Description : It is analogous to power dissipation to copper cables, impurities in the fiber absorb the light and covert it to heat. ∙ A. power loss ∙ B. absorption loss ∙ C. resistive loss ∙ D. heat loss
Last Answer : B. absorption loss
Description : The loss in signal power as light travels down a fiber is called ∙ a. Dispersion ∙ b. Scattering ∙ c. Absorption ∙ d. Attenuation
Last Answer : ∙ d. Attenuation
Description : Which of the following is not a factor in cable light loss? ∙ A. reflection ∙ B. absorption ∙ C. scattering ∙ D. dispersion
Last Answer : A. reflection
Description : Which of the following is not a factor in cable light loss? ∙ a. Reflection ∙ b. Absorption ∙ c. Scattering ∙ d. Dispersion
Last Answer : ∙ a. Reflection
Description : For a single mode optical cable with 0.25 dB/km loss, determine the optical power 100 km from a 0.1-mW light source. ∙ A. -45 dBm ∙ B. -15 dBm ∙ C. -35 dBm
Last Answer : ∙ C. -35 dBm
Description : ________ 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
Last Answer : c. Infrared absorption
Description : The operation of a fiber-optic cable is based on the principle of ∙ A. refraction ∙ B. reflection ∙ C. dispersion ∙ D. absorption
Last Answer : A. refraction
Description : The operation of the fiber-optic cable is based on the principle of ∙ a. Refraction ∙ b. Reflection ∙ c. Dispersion ∙ d. Absorption
Last Answer : ∙ b. Reflection
Description : Band loss is ∙ a. A reduction in transmitter power caused by earth’s surface curvature ∙ b. A reduction in strength of the signal caused by folded dipole bends ∙ c. An attenuation increase caused by bends radiating from the side of the fiber ∙ d. All of these
Last Answer : c. An attenuation increase caused by bends radiating from the side of the fiber
Description : Light rays that are emitted simultaneously from an LED and propagated down an optical fiber do not arrive at the far end of the fiber at the same time results to ∙ A. intramodal dispersion ∙ B. pulse length dispersion ∙ C. modal dispersion ∙ D. wavelength dispersion
Last Answer : D. wavelength dispersion
Description : The term power budgeting refers to ∙ A. the cost of cable, connectors, equipment and installation ∙ B. the loss of power due to defective components ∙ C. the total power available minus the attenuation losses ∙ D. the comparative costs of fiber and copper installations
Last Answer : C. the total power available minus the attenuation losses
Description : The dominant loss mechanisms in silica fiber are ∙ a. Absorption and radiation losses ∙ b. Absorption and Rayleigh scattering ∙ c. Coupling and radiation losses ∙ d. Radiation and modal dispersion
Last Answer : b. Absorption and Rayleigh scattering
Description : Optical cable testers are used for ∙ a. Checking refractive index ∙ b. Light power out of a fiber ∙ c. Non-calibrated light into a fiber
Last Answer : b. Light power out of a fiber
Last Answer : ∙ b. Light power out of a fiber
Description : Cable attenuation is usually expressed in terms of ∙ A. loss per foot ∙ B. dB/km ∙ C. intensity per mile ∙ D. voltage drop per inch
Last Answer : . dB/km
Description : A fiber-optic cable has a loss of 15 dB/km. The attenuation in a cable 1000 ft. long is ∙ A. 4.57 dB ∙ B. 9.3 dB ∙ C. 24 dB ∙ D. 49.2 dB
Last Answer : A. 4.57 dB
Description : . 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
Last Answer : ∙ a. 4.57 dB
Description : Cable attenuation is usually expressed in terms of ∙ a. Loss per foot ∙ b. dB/km ∙ c. intensity per mile ∙ d. voltage drop per inch
Last Answer : ∙ b. dB/km
Description : It is caused by hydroxide ions in the material ∙ A. visible light absorption ∙ B. infrared absorption ∙ C. ultraviolet absorption ∙ D. ion resonance absorption
Last Answer : D. ion resonance absorption
Description : t is a result of photons of light that are absorbed by the atoms of the glass core molecule. ∙ A. ion resonance absorption ∙ B. infrared absorption ∙ C. ultraviolet absorption ∙ D. visible light absorption
Last Answer : B. infrared absorption
Description : It is caused by valence electrons in the silica material from which the fiber are manufactured. ∙ A. ion resonance absorption ∙ B. infrared absorption ∙ C. ultraviolet absorption ∙ D. visible light absorption
Last Answer : ultraviolet absorption
Description : The following are the cause of light attenuation in fiber optics except ∙ a. Backscattering ∙ b. Absorption ∙ c. Refraction ∙ d. Microbends
Last Answer : c. Refraction
Description : 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
Last Answer : D. modal dispersion
Description : A popular light wavelength fiber-optic cable is ∙ A. 0.7 micrometer ∙ B. 1.3 micrometer ∙ C. 1.5 micrometer ∙ D. 1.8 micrometer
Last Answer : B. 1.3 micrometer
Description : A popular light wavelength in fiber-optic cable is ∙ a. 0.7 um ∙ b. 1.3 um ∙ c. 1.5 um ∙ d. 1.8 um
Last Answer : b. 1.3 um
Description : 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
Last Answer : ∙ d. Modal dispersion
Description : The main benefit of light wave communications over microwaves or any other communications media are ∙ A. lower cost ∙ B. better security ∙ C. wider bandwidth ∙ D. freedom from interface
Last Answer : C. wider bandwidth
Description : Ratio of the velocity of propagation of a light ray in free space to the velocity of propagation of a light ray in free space in a given material. ∙ A. refractive index ∙ B. standing wave ratio ∙ C. velocity factor ∙ D. propagation velocity
Last Answer : ∙ A. refractive index
Description : Which of the following colors is not found in the visible light wave spectrum? ∙ a. Red ∙ b. White ∙ c. Orange ∙ d. Yellow
Last Answer : b. White
Description : Why are visible-light LEDs not used for fiber optics? ∙ a. It has high losses ∙ b. It has short wave ∙ c. It has low attenuation ∙ d. It has weak signal
Last Answer : ∙ a. It has high losses
Description : 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
Last Answer : c. Wider bandwidth
Description : Which theory states that the light wave behaves as if it consists of many tiny particles? ∙ a. Huygen’s theory ∙ b. Wave theory of light ∙ c. Nyquist theory ∙ d. Quantum theory
Last Answer : ∙ d. Quantum theory
Description : The process of moving from one energy level to another is called ____________. ∙ A. Spontaneous emission ∙ B. Excited emission ∙ C. Absorption ∙ D. Spontaneous decay
Last Answer : C. Absorption
Description : The process of decaying from one energy level to another energy level is called __________. ∙ A. Spontaneous emission ∙ B. Excited emission ∙ C. Absorption ∙ D. Any of these
Last Answer : A. Spontaneous emission
Description : Which of the following factor does not harm laser efficiency? ∙ a. Atmospheric absorption ∙ b. Excitation energy not absorbed ∙ c. Problems in depopulating the lower laser level ∙ d. Inefficiency in populating the upper laser level
Last Answer : ∙ a. Atmospheric absorption
Description : When light strikes a flat polished end of a fiber, the fiber loss produced can be reduced by ∙ a. Splicing ∙ b. Antireflection coating ∙ c. Insulation jacket ∙ d. All of these
Last Answer : ∙ b. Antireflection coating
Description : When light strikes a flat polished end of a fiber, it produces a loss of ∙ a. 14 % ∙ b. 4 % ∙ c. 10 % ∙ d. 1 %
Last Answer : ∙ b. 4 %
Description : It is caused by the difference in the propagation time of light rays that take different paths down the fiber. ∙ A. modal dispersion ∙ B. microbending ∙ C. Rayleigh scattering ∙ D. chromatic dispersion
Last Answer : A. modal dispersion
Description : More than one path for light rays to take down the fiber ∙ A. Multimode ∙ B. Step-index ∙ C. Single mode
Last Answer : A. Multimode
Description : Only one path for light rays to take down the fiber ∙ A. Multimode ∙ B. Step-index ∙ C. Single mode ∙ D. Graded index
Last Answer : C. Single mode
Description : The maximum angle in which external light rays may strike the air/glass interface and still propagate down the fiber. ∙ A. Acceptance cone half-angle ∙ B. Acceptance cone ∙ C. Critical angle ∙ D. Angle of incidence
Last Answer : A. Acceptance cone half-angle
Description : ______ dispersion is caused by the difference in the propagation times of light rays that take different paths down a fiber. ∙ a. Material dispersion ∙ b. Wavelength dispersion ∙ c. Modal dispersion
Last Answer : ∙ c. Modal dispersion
Description : Which type of fiber-optic cable is the most widely used? ∙ A. single-mode step-index ∙ B. multimode step-index ∙ C. single-mode graded index ∙ D. multimode graded index
Last Answer : B. multimode step-index
Description : Single-mode step-index cable has a core diameter in the range of ∙ A. 100 to 1000 micrometer ∙ B. 50 to 100 micrometer ∙ C. 2 to 15 micrometer ∙ D. 5 to 20 micrometer
Last Answer : . 2 to 15 micrometer
Description : Which of the following is not a major benefit of a fiber-optic cable? ∙ A. immunity from interference ∙ B. no electrical safety problems ∙ C. excellent data security ∙ D. lower cost
Last Answer : ∙ D. lower cost
Description : The core of fiber-optic cable is surrounded by ∙ A. wire braid shield ∙ B. Keviar ∙ C. cladding ∙ D. plastic insulation
Last Answer : ∙ C. cladding
Description : The core of a fiber-optic cable is made of ∙ A. air ∙ B. glass ∙ C. diamond ∙ D. quartz
Last Answer : B. glass
Description : Which cable length has the highest attenuation? ∙ A. 1 km ∙ B. 2 km ∙ C. 95 ft. ∙ D. 500 ft.
Last Answer : B. 2 km
Description : Which of the following is not a common type of fiber-optic cable? ∙ A. single-mode step-index ∙ B. multimode graded-index ∙ C. single-mode graded-index ∙ D. multimode step-index
Last Answer : . single-mode graded-index
Description : Which of the following is not a common application of fiber-optic cable? ∙ A. computer networks ∙ B. long-distance telephone system ∙ C. closed-circuit TV ∙ D. consumer TV
Last Answer : ∙ D. consumer TV