Question 1

What is the near point of a farsighted person who can read a newspaper held 25 cm from his eyes when he wears 3.33 diopters glasses?

Accepted Answer

A)  1.5 m
B)  0.50 m
C)  1.9 m
D)  0.75 m
E)  0.60 mF) A) and E)
G) A) and D)

Question 2

A nearsighted person has a far point that is 4.2 m from his eyes. What focal length lenses must he use in his contact lenses to allow him to focus on distant objects?

Accepted Answer

A)  -4.2 m
B)  4.2 m
C)  -5.2 m
D)  5.2 m
E)  4.8 mF) B) and E)
G) A) and C)

Question 3

John is nearsighted and cannot see things beyond 90 cm from his eyes. What is the refractive power of the contact lenses that will enable him to see distant objects clearly?

Accepted Answer

A)  +1.1 diopters
B)  -1.1 diopters
C)  -1.7 diopters
D)  -2.2 diopters
E)  +2.2 dioptersF) C) and E)
G) B) and E)

Question 4

The length of a telescope is 1.60 m and it has a magnification of 60.0. What is the focal length of the eyepiece?

Accepted Answer

A)  2.62 cm
B)  60.0 cm
C)  100 cm
D)  1.16 cm
E)  96.0 cmF) D) and E)
G) C) and E)

Question 5

A lens of focal length 20 cm has an object of height 3.0 cm placed 100 cm in front of it. The image formed is

Accepted Answer

A)  upright and smaller than the object.
B)  inverted and smaller than the object.
C)  inverted and larger than the object.
D)  upright and larger than the object.
E)  upright and the same size as the object.F) A) and D)
G) B) and E)

Question 6

John is nearsighted and cannot see things beyond 110 cm from his eyes. What is the focal length of the contact lenses that will enable him to see distant objects clearly?

Accepted Answer

A)  +50 cm
B)  -50 cm
C)  -110 cm
D)  +110 cm
E)  -30 cmF) C) and D)
G) A) and E)

Question 7

A convex lens has a focal length f. An object is placed between infinity and 2f from the lens on its axis. The image formed is located

Accepted Answer

A)  at a distance greater than 2f from the lens.
B)  at 2f.
C)  between f and 2f.
D)  at f.
E)  between the lens and f.F) A) and D)
G) B) and D)

Question 8

What is the focal length of a pair of contact lenses that will allow a person with a near point of 125.0 cm to read a newspaper held 25.0 cm from his eyes?

Accepted Answer

A)  -100 cm
B)  -31.3 cm
C)  10.2 cm
D)  20.8 cm
E)  31.3 cmF) A) and D)
G) A) and C)

Question 9

A light ray, traveling parallel to the axis of a thin concave lens, strikes the lens near its midpoint. After traveling though the lens, this ray emerges traveling obliquely to the axis of the lens

Accepted Answer

A)  such that it never crosses the axis.
B)  crossing the axis at a point equal to twice the focal length.
C)  crossing the axis at a point equal to one-half the focal length.
D)  passing between the lens and its focal point.
E)  passing through the focal point.F) C) and D)
G) None of the above

Question 10

A magnifying lens has a focal length of 10 cm. A person has a near point of 25 cm.
(a) What is the magnification of the lens for that person when their eyes are focused at infinity?
(b) What is the magnification of the lens for that person when their eyes are focused at their near point?

Accepted Answer

The answer of A magnifying lens has a focal length...

Question 11

A magnifying glass produces a virtual image.

Accepted Answer

A) True 
 B)False

Question 12

An object is placed 100 cm in front of a lens of focal length 20 cm. A second lens is placed 15 cm past the first lens. The second lens has a focal length of 40 cm. The final image

Accepted Answer

A)  is real and upright.
B)  is virtual and upright.
C)  is real and inverted.
D)  is virtual and inverted.
E)  cannot be determined with the information given.F) A) and D)
G) B) and C)

Question 13

Which one of the following is a characteristic of a compound microscope?

Accepted Answer

A)  The objective is a diverging lens.
B)  The eyepiece is a diverging lens.
C)  The final image is real.
D)  The image formed by the objective is virtual.
E)  The image formed by the objective is real.F) A) and B)
G) All of the above

Question 14

The focal length of a magnifying glass is 15 cm. If the near point of a person is 25 cm, what is the magnification of this glass for this person when his eyes are focused at infinity?

Accepted Answer

A)  1.7
B)  2.7
C)  3.7
D)  4.7
E)  5.7F) B) and D)
G) A) and B)

Question 15

What is the maximum possible magnification of the converging lens of focal length 5 cm?

Accepted Answer

A)  2
B)  3
C)  4
D)  5
E)  6F) B) and E)
G) C) and D)

Question 16

A convex lens has a focal length f. An object is placed at f on the axis. The image formed is located

Accepted Answer

A)  at infinity.
B)  between 2f and infinity.
C)  at 2f.
D)  between f and 2f.
E)  between the lens and f.F) B) and C)
G) A) and E)

Question 17

A simple compound microscope provides large magnification by employing

Accepted Answer

A)  a short focal length objective and a short focal length eyepiece.
B)  a short focal length objective and a long focal length eyepiece.
C)  a long focal length objective and a short focal length eyepiece.
D)  a long focal length objective and a long focal length eyepiece.E) C) and D)
F) All of the above

Question 18

A lens of focal length 25 cm is placed 50 cm from an object. On the opposite side of the lens at a distance of 50 cm is a plane mirror. Where is the final image formed?

Accepted Answer

A)  50 cm from the lens on the object side
B)  35 cm behind the mirror
C)  35 cm in front of the mirror
D)  50 cm from the lens on the mirror side
E)  35 cm from the lens on the object sideF) A) and D)
G) C) and D)

Question 19

Farsightedness can usually be corrected with

Accepted Answer

A)  cylindrical lenses.
B)  achromatic lenses.
C)  diverging lenses.
D)  converging lenses.
E)  spherical lenses.F) All of the above
G) A) and D)

Question 20

The near point of a normal human eye is infinity.

Accepted Answer

A) True 
 B)False

Exam 33: Lenses and Optical Instruments

A magnifying lens has a focal length of 10 cm. A person has a near point of 25 cm. (a) What is the magnification of the lens for that person when their eyes are focused at infinity? (b) What is the magnification of the lens for that person when their eyes are focused at their near point?

Correct AnswerverifiedShow Answer

A simple compound microscope provides large magnification by employing

Correct AnswerverifiedShow Answer

What is the maximum possible magnification of the converging lens of focal length 5 cm?

Correct AnswerverifiedShow Answer

What is the focal length of a pair of contact lenses that will allow a person with a near point of 125.0 cm to read a newspaper held 25.0 cm from his eyes?

Correct AnswerverifiedShow Answer

A nearsighted person has a far point that is 4.2 m from his eyes. What focal length lenses must he use in his contact lenses to allow him to focus on distant objects?

Correct AnswerverifiedShow Answer

What is the near point of a farsighted person who can read a newspaper held 25 cm from his eyes when he wears 3.33 diopters glasses?

Correct AnswerverifiedShow Answer

The focal length of a magnifying glass is 15 cm. If the near point of a person is 25 cm, what is the magnification of this glass for this person when his eyes are focused at infinity?

Correct AnswerverifiedShow Answer

A light ray, traveling parallel to the axis of a thin concave lens, strikes the lens near its midpoint. After traveling though the lens, this ray emerges traveling obliquely to the axis of the lens

Correct AnswerverifiedShow Answer

The length of a telescope is 1.60 m and it has a magnification of 60.0. What is the focal length of the eyepiece?

Correct AnswerverifiedShow Answer

A lens of focal length 25 cm is placed 50 cm from an object. On the opposite side of the lens at a distance of 50 cm is a plane mirror. Where is the final image formed?

Correct AnswerverifiedShow Answer

Which one of the following is a characteristic of a compound microscope?

Correct AnswerverifiedShow Answer

John is nearsighted and cannot see things beyond 110 cm from his eyes. What is the focal length of the contact lenses that will enable him to see distant objects clearly?

Correct AnswerverifiedShow Answer

A magnifying glass produces a virtual image.

Correct AnswerverifiedShow Answer

A convex lens has a focal length f. An object is placed between infinity and 2f from the lens on its axis. The image formed is located

Correct AnswerverifiedShow Answer

Farsightedness can usually be corrected with

Correct AnswerverifiedShow Answer

A lens of focal length 20 cm has an object of height 3.0 cm placed 100 cm in front of it. The image formed is

Correct AnswerverifiedShow Answer

An object is placed 100 cm in front of a lens of focal length 20 cm. A second lens is placed 15 cm past the first lens. The second lens has a focal length of 40 cm. The final image

Correct AnswerverifiedShow Answer

The near point of a normal human eye is infinity.

Correct AnswerverifiedShow Answer

John is nearsighted and cannot see things beyond 90 cm from his eyes. What is the refractive power of the contact lenses that will enable him to see distant objects clearly?

Correct AnswerverifiedShow Answer

A convex lens has a focal length f. An object is placed at f on the axis. The image formed is located

Correct AnswerverifiedShow Answer

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