

Question 52

An object is placed at a distance of 20.4 cm from a thin convex lens along its axis.The lens has a focal length of 13.0 cm.What are the values,respectively,of the image distance and magnification?

A)7.94 cm and 0.569
B)35.8 cm and - 0.363
C)7.40 cm and -1.76
D)35.8 cm and -1.76
E)7.40 cm and - 0.363

Question 53

When an image is inverted compared to the object,it is also

A)virtual.
B)reversed left to right.
C)enlarged.
D)diminished.

Question 54

A converging lens with two convex surfaces has a front surface with radius of curvature of 13.1 cm;the back surface has radius of curvature of 16.5 cm,and it is made from material with an index of refraction of 2.10.What is the focal length of the lens?

A)6.64 cm
B)57.8 cm
C)−57.8 cm
D)3.48 cm
E)30.3 cm

Question 55

An object,located 80.0 cm from a concave lens,forms an image 39.6 cm from the lens on the same side as the object.What is the focal length of the lens?

A)-26.5 cm
B)-120 cm
C)-78.4 cm
D)-80.8 cm
E)-20.0 cm

Question 56

If atmospheric refraction did not occur,how would the apparent time of sunrise and sunset be changed?

A)Both would be later.
B)Both would be earlier.
C)Sunrise would be later and sunset earlier.
D)Sunrise would be earlier and sunset later.

Question 57

Two thin lenses with 6.80-cm focal lengths at are mounted at opposite ends of a 18.8-cm long tube.An object is located 20.4 cm from one end of the tube.How far from the opposite end is the final image?

A)8.88 cm
B)32.5 cm
C)4.54 cm
D)8.60 cm
E)20.4 cm

Question 58

An object and a screen are separated by 15.0 cm.A convex lens is placed between them,6.82 cm from the object.In this position it causes a sharp image of the object to form on the screen.What is the focal length of the lens?

A)4.69 cm
B)41.0 cm
C)3.72 cm
D)12.5 cm
E)4.09 cm

Question 59

Which of the following best describes the image for a thin convex lens that forms whenever the object is at a distance less than one focal length from the lens?

A)inverted,enlarged and real
B)upright,enlarged and virtual
C)upright,diminished and virtual
D)inverted,diminished and real

Question 60

For a diverging lens with one flat surface,the radius of curvature for the curved surface is 25.0 cm.What must the index of refraction be so that the focal length is -17.0 cm?

A)0.680
B)1.68
C)2.47
D)1.74
E)1.47

Question 61

Reducing the lens aperture size is a scheme one can use to reduce the occurrence of which of the following effects?

A)spherical aberration
B)mirages
C)chromatic aberration
D)light scattering

Question 62

An image is formed using a convex lens,the image being 15 cm past the lens.A second lens is placed 25 cm past the first lens and another image is formed,this time 10 cm past the second lens.Which of the following statements is always true?

A)Both of the lenses have positive focal lengths.
B)The first lens is diverging,and the second is converging.
C)The first lens is converging,and the second is diverging.
D)None of the above statements is true.

Question 63

In an ideal case rays coming from an object toward a lens or mirror should be reasonably close to the optic axis.To the extent that this condition is not completely met,which one of the following effects occurs?

A)spherical aberration
B)mirages
C)chromatic aberration
D)light scattering

Question 64

Which of the following effects is the result of the fact that the index of refraction of glass will vary with wavelength?

A)spherical aberration
B)mirages
C)chromatic aberration
D)light scattering

Question 65

An object is placed 27.0 cm to the left of a lens of focal length 17.0 cm.39.0 cm to the right of this lens is a plane mirror.Where does the final image form?

A)6.9 cm to the right of the mirror
B)6.9 cm to the left of the mirror
C)32.1 cm to the left of the lens
D)45.9 cm to the left of the lens
E)28.6 cm to the left of the mirror

Question 66

When light goes through two or more separated lenses,

A)the image distance of the first lens (the one nearest the object)will be positive.
B)the final image can be inverted.
C)the image distance of the first lens will be the object distance for the second lens.
D)the object distance for the second lens will be negative.

Question 67

A convex lens has a focal length of magnitude F.At which of the following distances from this lens would a real object give an inverted virtual image?

A)1/2 F
B)2F
C)Any value greater than 2F.
D)This cannot be done with a convex lens.

Question 68

A contact lens is made of plastic with an index of refraction 1.50.The lens has an outer radius of curvature of + 1.65 cm and an inner radius of curvature of + 5.85 cm.What is its focal length?

A)-4.60 cm
B)+1.53 cm
C)+2.57 cm
D)+4.60 cm
E)-2.57 cm ​

Question 69

A concave mirror with focal length 16.0 cm is placed 45.0 cm to the left of the object.A convex lens of focal length 15.0 cm is placed 6.0 cm to the right of the object.Where is the image formed by both the mirror and the lens?

A)9.5 cm to the right of the object
B)35.1 cm to the right of the lens
C)15.5 cm to the right of the object
D)37.9 cm to the right of the lens
E)16.0 cm to the right of the lens

Question 70

An eyeglass lens is cut with one surface having a radius R₁ and the other surface having a radius R₂,with R₁ < R₂.Both positive radii are measured from the same side with R₁ being the side closer to the eye.Is this convex-concave lens a converging lens or a diverging lens?

A)This is a converging lens.
B)This is a diverging lens.
C)This can be either a converging or diverging lens,as more information is needed for a final determination.
D)This is neither,since a lens cannot be made this way.

Question 71

A fused combination of a diverging and converging lens pair each made from a different index of refraction glass,is used to reduce the occurrence of which of the following effects?

A)spherical aberration
B)mirages
C)chromatic aberration
D)light scattering

Question 72

A real object is place to the left of a converging lens and an image forms.Then,to the right of the converging lens a diverging lens is placed.A real,inverted final image forms to the right of the diverging lens.Which of the following could give this result?

A)An upright virtual image caused by the first lens forms between the two lenses.
B)An inverted real image caused by the first lens forms between the two lenses.
C)A real,upright image was formed by the first lens to the right of where the diverging lens is to be placed.
D)A real,inverted image was formed by the first lens to the right of where the diverging lens is to be placed.

Question 73

Use of a parabolic mirror,instead of one made of a circular arc surface,can be used to reduce the occurrence of which of the following effects?

A)spherical aberration
B)mirages
C)chromatic aberration
D)light scattering

Question 74

A thin lens has a focal length of 10.00 cm for red light.If the index of refraction for the lens material tends to decrease with increasing wavelength,what is the focal length of the lens for blue light?

A)also 10.00 cm
B)less that 10.00 cm
C)more than 10.00 cm
D)It depends on whether the lens is converging or diverging.

Question 75

A lens has a focal length of 56.2 cm in air.If this lens were immersed in water,what focal length would result? The index of refraction of the lens is 1.96 and that of water is 1.333.The focal length of a thin lens with index n₁ submerged in a liquid with index n₂ is given by the modified lens-maker's formula:
)

A)115 cm
B)27.5 cm
C)169 cm
D)82.6 cm
E)61.0 cm

Question 76

A concave mirror has radius R.When an object is located a distance 2R from the lens,which describes the image formed?

A)real,inverted,diminished
B)real,inverted,enlarged
C)virtual,upright,diminished
D)real,inverted,of equal size

Question 77

A lens of 15.0-cm focal length is placed 21.0 cm to the right of the object and a mirror of focal length -22.0 cm is placed 59.0 cm to the right of the lens.Where is the image formed by the mirror?

A)3.9 cm to the right of the mirror
B)15.5 cm to the left of the mirror
C)9.2 cm to the left of the lens
D)5.0 cm to the right of the mirror
E)​5.0 cm to the left of the mirror

Question 78

A real object is place a distance d from a converging lens.The object is then moved to a distance 2d from the converging lens.Which of the following statements is false?

A)The image in the first case with the object at distance d can be the larger one.
B)The image in the second case with the object at distance 2d can be the larger one.
C)If both images are real,the image in the second case is smaller.
D)If the image in the first case is real,the image in the second case is upright.