You dont have javascript enabled! Please enable it! MCQ in Fiber Optics Communications Part 2 | ECE Board Exam

# MCQ in Fiber Optics Communications Part 2 | ECE Board Exam

This is the Multiples Choice Questions Part 2 of the Series in Fiber Optics Communications as one of the Communications Engineering topics. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize yourself with each and every question compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic Systems and Technologies, Communications Books, Journals, and other Communications References.

#### MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQ in Principles of Light Transmission
• MCQ in Types of Light Sources, Laser, LED
• MCQ in Light Detectors
• MCQ in Modulation and Waveform
• MCQ in System Design
• MCQ in General application
• MCQ in System Bandwidth
• MCQ in Splicing Techniques

#### Continue Practice Exam Test Questions Part 2 of the Series

Choose the letter of the best answer in each questions.

51. Which of the following is not a common application of fiber-optic cable?

a. Computer networks

b. Long-distance telephone systems

c. Closed circuit TV

d. Consumer TV

Explanation:

52. Total internal reflection takes place if the light ray strikes the interface at an angle with what relationship to the critical angle?

a. Less than

b. Greater than

c. Equal to

d. Zero

Explanation:

53. The operation of the fiber-optic cable is based on the principle of

a. Refraction

b. Reflection

c. Dispersion

d. Absorption

Explanation:

54. Which of the following is not a common type of fiber-optic cable?

a. Single-mode step-index

d. Multimode step-index

Explanation:

55. Cable attenuation is usually expressed in terms of

a. Loss per foot

b. dB/km

c. intensity per mile

d. voltage drop per inch

Explanation:

56. Which of the cable length has the highest attenuation?

a. 1 km

b. 2 km

c. 95 ft

d. 5500 ft

Explanation:

57. The upper pulse rate and information carrying capacity of a cable is limited by

a. Pulse shortening

b. Attenuation

c. Light leakage

d. Modal dispersion

Explanation:

58. The core of a fiber optic cable is made of

a. Air

b. Glass

c. Diamond

d. Quartz

Explanation:

59. The core of a fiber optic is surrounded by

a. Wire braid shield

b. Kevlar

d. Plastic insulation

Explanation:

60. The speed of light in plastic compared to the speed of light in air is

a. Slower

b. Faster

c. The same

d. Either lower or faster

Explanation:

61. Which of the following is not a major benefit of fiber-optic cable?

a. Immunity from interference

b. No electrical safety problems

c. Excellent data security

d. Lower cost

Explanation:

62. The main benefit of light-wave communications over microwaves or any other communications media is

a. Lower cost

b. Better security

c. Wider bandwidth

d. Freedom from interference

Explanation:

63. Which of the following is not part of the optical spectrum?

a. Infrared

b. Ultraviolet

c. Visible color

d. X-rays

Explanation:

64. The wavelength of visible light extends from

a. 0.8 to 1.0 nm

b. 400 to 750 nm

c. 200 to 660 nm

d. 700 to 1200 nm

Explanation:

65. The speed of light is

a. 186,000 mi/h

b. 300 mi/h

c. 300,000 m/s

d. 300,000,000 m/s

Explanation:

66. Refraction is the

a. Bending of light waves

b. Reflection of light waves

c. Distortion of light waves

d. Diffusion of light waves

Explanation:

67. The ratio of speed of light in air to the speed of light in another substance is called the

a. Speed factor

b. Index of reflection

c. Index of refraction

d. Dielectric constant

Explanation:

68. A popular light wavelength in fiber-optic cable is

a. 0.7 ยตm

b. 1.3 ยตm

c. 1.5 ยตm

d. 1.8 ยตm

Explanation:

69. Which type of fiber optic cable is most widely used?

a. Single-mode step-index

b. Multimode step-index

Explanation:

70. Which type of fiber-optic cable is the best for very high speed data?

a. Single-mode step-index

b. Multimode step-index

Explanation:

71. Which type of fiber-optic cable has the least modal dispersion?

a. Single mode step-index

b. Multimode step-index

Explanation:

72. Which of the following is not a factor in cable light loss?

a. Reflection

b. Absorption

c. Scattering

d. Dispersion

Explanation:

73. A distance of 8 km is the same as

a. 2.5 mi

b. 5 mi

c. 8 mi

d. 12.9 mi

Explanation:

74. A fiber-optic cable has a loss of 15 dB/km. The attenuation in a cable, 100 ft long is

a. 4.57 dB

b. 9.3 dB

c. 24 dB

d. 49.2 dB

Explanation:

75. Fiber-optic cables with attenuations of 1.8, 3.4, 5.9, and 18 dB are linked together. The total loss is

a. 7.5 dB

b. 19.8 dB

c. 29.1 dB

d. 650 dB

Explanation:

76. Which light emitter is preferred for high speed data in a fiber-optic system

a. Incandescent

b. LED

c. Neon

d. Laser

Explanation:

77. Most fiber-optic light sources emit light in which spectrum?

a. Visible

b. Infrared

c. Ultraviolet

d. X-ray

Explanation:

78. Both LEDs and ILDs operate correctly with

a. Forward bias

b. Reverse bias

c. Neither A or B

d. Either A or B

Explanation:

79. Single-frequency light is called

a. Pure

b. Intense

c. Coherent

d. Monochromatic

Explanation:

80. Laser light is very bright because it is

a. Pure

b. White

c. Coherent

d. Monochromatic

Explanation:

81. Which of the following is NOT a common light detector

a. PIN photodiode

b. Photovoltaic diode

c. Photodiode

d. Avalanche photodiode

Explanation:

82. Which of the following is the fastest light sensor

a. PIN photodiode

b. Photovoltaic diode

c. Phototransistor

d. Avalanche photodiode

Explanation:

83. Photodiodes operate property with

a. Forward bias

b. Reverse bias

c. Neither A or B

d. Either A or B

Explanation:

84. The product of the bit rate and distance of a fiber-optic system is 2 Gbits km/s. What is the maximum rate at 5 km?

a. 100 Mbits/s

b. 200 Mbits/s

c. 400 Mbits/s

d. 1000 Gbits/s

Explanation:

85. Which fiber-optic system is better?

a. 3 repeaters

b. 8 repeaters

c. 11 repeaters

d. 20 repeaters

Explanation:

86. An important requirement for successful transmission system using light

a. Powerful, reliable light source

b. Strong glass

c. Reliable, high cost transmission medium

d. Powerful regenerators

Explanation:

87. What is used to block light from a laser and let other light through

a. Neutral density

b. Color

c. Interference

d. Spatial

Explanation:

88. ________ is a light that can be coherent

a. Spontaneous emission

b. Monochromatic and in-phase

c. Narrow beam divergence

d. Monochromatic

Explanation:

89. Coherence of laser light is important for _________

a. Light propagation

b. Getting laser light to pass through air

c. Drilling holes

d. Holography

Explanation:

90. The ultrapure glass used to manufacture optical fibers is approximately ____ pure

a. 99.9 %

b. 99.99 %

c. 99.999 %

d. 99.9999 %

Explanation:

91. In fiber optics, PCS stands for

c. Personal carrier system

d. Personal communication

Explanation:

92. How many longitudinal modes can fall within a laserโs gain bandwidth?

a. 2

b. 5

c. 9

d. No fixed limit, dependent on bandwidth and mode spacing

Explanation:

93. _________ is the result of photons of light that are absorbed by the atoms of the glass core molecules

a. Ion resonance absorption

b. Ultraviolet absorption

c. Infrared absorption

d. Absorption loss

Explanation:

94. In fiber optics, SCS stands for

b. Silicon base-class-silica

Explanation:

95. Human laser was developed by A. Javen at Bell laboratory in

a. 1960

b. 1962

c. 1963

d. 1964

Explanation:

96. What parameter of light detector determines the range or system length that can be achieved for a given wavelength?

a. Transit time

b. Spectral response

c. Dark current

d. Responsitivity

Explanation:

97. Dark current in light detectors is caused by

a. Thermally generated carriers in the diode

b. The absence of light input

c. Small leakage current

d. Its imperfection

Explanation:

98. What is the unit of responsitivity?

a. Ampere/volt

b. Ampere/watt

c. Watt/ampere

d. Volts/ampere

Explanation:

99. One of the following is not a characteristic of light detectors.

a. Responsitivity

b. Spectral response

c. Transmit time

d. Dispersion

Explanation:

100. What is the typical wavelength of light emitted from epitaxially grown LEDs?

a. 840 nm

b. 490 nm

c. 480 nm

d. 940 nm

Explanation:

### Complete List of MCQ in Communications Engineering per topic

P inoyBIX educates thousands of reviewers and students a day in preparation for their board examinations. Also provides professionals with materials for their lectures and practice exams. Help me go forward with the same spirit.

โWill you subscribe today via YOUTUBE?โ

Subscribe

• Full Content Access Exclusive to Premium members

## PINOYBIX FREEBIES FOR PREMIUM MEMBERSHIP:

• CIVIL ENGINEERING REVIEWER
• CIVIL SERVICE EXAM REVIEWER
• CRIMINOLOGY REVIEWER
• ELECTRONICS ENGINEERING REVIEWER (ECE/ECT)
• ELECTRICAL ENGINEERING & RME REVIEWER
• FIRE OFFICER EXAMINATION REVIEWER
• LET REVIEWER
• MASTER PLUMBER REVIEWER
• MECHANICAL ENGINEERING REVIEWER
• NAPOLCOM REVIEWER

## FOR A LIMITED TIME

If you subscribe for PREMIUM today!