1.
Compare two diverging lenses similar
except that lens B is rated at 20 diopters, whereas lens A is
rated at 10 diopters. The focal
length of lens B is
a. one-fourth
of the focal length of lens A.
b. one-half
of the focal length of lens A.
c. twice
the focal length of lens A.
d. four
times the focal length of lens A.
2. If a person's eyeball is too short
from front to back, the person is likely to suffer from
a. astigmatism.
b. spherical
aberration.
c. farsightedness.
d. nearsightedness.
3. In which of the following ways is
a camera different from the human eye?
a. The camera
always forms an inverted image, the eye does not.
b. The camera
always forms a real image, the eye does not.
c.
The camera utilizes a fixed focal
length lens, the eye does not for the camera, the image
magnification is greater than one, but for the eye
the magnification is less than one.
e. A camera
cannot focus on objects at infinity but the eye can.
4. Farsightedness can usually be corrected
with
a. cylindrical
lenses.
b. achromatic
lenses.
c. diverging
lenses.
d. converging
lenses.
5. Nearsightedness can usually be corrected
with
a. converging
lenses.
b. diverging
lenses.
c. achromatic
lenses.
d. cylindrical
lenses.
6. The principal refraction of light
by the eye occurs at the
a. cornea.
b. lens.
c. retina.
d.
iris.
7. A
near-sighted person has a far point of 18 cm. What
lens (in diopters) will allow this person
to see distant objects clearly?
a. +5.6
D
b. -5.6
D
c. +0.056
D
d. -0.056
D
8. The
near point of a farsighted person is 100 cm. She places
reading glasses close to her eyes,
and with them she can comfortably read a newspaper at
a distance of 25 cm. What lens power
is required?
a. +2.5
D
b. +3.0
D
c. +3.2
D
d. -2.0
D
9. What
power lens is needed to correct for farsightedness where the uncorrected
near point is
75 cm?
a. -2.7
D
b. +2.7
D
c. +5.3
D
d. None
of the above
10. A
person cannot see clearly objects more than 70.0 cm away.
What power of lens should be
prescribed if the glass is to be worn 1.00 cm in front
of the eye?
a. 1.45
D
b. -1.45D
c. 0.0145
D
d. -0.0145
D
11. The closest distance at which an
eye can see objects clearly is
a. the near
point
b. the far
point
c. nearsightness
d. farsightness
12. The longest distance at which an
eye can see objects clearly is
a. the near
point
b. the far
point
c. nearsightness
d. farsightness
13. A
nearsighted person wears glasses whose lenses have power of -0.15 D. What is the person's
far point if the glasses are very close to the eyes?
a. 1.5 m
b. 3.3 m
c. 6.0 m
d. 6.7 m
14. If a farsighted person has a near
point of 120 cm, what power of glasses should be prescribed?
a. 0.83
D
b. -0.83
D
c. 3.2 D
d. -3.2
D
15. A
magnifying lens has a focal length of 10 cm. A person
has a near point of 25 cm. What is
the
magnification of the lens for that person when their eyes are focused at
their near point?
a. 1.5
b. 2.5
c. 3.5
d. 4.5
16. A
compound microscope has an objective with a focal length of 5.00 mm and an
eyepiece of
focal length 4.00 cm. If the two
lenses are separated by 20.0 cm, what is the total magnification?
a. 12.5
b. 25.0
c. 125
d. 250
17. A
compound microscope has a 18-cm barrel and an objective with a focal length
of 8.0 mm.
What is the focal length of the eyepiece to give a total
magnification of 240?
a. 0.13
cm
b. 1.5 cm
c. 1.9 cm
d. 2.3 cm
Answers:
1. b
2. c
3. c
4. d
5. b
6. a
7. b
8. b
9. b
10. b
11. a
12. b
13. d
14. c
15. c
16. d
17. d