THEORETICAL OPTICS 1 Flashcards
1
Q
Which of the following is considered the smallest amount of light possible?
a. Photon c. Pencil
b. Ray d. Beam
A
A
2
Q
- You decide to install a solar collector on your roof to help heat your home. If you want to maximize the energy
absorption, which of the following colors should the collectors be?
a. White c. Blue
b. Green d. Black
A
D
3
Q
A pencil of light travels 2.5 meters from its source to a screen. The vergence of the pencil of light at the screen is;
a. 6.25 D c. 2.50 D
b. 5.00 D d. 0.40 D
A
D
4
Q
- Is the path of a single corpuscle of light.
a. Path c. Pencil
b. Ray d. Beam
A
B
5
Q
Luminous Intensity is;
a. A measure of the focusing power of the source
b. A number specifying the strength of the light falling on the surface.
c. A measure of the wavelength
d. The determination of the watts of light emitted from the source.
A
A
6
Q
- How many centimeters are there in a meter?
a. 0.01 c. 100
b. 10 d. 1000
A
C
7
Q
The basic metric unit in weight is;
a. Meter c. Gram
b. Centimeter d. Pound
A
C
8
Q
- In mathematic transformation,if a complete component is moved across the equal
sign to the other side of the equation;
a. The number is squared
b. The number will always become a negative number
c. The sign of the number is changed
d. The operation is possible but not as described in any of the answers above
A
C
9
Q
9.The opposite of – 4 is;
a. – ( - 4) b. Zero c. + 4
d. Both a & c are correct
A
D
10
Q
- Which of the following are not equal to 2(a+a) ?
a. 2a + 2a c ( 2+ 2) a
b. 2a squared d. 4a
A
B
11
Q
Which of the following is not a parallelogram?
a. Square c. Triangle
b. Rectangle d. Diamond
A
C
12
Q
- If a lens has a power of – 7.12 D. What is its focal length in centimeters?
a. + 13 cms c. + 14.04 cms
b. – 0.1404 m d. 5 in
A
C
13
Q
Light enters a lens in parallel rays produce a virtual image 0.50 meters in front of a lens. What is the power of a lens?
a. + 0.50 D c. – 2.00 D
b. – 0.50 D d. + 2.00 D
A
D
14
Q
- What is the height of the tower which cast a shadow 160 feet long when a
Vertical rod 3 feet high cast a shadow 4 feet long?
a. 112 ft b. 120 ft. c. 1200 ft.
d. 160 ft.
A
B
15
Q
According to this theory, light is propagated in the form of transverse wave.
a. Emission theory c. Photon theory
b. Undulatory theory d. Electromagnetic theory
A
B
16
Q
- The following are definition of Optics, except;
a. Study of light and vision
b. Study of nature and behavior of light
c. Study of how an electric current gives rise to magnetic field
d. Study of all phenomena related to light
A
C
17
Q
is the distance from one trough to the next trough.
a. Cycle c. Frequency
b. Amplitude d. Wavelength
A
D
18
Q
- Beam of light is the collection of divergent, convergent, or parallel pencils arising from an _______ source.
a. Point c. Incandescent
b. Extended d. Luminescent
A
B
19
Q
The nearer is the object from the pinhole camera, the _____ is the image.
a. Bigger c. Smaller
b. More distinct d. Less distinct
A
A
20
Q
- The shorter is the pinhole camera, the _____ is the image.
a. Less distinct c. More distinct
b. Smaller d. Bigger
A
B
21
Q
- An obstruction of the path of light from ______ will give rise to umbra AND PENUMBRA
a. An Extended Source c. A point source
b. A light source d. A white light
A
A
22
Q
The farther is the object from the pinhole camera, the _____ is the image.
a. More distinct c. Less distinct
b. Bigger d. Smaller
A
D
23
Q
- The following are true about luminous flux, except;
a. It is also known as luminous energy
b. Its unit is lumen
c. It is the rate of flow of light energy from a source
d. It is also known as luminous power
A
D
24
Q
This law states that the illumination of a surface increases the nearer it is from the source of light.
a. Cosine law of illumination c. Inverse Square Law
b. Law of intensity d. Soh – cah-toa law
A
C
25
25. Which is true about mean or average luminous intensity?
a. It is the amount of light emitted by the source in one given direction.
b. Its unit is lux or meter candle
c. It is the amount of light emitted by the source in all directions.
d. Its unit is steradian
A
26
The following are true about Illumination, except;
a. It is the amount of light received by a surface in a given position.
b. It is the amount of luminous flux spread over the area receiving the light
c. It is the flux per unit area
d. Its unit is lux, formerly called foot-candle
C
27
27. This law states that the illuminance of a surface varies as the cosine of the angle of incidence.
a. Law of intensity c. Reversibility principle
b. cosine law of illumination
B
28
It is also known as the brightness of the surface.
a. Illuminance c. Flux
b. Luminance d. Illumination
B
29
29. What is the illumination on the pavement at a point directly under a street lamp of
1500 candela hanging at a height of 25 feet?
a. 2.4 foot-candle c. 24-foot candle
b. 36 foot-candle d. 60-foot candle
A
30
. It is the rate of flow of light energy emitted by the source.
a. luminous intensity c. Luminous flux
b. illuminance d. Luminance
C
31
31. A pencil of light with positive vergence.
a. Convergent pencil c. Parallel pencil
b. Divergent pencil
A
32
photometer has a standard of 30 candle lamp at one end and a lamp of unknown intensity at the other end. The
two sides of the screen are equally illuminated when the screen is 3 feet from the standard lamp and 5 feet from the
unknown. What is the luminous intensity of the latter?
a. 53.33 candles b. 52.33 candles c. 83. 03 candles
d. 83.33 candles
D
33
33. What illuminance will be given on a desk by a 36candle fluorescent lamp 1 foot long placed 18 inches above the
surface? Solve in feet.
a. 24 ft. candles c. 4 ft. candles
b. 48 ft. candles
B
34
Multiple image formation occurs in plane mirrors dependent on the positioned angle. To get 8 images of a single
object, two plane mirrors should be positioned at an angle of;
a.30 degrees c. 60 degrees
b.40 degrees d. 180 degrees
B
35
35. A plane is used in exhibiting the laws of reflection in such a way that the normal ray, Incident ray and reflected ray
are shown. The concept of the term normal is understood as;
a. It is the imaginary line lying parallel to the reflecting surface.
b. It is imaginary line perpendicular to the incident ray at the point of contact with the mirror
c. It is imaginary line perpendicular to the reflected ray at the point of contact in the mirror
d. It is the imaginary line perpendicular to the medium’s surface at the point of incidence of the ray
D
36
An object 6 inches is placed 3 feet from a mirror. The image is formed on a screen 32 inches from the mirror. What
is the height of the image?
a.7.2 inches c. 5.3 inches
b.5.8 inches d.4.5inches
C
37
37. The characteristics of image will be dependent in different factors and the type of mirror. Which of the following type
of mirror a man will not see his image?
Greater than himself?
a. Convex c. Plane
b. Concave d. Parabolic
C
38
What is the angle of deviation on the case that a ray of light is incident towards a plane mirror at an angle of 30
degrees with the mirror surface?
a. 40 degrees c. 60 degrees
b.45 degrees d. 120 degrees
D
39
39. This type of image is formed by the intersection of the reflected rays and can be projected on the screen.
a. Real c. Diffuse
b. Virtual d. Perverted
A
40
When light is reflected off a mirror, it hits the mirror at the same angle as it reflects off the mirror, what kind of
phenomenon did occur?
a. Regular reflection c. Total Internal reflection
b. Diffuse reflection d. Interference
A
41
41. This type of image is formed by the intersection of the reflected rays themselves. Image formed in front of the
reflecting surface.
a. Real image c. Perverted image
b. Virtual image
A
42
It is the cardinal point in a spherical mirror that is the point in the center of the sphere from which the mirror was
sliced.
a. Principal focus c. Center of curvature
b. Vertex d. Radius of curvature
C
43
43. It is the distance from the mirror to the focal point, since the focal point is the midpoint between the vertex and the
center of curvature.
a. Radius of curvature c. Vertex
b. Focal length d. Principal focus
B
44
If the image is real and located in front of the mirror, the apparent distance would have a sign convention of;
a. Positive c. Minus
b. Negative d. Null
A
45
45. Upon computation of the size of the image it resulted to - 5 cms. As compared to 7 cms. object. What is the
characteristic of the image?
a. Inverted and minified c. Upright and minified
b. Inverted and magnified
B
46
An object is placed at the center of curvature in a concave mirror, the image will be located at;
a. Center of curvature c. Behind the center of curvature
b. Principal focus d. Between center of curvature & P.F.
a
47
47. A straight line through a center of curvature of a spherical reflecting surface and through the center of the sphere;
a. Principal axis c. Secondary line
b. Focal length d. Vertex
A
48
Visible light “is in the range of wavelength approximately between;
a.400 to 600 nm c. 380 to 760 nm
b.200 to 700 nm d. 200 to 380 nm
A
49
49. You decide to install solar collectors on your roof to help heat your home. If you want to maximize absorption, which
of the following colors should the collectors be?
a. White c. Blue
b. Green d. Black
D
50
Visible light going from high frequency to low frequency is;
a. Red, orange, yellow, blue, violet
b. Red, violet, blue, green, orange
c. Violet, blue, green, yellow, orange, red
d. Yellow, green, blue, violet, red, orange
C
51
51. Light travels outward in all directions from its source. The best explanation of this is that light takes the form of;
a. Radiated energy c. Wave fronts
b. Luminous waves
A
52
52.The distance between the crest of one wave and the crest of the next one is called?
a. Wave front c. Wavelength
b. Wave band d. Amplitude
C
53
53. It is equal to the solid angle of a cone, subtended at the center of the sphere, which cut off the area of the sphere’s
surface equal to the square of the radius;
a. Luminous flux c. Lumen
b. Illumination d. Steradian
D
54
The rate of flow of light energy from a source.
a. Luminous Intensity c. Luminous Power
b. Lumen d. Luminance
A
55
55. The amount of light emitted by the source in one given direction.
a. Luminous Intensity c. Luminous Power
b. Lumen
A
56
The amount of light received by a surface in a given position.
a. Luminous Flux c. Illumination
b. Luminous Intensity d. Brightness
C
57
57. The amount of light emitted per unit area of an illuminated surface.
a. Luminous Flux c. Illumination
b. Luminous Intensity d. Brightness
D
58
The brightness of a surface emitting a flux of one lumen per square feet;
a. Lambert c. Foot Lambert
b. Millilambert d. Candles
C
59
59. The illumination of the surface normal the direction of light, one foot from a source of one candle power is termed as;
a. Candles c. Foot Candle
C
60
The following laws governing geometrical optics, except;
d. Meter Candle
a. Law of Refraction c. Inverse Square Law
b. Law of Rectilinear
C
61
61. What is the type of the lens that has 1.25D on either side?
a. Pantoscopic Lens
b. Parascopic Lens
d. Law of Reflection
c. Periscopic Lens
d. None of the Above
C
62
What is the oldest lens; invented in the 8th century?
a. Nimrud
b. Crown Resin
c. Crown Glass
d. d. Zirconia
A
63
63. Abbe Value is named after –
a. Ernst Abbe
b. Constringence
c. Ernest Abbe
d. V Number
A
64
If you are required to produce a -7.00D lens with a back surface of +3.25D how much will be its front surface?
a. -10.25D c. -4.75D
b. -3.25D d. -9.50D
A
65
65. First glassmaking manual was owned by the Assyrian king named:
a. Ashurbanipal
b. Ashernizal
c. Azerbaijan
d. Ashernizapal
A
66
What is the theoretical point in the lens through which light passes unrefracted; point in a lens where prismatic effect
is zero?
a. Geometric Center c. Astigmatism
b. Optical Center d. Cylinder
B
67
67. What is the index of refraction of Ethyl Alcohol?
a. 1.34 c. 1.472
b. 1.454 d. 1.361
D
68
It is a theoretical point in the lens through which light passes unrefracted; a point in a lens where prismatic effect is
zero.
a. Geometrical Center c. Sphere
b. Optical Center d. Cylinder
B
69
69. Refraction takes place when parallel rays of light pass to one medium to another.
a. True
b. Maybe
c. False
d. I don’t know
A
70
What material has the highest index of refraction?
a. 18k Gold c. Plexiglass
b. Flint Glass d. Diamond
D
71
71. If you are required to produce a -3.75D lens with a back surface of +2.75D how much will be its front surface?
a. -6.50 D
b. -6.25 D
c. -5.75 D
d. -5.00 D
A
72
CR-39 is made up of:
a. Allyl Diglycol Polycarbonate
b. Columbia Resin
c. Allyl Diglycol Carbonate
d. None of the Above
C
73
73. It is used as an ophthalmic material that is made up of sand that is stricken by lightning.
a. Obsidian c. Tektite
b. Fulgurite
B
74
new ‘form’ of technique used for glass making.
a. Glass blowing c. Crown Glass
b. Glass blowers d. Flint Glass
A
75
75. It is an amorphous substance made primarily of silica fused at high temperatures with borates or phosphates:
a. Tektite c. Obsidian
b. Polycarbonate d. Glass
D
76
If you are required to produce a +5.00D lens with a back surface of +2.50D how much will be its front surface?
a. +3.00D c. +2.50D
b. -3.00D cm d. -2.50D
C
77
77. True or False: The higher the Abbe Value, the higher the Chromatic Aberration.
a. True c. Maybe
b. False
B
78
Latin word for ‘Lens’
a. Lenso c. Lumina
b. Lentima d. Lentil
D
79
79. Given a concave lens with a focal length of 15 inches what would be its total dioptre?
a. -2.66D c. -2.50D
b. -2.75D
B
80
It is the ratio of the weight of a substance to the weight of water with the same volume -
a. Index of refraction c. Specific Gravity
b. Focal Length d. Refraction
C
81
81. A person who requires a contact lens for a single prescription-for either myopia or hyperopia requires a _______ contact lens.
a. Toric
b. non-spherical
c. compound
d. spherical
D
82
A person with moderate to high degree of astigmatism must be fitted with a ____ contact lens when soft lens is the lens of
choice.
a. Toric
b. non-spherical
c. compound
d. spherical
A
83
83. With this lens type in recent years, there has been an increase in patient satisfaction as well as popularity due to an
improvement in ocular health.
a. disposable soft lenses
b. disposable RGP
c. conventional hydrogel lens
d. conventional PMMA lens
A
84
The ideal soft contact lens polymer should have the following characteristics:
a. O2 transmissibility
b. Biocompatibility
c. Wettability
d. all of the choices
e. biocompatibility and wettability only
D
85
85. The three methods used independently or combined to manufacturing soft contact lenses are lathing, molding and _______:
a. Centrifuge
b. oven casting
c. die casting
d. spin casting
D
86
Prescription is specified in quarter-diopter steps. The higher the number, the __________ there is.
a. more reflecting power
b. more bending power
c. less reflecting power
d. less bending power
B
87
87. Keratometry and corneal topography are two methods to measure;
a. peripheral topography
b. corneal curvature
c. corneal diameter
d. corneal water content
e. corneal power
B
88
When fitting a soft contact lens, examiner will perform a ______ test in order to determine lens centration:
a. push down
b. aperture size
c. blink rate
d. push up
e. push out
D
89
89. The base curve of a soft contact lens is typically ________ than the cornea.
a. Steeper
b. Smaller
c. Flatter
d. Larger
C
90
A tint which is used to hide corneal scar is called:
a. cosmetic tint
b. handling tint
c. opaque with clear pupil
d. cosmetic with opaque pupil
e. concentric tint
C
91
91. A patient wearing a SCL has a BOZR of 8.00 mm and a BVP of +8.00 DS. Push-up test revealed a high riding lens; this
means that the lens fit is:
a. Optimum
b. Flat
c. Steep
d. Loose
C
92
patient has a spectacle refraction of –9.00 D at a vertex distance of 14 mm. If we wanted to fit this patient with contact
lenses, what back vertex power (BVP) would be required for the CL?
a. –8.00 D
b. –8.75 D
c. –9.50 D
d. –10.00 D
A
93
patient is wearing a trial soft contact lens with the following parameters: BOZR = 7.75 mm OAD = 9.3 mm
BVP = –6.50DS; Evaluation of the lens on the eye shows that the lens is low riding, so you decide to order a new lens of the
same diameter but is 0.05 mm flatter. What should the base curve of this new lens be?
a. 7.90 mm
b. 7.80 mm
c. 7.70 mm
d. 7.85 mm
B
94
94. If toric contact is seen “off axis” or mislocated, this is measured in _____ relative to the vertical or horizontal directions.
a. Centimetres
b. Dioptres
c. Degrees
d. Millimetres
C
95
If a toric soft contact lens is seen to mislocate, what must be done to align the cylinder axis?
a. compensate for lens rotation
b. compensate for lens power
c. compensate for lens thickness
d. compensate for lens size
A
96
96. The patient’s ocular prescription is -2.00S/ -1.00C x60, and is mislocated by 20 degrees clockwise, compensate by giving:
a. -2.00DS/ -1.00DC x80
b. -2.00DS/ -1.00DC x40
c. -2.00DS/ -1.00DC x120
d. same Rx
A
97
Patient Y has been given the following Rx: -1.50 DS/ -1.25 DC x45, what must be the final cylinder axis if the contact lens
has mislocated 20 degrees counterclockwise?
a. x 25
b. x 35
c. x 65
d. x 20
A
98
98. The following Px wants to be fitted with contact lenses. He has never worn contact lenses and has no health or ocular
problems other than the refractive error. Findings are: Mean K readings: OU 44.00 @180; 44.50 @90 Refraction: OU -3.25 Dsph = -1.75 Dcyl x 180; Question: What is the amount of Corneal Astigmatism for this patient?
a. OU CA = -0.50D x180
b. OU CA = -0.75D x180
Manifest
c. OU CA = -0.50D x 90
d. OU CA = -0.25D x180
A
99
What base curve would be MOST suitable for a patient with a spectacle Rx of –5.25 D and keratometry measurements of
7.67 mm along 175° (44.00 D) and 7.99 mm along 85° (42.25 D)?
a. 7.8mm
b. 8.7mm
c. 7.9mm
d. 7.7mm
A
100
100. A 16-yr old boy is in your office and wants contact lenses. He has worn spectacles for the past 3 years. He is particularly
interested in contact lenses because he plays football and baseball. TBUT revealed 10 secs for OU. Findings are: Mean K
readings: OU 44.50 @180; 43.00 @90. MR: OU -3.25 Dsph = -1.50 Dcyl x 90
Question : What is the amount of Corneal Astigmatism for this patient?
a. OU -1.75D x 90
b. OU -1.25D x 90
c. OU -1.50D x 90
d. OU -1.50D x 95
C
