Deck 23: Mirrors and Lenses

Question 1

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

Answer 1

virtual,upright and magnification greater than one

Question 2

A concave mirror forms a real image at 29.0 cm from the mirror surface along the principal axis.If the corresponding object is at a 10.0-cm distance,what is the mirror's focal length?

A) 19.0 cm
B) 39.0 cm
C) 13.4 cm
D) 7.44 cm
E) ​15.3 cm

Answer 2

7.44 cm

Question 3

If a virtual image is formed 15.0 cm along the principal axis from a convex mirror of focal length -20.0 cm,how far is the object from the mirror?

A) 60.0 cm
B) 15.0 cm
C) 5.00 cm
D) 20.0 cm
E) ​7.00 cm

Answer 3

60.0 cm

Question 4

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 5

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 6

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 7

A convex mirror with a focal length of -17 cm forms an image 12 cm behind the surface.If the object height is 1.0 cm what is the image height?

A) 0.29 cm
B) 3.4 cm
C) 2.40 cm
D) 1.0 cm
E) ​0.71 cm

Question 8

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 9

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 10

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.

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

If a virtual image is formed along the principal axis 9 cm from a concave mirror with the focal length 16 cm,what is the object distance from the mirror?

A) 7.0 cm
B) 21 cm
C) 17 cm
D) 5.8 cm
E) ​4.9 cm

Question 13

An object placed 18.0 cm from a concave mirror produces a real image 16.0 cm from the mirror.If the object is now moved to a new position 22.0 cm from the mirror,where is the new image located as measured from the mirror?

A) 8.5 cm
B) 13.8 cm
C) 6.1 cm
D) 19.6 cm
E) ​20.0 cm

Question 14

The real image of an object is located 28.0 cm away from a concave mirror,which has a focal length of 10.0 cm.How far is the object from the mirror?

A) 18.0 cm
B) 20.0 cm
C) 6.4 cm
D) 15.6 cm
E) ​28.0 cm

Question 15

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 16

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

A) 6 ft
B) 7 ft
C) 12 ft
D) 3 ft
E) ​24 ft

Question 17

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 18

A woman looking in a makeup mirror sees her face at twice its actual size and right-side up.If she is 31.0 cm from the mirror,what is its focal length?

A) 20.7 cm
B) 62.0 cm.
C) 15.5 cm
D) 62.0 cm
E) ​31.0 cm

Question 19

A convex mirror with focal length of -26 cm forms an image 15 cm behind the surface.Where is the object located as measured from the surface?

A) 9.1 cm
B) 11 cm
C) 9.5 cm
D) 35 cm
E) ​15 cm

Question 20

An object is held at a distance of 23 cm from a convex mirror creating an image that is 1/4 the object size.What is the focal length of the mirror?

A) -7.7 cm
B) 17 cm
C) -4.6 cm
D) -4.8 cm
E) ​31 cm

Question 21

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 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 3 cm.What is the ratio of the indices of refraction of these fluids?

A) n1/n2 = 3/5
B) n1/n2 = 5/3
C) n1/n2 =
D) n1/n2 =
E) ​More information is needed to find the ratio.

Question 23

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 24

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 true?

A) The focal length of the mirror is 30 cm.
B) The image is real.
C) There is not enough information to select the correct answer.
D) This is the only false statement.

Question 25

Ron fills a beaker with glycerin (n = 1.473)to a depth of 3.0 cm.If he looks straight down through the glycerin surface,he will perceive the liquid to be what apparent depth?

A) 4.4 cm
B) 3.0 cm
C) 2.0 cm
D) 2.5 cm
E) ​3.6 cm

Question 26

An object 6 cm high is placed 18 cm in front of a mirror.What type of mirror and what radius of curvature is needed for an image that is upright and 16 cm tall?

A) Concave,R = 58 cm
B) Concave,R = 7 cm
C) Convex,R = -7 cm
D) Convex,R = -26 cm
E) ​Concave,R = 29 cm

Question 27

A goldfish is swimming in water (n = 1.33)inside a spherical plastic bowl of index of refraction 1.33.If the goldfish is 12 cm from the front wall of the 23-cm radius bowl,where does the goldfish appear to an observer in front of the bowl?

A) 7.99 cm behind the plastic
B) 19.3 cm behind the plastic
C) 13.6 cm behind the plastic
D) 10.4 cm behind the plastic
E) ​13.6 cm behind the plastic

Question 28

A candle is 55.0 cm in front of a convex spherical mirror of radius of curvature 56.0 cm.What are the image distance and the magnification,respectively?

A) -18.6 cm,+ 0.337
B) -27.7 cm,- 2.964
C) -1.0 cm,+ 0.331
D) -3.51 cm,+ 2.964
E) ​18.6 cm,- 0.337

Question 29

A 2.5 cm tall object is placed along the principal axis of a thin convex lens of 16 cm focal length.If the object distance is 29 cm,which of the following best describes the image distance and height,respectively?

A) 10 cm and 5.6 cm
B) 36 cm and 3.1 cm
C) 10 cm and 8.7 cm
D) 24 cm and 5.6 cm
E) ​69 cm and 2.0 cm

Question 30

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 31

A glass block,for which n = 1.52,has a blemish located 5.0 cm from one surface.At what distance from that surface does the image of the blemish appear to the outside observer?

A) 7.6 cm
B) 3.3 cm
C) 6.2 cm
D) 4.1 cm
E) ​5.0 cm

Question 32

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 33

An object is 16.0 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) - 0.111
B) - 0.556
C) + 0.111
D) + 0.556
E) ​+ 0.333

Question 34

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 35

A solid glass sphere with a radius of 8.00 cm and index of refraction of 1.50 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) 1.86 cm
B) 2.50 cm
C) 2.96 cm
D) 2.42 cm
E) ​1.67 cm

Question 36

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 37

An object of length 3.20 cm is inside a plastic block with index of refraction 1.30.If the object is viewed from directly above,what is the length of its image?

A) 3.20 cm
B) 4.16 cm
C) 2.46 cm
D) 2.81 cm
E) ​1.89 cm

Question 38

Atmospheric refraction of light rays is responsible for:

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

Question 39

A container is filled with fluid 1,and the apparent depth of the fluid is 8.00 cm.The container is next filled with fluid 2,and the apparent depth of this fluid is 6.00 cm.If the index of refraction of the first fluid is 1.30,what is the index of refraction of the second fluid?

A) 1.73
B) 2.28
C) 1.50
D) 1.13
E) ​More information is needed to find the value.

Question 40

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 41

A projector lens is needed to form an image on a screen 10 times the size of its corresponding object.The screen is located 6.0 m from the lens.What is the required focal length of the lens?

A) 0.60 m
B) 5.5 m
C) 0.55 m
D) 0.30 m
E) ​0.67 m

Question 42

For a converging lens with two curved surfaces,the radius of curvature for both surfaces is 11 cm.If the focal length is 20 cm,what must the index of refraction be?

A) 1.3
B) 1.6
C) 2.6
D) 1.7
E) ​1.5

Question 43

Two thin lenses with 15.0-cm focal lengths at are mounted at opposite ends of a 60.0-cm long tube.An object is located 66.0 cm from one end of the tube.How far from the opposite end is the final image?

A) 18.5 cm
B) 23.8 cm
C) 11.4 cm
D) 40.6 cm
E) ​66.0 cm

Question 44

An object is placed at a distance of 58 cm from a thin lens along the axis.If a real image forms at a distance of 39 cm from the lens,on the opposite side from the object,what is the focal length of the lens?

A) 23 cm
B) 49 cm
C) 38 cm
D) 120 cm
E) ​37 cm

Question 45

What is the image distance of an object 1.30 m in front of a converging lens of focal length 20.0 cm?

A) + 17.3 cm
B) -1.39 cm
C) + 23.6 cm
D) + 110 cm
E) ​+ 4.2 cm

Question 46

An object is placed at a distance of 33 cm from a thin convex lens along its axis.The lens has a focal length of 16 cm.What are the values,respectively,of the image distance and magnification?

A) 11 cm and + 1.06
B) 31 cm and - 0.515
C) 17 cm and - 0.941
D) 31 cm and - 0.941
E) ​17 cm and - 0.515

Question 47

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

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

Question 48

A converging lens with two convex surfaces has a front surface with radius of curvature of 14.0 cm;the back surface has radius of curvature of 24.0 cm,and it is made from material with an index of refraction of 2.90.What is the focal length of the lens?

A) 4.7 cm
B) 17.7 cm
C) −17.7 cm
D) 3.0 cm
E) 11.6 cm

Question 49

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 50

Two convex thin lenses with focal lengths 9.0 cm and 24.0 cm are aligned on a common axis,running left to right,the 9-cm lens being on the left.A distance of 24.0 cm separates the lenses.An object is located at a distance of 14.0 cm to the left of the 9-cm lens.Where will the final image appear as measured from the 24-cm lens?

A) - 1.26 cm
B) + 81.1 cm
C) + 1.26 cm
D) + 49.8 cm
E) ​- 81.1 cm

Question 51

A contact lens is made of plastic with an index of refraction 2.70.The lens has an outer radius of curvature of + 3.3 cm and an inner radius of curvature of + 4.5 cm.What is its focal length?

A) -7.3 cm
B) +4.6 cm
C) +1.1 cm
D) +7.3 cm
E) -1.1 cm

Question 52

An object,located 96 cm from a concave lens,forms an image 34 cm from the lens on the same side as the object.What is the focal length of the lens?

A) -25 cm
B) -130 cm
C) -53 cm
D) -124 cm
E) ​-22 cm

Question 53

Sally places an object 8.0 cm from a thin convex lens along its axis.The lens has a focal length of 19.0 cm.What are the respective values of the image distance and magnification?

A) -13.8 cm and + 1.7
B) 13.8 cm and + 1.7
C) 5.6 cm and + 0.7
D) -13.8 cm and -1.7
E) ​13.8 cm and -1.7

Question 54

Two thin lenses with focal lengths 23.0 cm and 33.0 cm are placed in contact in an orientation so that their optic axes coincide.What is the focal length of the two in combination? (Hint: A thin lens is one whose thickness is negligible).

A) 13.6 cm
B) 28.0 cm
C) 75.9 cm
D) 56.0 cm
E) ​7.0 cm

Question 55

For a diverging lens with one flat surface,the radius of curvature for the curved surface is 27.0 cm.What must the index of refraction be so that the focal length is -15.0 cm?

A) 0.56
B) 1.56
C) 2.80
D) 1.90
E) 1.80

Question 56

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 57

Two thin lenses,with focal lengths of 22.0 cm and -40.0 cm are placed in contact in an orientation so that their optic axes coincide.What is the focal length of the two in combination? {Hint: A thin lens is one whose thickness is negligible).

A) 14.2 cm
B) 62.0 cm
C) 18.0 cm
D) 48.9 cm
E) ​-48.9 cm

Question 58

An object and a screen are separated by 26.0 cm.A convex lens is placed between them,9.00 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) 6.69 cm
B) 19.1 cm
C) 5.88 cm
D) 13.8 cm
E) ​8.50 cm

Question 59

Ellen places an object 48.0 cm from a concave lens.If a virtual image appears 13.0 cm from the lens on the same side as the object,what is the focal length of the lens?

A) -10.2 cm
B) -17.8 cm
C) -20.7 cm
D) -35.0 cm
E) ​-30.5 cm

Question 60

Ansel places an object 23.0 cm from a thin convex lens along the axis.If a real image forms at a distance of 14.0 cm from the lens,what is the focal length of the lens?

A) 23.0 cm
B) 35.8 cm
C) 14.0 cm
D) 8.70 cm
E) ​9.0 cm

Question 61

An object is placed 45.0 cm to the right of a concave mirror with focal length 24.0 cm and -5.0 cm to the left of a lens with focal length -16.0 cm.Where is the image formed by both the mirror and the lens?

A) 6.67 cm to the right of the object
B) 6.67 cm to the right of the lens
C) 23.2 cm to the right of the lens
D) 7.91 cm to the right of the lens
E) ​23.2 cm to the left of the lens

Question 62

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 63

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 true?

A) The last image is inverted with regard to the original object.
B) The last image must be larger than the object.
C) The first image is virtual.
D) None of the above statements is true.

Question 64

A 80-cm focal length thin lens is placed in contact with one of 59.5 cm focal length.A 2.3 cm tall object is placed 55 cm in front of the combination.What is the size of the image?

A) 0.9 cm
B) 1.9 cm
C) 6.0 cm
D) 3.7 cm
E) ​1.4 cm

Question 65

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 66

Five thin lenses,each of focal length f,are placed in contact.What is the resulting focal length of the combination?

A) f
B) 5f
C) f/5
D) 5/f
E) ​5f/6

Question 67

A lens of 10.0-cm focal length is placed 29.0 cm to the right of the object and a mirror of focal length -20.0 cm is placed 49.0 cm to the right of the lens.Where is the image formed by the mirror?

A) 23.3 cm to the right of the mirror
B) 8.7 cm to the left of the mirror
C) 49.1 cm to the left of the lens
D) 12.6 cm to the right of the mirror
E) ​12.6 cm to the left of the mirror

Question 68

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 69

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 70

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 71

A concave mirror with focal length 17.0 cm is placed 38.0 cm to the left of the object.A convex lens of focal length 18.0 cm is placed 54.0 cm to the right of the object.Where is the image formed by both the mirror and the lens?

A) 13.9 cm to the right of the object
B) 25.5 cm to the right of the lens
C) 67.9 cm to the right of the object
D) 43.4 cm to the right of the lens
E) ​17.0 cm to the right of the lens

Question 72

A lens of 13.0-cm focal length is placed 29.0 cm to the right of the object and a mirror of focal length -19.0 cm is placed 39.6 cm to the right of the lens.Where is the final image formed?

A) 58.6 cm to the left of the lens
B) 5.0 cm to the left of the lens
C) 8.7 cm to the right of the mirror
D) 8.7 cm to the left of the mirror
E) ​58.6 cm to the right of the lens

Question 73

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 74

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 75

An object is placed 28 cm to the left of a lens of focal length 15 cm.24 cm to the right of this lens is a plane mirror.Where does the final image form?

A) 8 cm to the right of the mirror
B) 8 cm to the left of the mirror
C) 16 cm to the left of the lens
D) 32 cm to the left of the lens
E) 14​ cm to the left of the mirror

Question 76

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 77

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 78

A lens has a focal length of 41 cm in air.If this lens were immersed in water,what focal length would result? The index of refraction of the lens is 2.200 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) 75.6 cm
B) 22.2 cm
C) 125 cm
D) 67.7 cm
E) ​28.7 cm

Question 79

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 80

A 80-cm focal length thin lens is placed in contact with one of 59.2 cm focal length.An object is placed 51 cm in front of the combination.What is the image distance?

A) 20.0 cm
B) 191 cm
C) 42.0 cm
D) 102 cm
E) ​25.5 cm