Deck 32: Optical Images

Question 1

A convenience's store clerk observes at shopper 4 m in front of a convex mirror.The image of the shopper is located 1.5 m behind the mirror.The focal length of the mirror is

A)-2.5 m
B)-2.4 m
C)-0.67 m
D)-1.1 m
E)none of the above

Answer 1

-2.4 m

Question 2

An object is placed 10 inches in front of a concave mirror that has a radius of curvature of 8 inches.The image is located

A)4.75 inches in front of the mirror.
B)4.75 inches behind the mirror.
C)3 inches behind the mirror.
D)6.67 inches behind the mirror.
E)6.67 inches in front of the mirror.

Answer 2

6.67 inches in front of the mirror.

Question 3

A concave spherical mirror can produce which one of the following types of images?

A)virtual,inverted,and magnified
B)real,erect,and magnified
C)diminished,erect,and virtual
D)magnified,erect,and virtual
E)diminished,real,and erect

Answer 3

magnified,erect,and virtual

Question 4

Dentists often use concave mirrors to see better.In order for the mirror to produce an enlarged image of a tooth,the tooth must be placed

A)at the focal point of the mirror.
B)further than the focal point of the mirror.
C)closer than the focal point of the mirror.
D)at any distance.
E)Concave mirrors cannot produce an enlarged image.

Question 5

How far must a man's face be located in front of a concave spherical shaving mirror of radius 120 cm for him to see an erect image of his face four times its real size?

A)-75 cm
B)45 cm
C)75 cm
D)90 cm
E)150 cm

Question 6

What is the minimum height of a plane mirror in which a standing woman can see her entire body reflected?

A)It must equal her height.
B)It depends on how far from the mirror the woman stands.
C)It depends on the focal length of the mirror.
D)It must be one-half her height.
E)It depends on the image distance.

Question 7

When you look at the image reflected from two plane mirrors placed at 90 ^$\circ$ ,the image

A)is real.
B)is inverted.
C)does not change handiness.
D)is compressed in the vertical direction.
E)None of the above statements is true.

Question 8

When an object is farther from a convex mirror than the mirror's focal point,the

A)magnification is less than one.
B)image distance is greater than the object distance.
C)magnification is equal to one.
D)image is real.
E)image is inverted.

Question 9

An object is 10 cm from a concave spherical mirror whose radius is 10 cm.The image is

A)real,inverted,and magnified.
B)real,inverted,and diminished.
C)real,inverted,and the same size.
D)virtual,erect,and magnified.
E)virtual,erect,and diminished.

Question 10

When an object is closer to a concave mirror than the mirror's focal point,the

A)magnification is less than one.
B)image distance is greater than the object distance.
C)magnification is equal to one.
D)image distance is negative.
E)image is inverted.

Question 11

An object is placed 4.24 cm in front of a concave mirror that has a radius of curvature of 20.3 cm.The image is located

A)12.1 cm in front of the mirror.
B)12.1 cm behind the mirror.
C)7.62 cm behind the mirror.
D)16.9 cm behind the mirror.
E)16.9 cm in front of the mirror.

Question 12

The technical name for the type of image formed by a single plane mirror is

A)a real image.
B)an inverted image.
C)an enlarged image.
D)a focal image.
E)a virtual image.

Question 13

An object 0.50 cm high is 5.0 cm from a concave spherical mirror of focal length 20 cm.How high is the image and is it erect or inverted?

A)0.40 cm,inverted
B)0.67 cm,erect
C)0.50 cm,inverted
D)0.67 cm,inverted
E)0.40 cm,erect

Question 14

The image of an object located 10 cm from a concave spherical mirror of radius 10 cm is

A)real,inverted,and magnified.
B)real,inverted,and diminished.
C)real,inverted,and the same size.
D)virtual,erect,and magnified.
E)virtual,erect,and diminished.

Question 15

A concave spherical mirror has a radius of curvature of 50 cm.The image of an object located 35 cm in front of the mirror is

A)real,inverted,magnified 2.5 times,and 87.5 cm from the mirror.
B)real,erect,magnified 2.5 times,and 87.5 cm from the mirror.
C)virtual,erect,magnified 3.3 times,and 117 cm from the mirror.
D)real,inverted,magnified 3.3 times,and 117 cm from the mirror.
E)real,inverted,diminished 0.42 times,and 14.6 cm from the mirror.

Question 16

When an object is farther from a concave mirror than twice the mirror's focal length,the

A)magnification is less than one.
B)image is inverted.
C)image distance is less than the object distance.
D)image is real.
E)All of these are correct.

Question 17

An object 25 cm from a convex mirror is observed to produce an image 13.6 cm behind the mirror.What is the focal length of the mirror?

A)8.8 cm
B)-8.8 cm
C)30 cm
D)-30 cm
E)-60 cm

Question 18

When an object is closer to a convex mirror than the mirror's focal point,the

A)magnification is less than one.
B)image distance is greater than the object distance.
C)magnification is equal to one.
D)image is real.
E)image is inverted.

Question 19

Two plane mirrors are arranged so that the reflecting surfaces face each other and are parallel.The mirrors are located at x = 2 m and x = 2 m.An object is located at x = 1 m.The second image from the left mirror is located at

A)-4 m
B)-5 m
C)-6 m
D)-8 m
E)None of the above.

Question 20

An object is placed between 2f and infinity in front of a concave mirror of focal length f.The image is located

A)behind the mirror,between 2f and the mirror.
B)behind the mirror,between 2f and infinity.
C)in front of the mirror,between the mirror and f.
D)in front of the mirror,between f and the center of curvature.
E)in front of the mirror,between the center of curvature and infinity.

Question 21

A positive lens has a focal length f.The image is the same size as the object when

A)the object is at the focal point.
B)the image is on the opposite side of the lens from the object and is the same distance from the lens as the object.
C)the image is on the same side of the lens as the object and is the same distance from the lens as the object.
D)The image can never be the same size as the object.
E)None of these is correct.

Question 22

A circular coin is 33.3 cm from a concave spherical mirror.(Assume the coin is on the optical axis.)The image of the coin is produced 10.0 cm from the mirror and on the same side as its real position.If the coin is moved to a position 23.3 cm from the mirror,calculate how far from the mirror the new image is:

A)13.7 cm
B)10.0 cm
C)15.1 cm
D)8.35 cm
E)11.5 cm

Question 23

A real object is 42 cm from a negative lens with f = -21 cm.The image is

A)real and 14 cm from the lens.
B)real and 42 cm from the lens.
C)virtual and 42 cm from the lens.
D)virtual and 21 cm from the lens.
E)virtual and 14 cm from the lens.

Question 24

When you stand in water up to your knees,your feet appear

A)closer than usual.
B)farther away than usual.
C)at the same location as usual.
D)To answer this you must know your height and the depth of the water.
E)To answer this you must know the index of refraction of water.

Question 25

Two parallel mirrors are a distance d apart.An object is placed 1.0 inch in front of the right-hand mirror.After 5 reflections,with the first reflection from the right-hand mirror,an image is located 17 inches behind the right-hand mirror.Calculate the distance between the mirrors.

A)5.3 in
B)3.2 in
C)6.0 in
D)4.0 in
E)3.6 in

Question 26

An object is located 3 cm in front of a converging lens of focal length 2 cm.A diverging lens of -6 cm focal length is placed 3 cm on the other side of the converging lens.What is the final image distance with respect to the diverging lens?

A) $\infty$
B)2 cm
C)-2 cm
D)6 cm
E)-6 cm

Question 27

An object 2 cm high is placed 20 cm from a thin convex lens that has a focal length of 10 cm.Which of the following statements describes the image formed?

A)It is 2 cm high.
B)It is 20 cm from the lens.
C)It is inverted.
D)It is real.
E)All of these are correct.

Question 28

A positive lens of focal length 40 cm is placed 20 cm behind a negative lens of focal length -80 cm.An object is placed 240 cm in front of the negative lens.The final image distance relative to the positive lens is

A)-40 cm
B)56 cm
C)-56 cm
D)80 cm
E)-80 cm

Question 29

A thin converging lens made of Crown glass (n = 1.517)is flat on one side and has a radius of curvature of 50 cm on the other side.An object is placed 45.0 cm to the left of this lens.Where is the image?

A)120 cm to the right of the lens
B)31 cm to the left of the lens
C)31 cm to the right of the lens
D)84 cm to the right of the lens
E)84 cm to the left of the lens

Question 30

A real object in front of a concave spherical mirror can produce an image that is

A)virtual,inverted,and magnified.
B)real,erect,and magnified.
C)diminished,erect,and virtual.
D)magnified,erect,and virtual.
E)diminished,real,and erect.

Question 31

The lens of a slide projector has a focal length of +12.0 cm.A slide 12.6 cm to the left of the lens forms the object for the lens.The screen should be placed

A)25 cm to the left of the lens.
B)25 cm to the right of the lens.
C)250 cm to the left of the lens.
D)250 cm to the right of the lens.
E)390 cm to the right of the lens.

Question 32

Which of the following statements is false?

A)The image produced by a diverging lens is always virtual,upright,and reduced in size.
B)The image produced by a converging lens can be virtual,upright,and magnified in size.
C)The image produced by a converging lens can never virtual,upright,and reduced in size.
D)To produce a real image,an object has to be place further away than the focal point of a converging lens.
E)The image produced by a converging lens cannot be real,inverted,and reduced in size.

Question 33

To project an image onto a screen using a lens,

A)the lens must be diverging and the object must be farther from the lens than the second focal point.
B)the lens must be converging and the object must be between the first focal point and the lens.
C)the lens must be diverging and the image must be farther from the lens than the second focal point.
D)the lens must be converging and the object must be farther from the lens than the first focal point.
E)the lens must be diverging and the object must be between the first focal point and the lens.

Question 34

A lens forms an erect image of a real object.The image is twice the size of the object and appears to be 40 cm from the lens.Determine the power of the lens in diopters (D).

A)There is not sufficient information.
B)-2.5 D
C)+2.5 D
D)+7.5 D
E)None of these is correct.

Question 35

A real object is 42.1 cm from a negative lens that has a focal length of 25.6 cm.The object is 2.45 mm high.The height and orientation of the image are

A)3.8 mm and inverted.
B)0.93 mm and erect.
C)6.4 mm and erect.
D)0.38 mm and erect.
E)None of these is correct.

Question 36

A positive lens has a focal length f.The only way to get a magnification of -1 is to

A)place a real object at the focal point.
B)place a real object at a distance 2f from the lens.
C)place a virtual object at a distance 2f from the lens.
D)Magnifications can never be negative.
E)None of these is correct.

Question 37

A real object is 30 cm from a negative lens that has a focal length f = -20 cm.The image is

A)virtual and 30 cm from the lens.
B)real and 12 cm from the lens.
C)virtual and 12 cm from the lens.
D)real and 20 cm from the lens.
E)None of these is correct.

Question 38

A circular coin is 33.3 cm from a concave spherical mirror.(Assume the coin is on the optical axis.)The image of the coin is produced 23.3 cm towards the mirror from its real position.Calculate the focal length of the mirror.

A)15.4 cm
B)7.69 cm
C)13.7 cm
D)27.4 cm
E)10.0 cm

Question 39

A cat is watching a goldfish in a spherical fishbowl of radius 15.0 cm.The goldfish is 5.00 cm from the side of the bowl nearest the cat.How far from the side of the bowl does the fish appear to be to the cat? (For water,n = 1.33.)

A)7.5 cm
B)4.5 cm
C)4.1 cm
D)3.5 cm
E)2.5 cm

Question 40

The clear water of a lake is 1.5 m deep at the end of a dock.You look directly down from the end of the dock and see a rock on the bottom of the lake.How far below the surface does the rock appear to be? (For water,n = 1.33.)

A)2.0 m
B)1.5 m
C)1.1 m
D)0.75 m
E)1.8 m

Question 41

The focal length of a converging lens that projects the image of a lamp,magnified 4 times,onto a screen 3.05 m from the lamp is approximately

A)11.6 cm
B)48.8 cm
C)-11.6 cm
D)2.04 m
E)19.2 cm

Question 42

An object 5.0 cm tall is placed 15 cm in front of a converging lens of focal length 30 cm.The final image size is

A)2.5 cm
B)3.3 cm
C)5.0 cm
D)7.5 cm
E)10 cm

Question 43

In order for a lens to produce a real image,the light rays from the object

A)must actually be focused at the image location
B)come to a stop at the image location.
C)appear to be focused at the image location.
D)must first travel in a straight line parallel to the axis.
E)will always be focused at the image location.

Question 44

A 6-cm-high candle is placed in front of a converging lens with a focal length of magnitude 30 cm.If the image distance is +50 cm,then find the image height of the candle and whether it is upright or inverted.

A)4.0 cm upright
B)3.3 cm upright
C)3.3 cm inverted
D)4.0 cm inverted
E)None of these is correct.

Question 45

The optical path for visible light in a lens is

A)the same as the geometrical path.
B)the same no matter what portion of the lens it passes through.
C)the same as the optical path for ultraviolet.
D)independent of the material of which the lens is constructed.
E)is increased when the index of refraction is increased.

Question 46

A concave (diverging)lens can produce an image that is

A)virtual,inverted,and magnified.
B)real,erect,and magnified.
C)diminished,erect,and virtual.
D)magnified,erect,and virtual.
E)diminished,real,and erect.

Question 47

A converging lens and a screen are so arranged that an image of the sun falls on the screen.The distance from the lens to the screen is

A)the focal length.
B)the object distance.
C)the magnifying power.
D)one-half the radius of curvature of one of the lens faces.
E)the average radius of curvature of the two lens faces.

Question 48

A real object is placed 9.00 cm from a converging lens that has a focal length of 24.0 cm.The image is

A)0.119 cm from the lens,real,and smaller than the object.
B)0.119 cm from the lens,virtual,and smaller than the object.
C)14.4 cm from the lens,real,and enlarged.
D)14.4 cm from the lens,virtual,and enlarged.
E)11.7 cm from the lens,virtual,and enlarged.

Question 49

A diverging lens has a focal length of magnitude 20 cm.An object is placed 10 cm in front of the diverging lens.Calculate the magnitude of the distance of the image to the lens.

A)10 cm
B)20 cm
C)6.7 cm
D)5.2 cm
E)8.5 cm

Question 50

The objective of a certain lens system is a double-convex lens of 10.2 cm focal length; the eyepiece is a lens of 15.2 cm focal length and is placed 25.4 cm behind the objective.When an object is 30.5 cm in front of the objective,how far is the image from the eyepiece?

A)44.2 cm
B)30.5 cm
C)5.08 cm
D)22.1 cm
E)61.0 cm

Question 51

A diverging lens has a focal length of magnitude 20 cm.An object is placed 10 cm in front of the diverging lens.Calculate the magnification of the image and whether it is upright or inverted.

A)0.67 upright
B)0.52 upright
C)0.67 inverted
D)1.5 upright
E)0.85 inverted

Question 52

A double-convex lens is made of glass of refractive index 1.50.The radii of curvature of the surfaces are 10 cm and 20 cm.The focal length of this lens is

A)4.45 cm
B)13.3 cm
C)-13.3 cm
D)40 cm
E)-40 cm

Question 53

A 6-cm-high candle is placed in front of a converging lens with a focal length of magnitude 30 cm.If the image distance is +50 cm,then find the object distance to the lens.

A)75 cm
B)50 cm
C)60 cm
D)80 cm
E)None of these is correct.

Question 54

An object is located 4 cm from a converging lens of focal length 3 cm.The magnitude of the magnification of the image is

A)3
B)4
C)9
D)12
E)16

Question 55

An object is placed 5 m in front of a converging lens of focal length 11 cm.A diverging lens with focal length 11 cm is placed 6 cm behind the converging lens.Calculate the position of the final image produced by the two-lens system and state if this final image is real or virtual.

A)5.3 cm real
B)10 cm real
C)-5.3 cm virtual
D)-7.5 cm virtual
E)7.5 cm real

Question 56

A concave-convex lens of flint glass has radii of 12 cm and 10 cm,respectively,and an index of refraction of 1.60.The focal length of this lens is

A)100 cm
B)-100 cm
C)9.1 cm
D)-9.1 cm
E)14.5 cm

Question 57

To locate the position of an image formed by a lens using ray tracing,one needs to

A)have rays coming from multiple points of the object and find an intersect point.
B)have rays coming from one point of the object and find an intersect point.
C)have a ray going parallel to the axis.
D)have a ray pass through the edge of the lens without bending.
E)None of the above will give the location of the image.

Question 58

An object is placed to the left of a thin converging lens with a focal length of 8 cm.A real and inverted image is formed 13.3 cm to the right of the lens.What is the distance of the object from the lens?

A)20.1 cm
B)13.3 cm
C)5.00 cm
D)0.20 cm
E)21.3 cm

Question 59

An object is placed 200 cm from a screen.When a converging lens is placed between the object and screen at a distance of 160 cm from the object,an image is formed on the screen.Without moving the object or screen,an image can also be formed on the screen when the distance from the object to the lens is

A)8 cm
B)16 cm
C)20 cm
D)32 cm
E)40 cm

Question 60

When a human eye that has a power of +60 D is fitted with a contact lens of -10 D,the equivalent lens combination is

A)diverging and of focal length 2 cm.
B)converging and of focal length 50 cm.
C)converging and of focal length 2 cm.
D)focal length 0.02 cm.
E)focal length 0.2 cm.

Question 61

If the near point of your eye is 80.0 cm,what power of reading glasses should you use to bring your near point to 25.0 cm?

A)-1.25
B)4.00
C)36.5
D)1.25
E)27.5

Question 62

Which type of aberration can be eliminated using mirrors instead of lenses?

A)chromatic aberration
B)spherical aberration
C)coma aberration
D)astigmatism
E)all the aberrations

Question 63

Your left eye can focus on objects a great distance away but cannot focus on objects that are closer than 125 cm to it.The power of the lens in diopters that you need for normal near vision (25 cm)is

A)+0.8 diopters
B)+3.2 diopters
C)+4.0 diopters
D)-4.0 diopters
E)None of these is correct.

Question 64

A stamp collector with a normal near point (25 cm)needs a magnifying power of 10 to examine her stamps.What power of magnifying glass should she buy?

A)0.40 diopters
B)2.5 diopters
C)10 diopters
D)40 diopters
E)25 diopters

Question 65

Your hypermetropic eye cannot focus on objects that are more than 225 cm from it.The power in diopters of the lens you need for distinct distant vision is

A)+2.25 diopters
B)+4.4 $\times$ 10^-3 diopters
C)+3.6 diopters
D)-0.44 diopters
E)None of these is correct.

Question 66

Your near point is x_np,and you're using a lens of focal length x_np/5 as a simple magnifier.What magnification do you obtain?

A)10
B)50
C)0.1
D)0.2
E)5

Question 67

Your myopic eye cannot focus on objects that are more than 16.5 cm away or closer than 4.5 cm.When you put on glasses for normal distant vision,your new near point is

A)3.5 cm
B)16.5 cm
C)6.2 cm
D)10.5 cm
E)None of these is correct.

Question 68

Your farsighted boyfriend requires lenses with a power of 1.85 diopters to read comfortably from a book that is 25.0 cm from his eyes.What is his near point without the lenses?

A)54.1 cm
B)4.00 cm
C)46.5 cm
D)42.9 cm
E)36.2 cm

Question 69

Your nearsighted instructor cannot focus clearly on objects more distant than 150 cm from her eyes.What power lenses are required for her to see distant students clearly?

A)1.5
B)0.15
C)0.67
D)-0.67
E)-1.5

Question 70

A typical farsighted person requires

A)glasses with converging lenses to drive.
B)glasses with diverging lenses to drive.
C)glasses with converging lenses to read.
D)glasses with diverging lenses to read.
E)no glasses to read.

Question 71

Your near point is 25.0 cm,and you're using a 50-diopter lens as a simple magnifier.What magnification do you obtain?

A)12.5
B)2
C)50
D)10
E)15.6

Question 72

Your farsighted girlfriend requires lenses with a power of 1.67 diopters to read comfortably from a book that is 25.0 cm from her eyes.What is her near point without the lenses?

A)17.6 cm
B)4.00 cm
C)59.9 cm
D)42.9 cm
E)36.2 cm

Question 73

Your nearsighted coach cannot focus clearly on objects more distant than 50 cm from his eye.What power lenses are required for him to follow the flight of a batted ball?

A)50
B)-2.0
C)0.67
D)-0.67
E)2.0

Question 74

A farsighted person uses glasses to read.The person then sees _____ print that appears _____ than is actually the case.

A)larger; closer
B)larger; farther away
C)smaller; closer
D)smaller; farther away
E)actual sized; farther away

Question 75

A spherical mirror exhibits

A)both chromatic and spherical aberrations.
B)neither chromatic nor spherical aberration.
C)spherical but not chromatic aberration.
D)chromatic but not spherical aberration.
E)The type of aberration depends on the shape of the spherical surface.

Question 76

How much must the focal length of an eye change when an object,originally at 4.00 m,is brought to 40.0 cm from the eye?

A)0.13 cm
B)2.48 cm
C)2.35 cm
D)2.50 cm
E)0.19 cm

Question 77

An object is placed 20 cm to the left of a converging lens with a focal length of 8 cm.A second converging lens of focal length 12 cm is placed to the right of the first lens.If the final image of the combined lens system is virtual and 15 cm from the second lens,then calculate the distance between the two lenses.

A)73.3 cm
B)46.7 cm
C)60.0 cm
D)6.63 cm
E)20.0 cm

Question 78

How much must the focal length of an eye change when an object,originally at 5.00 m,is brought to 30.0 cm from the eye?

A)0.13 cm
B)2.31 cm
C)2.35 cm
D)0.18 cm
E)2.49 cm

Question 79

For a myopic eye that cannot focus on objects more than 25 cm in front of it,the power in diopters of the lens needed for distinct distant vision is

A)+25 diopters
B)+4.0 diopters
C)-4.0 diopters
D)-2.5 diopters
E)None of these is correct.

Question 80

The theoretical limit to the sharpness of focus of a lens system is determined by

A)spherical aberration limitations.
B)chromatic aberration limitations.
C)astigmatic limitations.
D)diffraction limitations.
E)the relative smoothness of the lens surface.