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 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 : 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 : Which type of fiber-optic cable has the least modal dispersion? ∙ A. single-mode step-index ∙ B. multimode step-index ∙ C. single-mode graded-index ∙ D. multimode graded-index
Last Answer : A. single-mode step-index
Description : Which type of fiber-optic cable has the least modal dispersion? ∙ a. Single mode step-index ∙ b. Multimode step-index ∙ c. Single-mode graded-index ∙ d. Multimode graded-index
Last Answer : ∙ a. Single mode step-index
Description : How can modal dispersion reduced entirely? ∙ A. Use a graded index fiber ∙ B. Use a single-mode fiber ∙ C. Use a monochromatic light source ∙ D. Use a very sensitive light detector
Last Answer : Use a single-mode fiber
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 : The effect of a large magnitude of the numerical aperture ∙ A. The amount of external light the fiber will accept is greater. ∙ B. The amount of external light the fiber will accept is less. ... The amount of modal dispersion will be less. ∙ D. The amount of chromatic dispersion will be greater.
Last Answer : The amount of external light the fiber will accept is greater.
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 : It indicates what signal frequencies can be propagated through a given distance of fiber cable. ∙ A. Bandwidth Distance Product ∙ B. Pulse width dispersion ∙ C. Rise time ∙ D. Cutoff frequency
Last Answer : A. Bandwidth Distance Product
Description : The upper pulse rate and information carrying capacity of a cable is limited by:
Last Answer : modal dispersion
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 : 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 : Modal dispersion is caused by the ∙ a. Dependence of wavelength on index of refraction ∙ b. Dependence of propagation constant on index of refraction ∙ c. Dependence of the propagation constant on the wavelength ∙ d. Dependence of the propagation constant on the mode number
Last Answer : d. Dependence of the propagation constant on the mode number
Description : What type of fiber has the highest modal dispersion? ∙ a. Step-index multimode ∙ b. Graded index multimode ∙ c. Step-index single mode ∙ d. Graded index mode
Last Answer : a. Step-index multimode
Description : A single-mode cable does not suffer from: a. modal dispersion b. chromatic dispersion c. waveguide dispersion d. all of the above
Last Answer : a. modal dispersion
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 : The bandwidth of a fiber is limited by ∙ a. Mode ∙ b. Wavelength ∙ c. Dispersion ∙ d. Frequency
Last Answer : c. 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 : 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 : 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 : Which of the cable length has the highest attenuation? ∙ a. 1 km ∙ b. 2 km ∙ c. 95 ft ∙ d. 5500 ft
Last Answer : ∙ b. 2 km
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 : 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 : 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 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 leakage current that flows through a photodiode with no light input ∙ A. dark voltage ∙ B. dark impedance ∙ C. dark power ∙ D. dark current
Last Answer : D. dark current
Description : 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
Last Answer : a. Thermally generated carriers in the diode
Description : The time it takes a light induced carrier travel across the depletion region of the semiconductor. ∙ A. dispersion ∙ B. response time ∙ C. irradiance ∙ D. transit time
Last Answer : D. transit time
Description : Chromatic dispersion can be eliminated by __________. ∙ A. using a monochromatic light source ∙ B. using a very small numerical aperture fiber ∙ C. using a graded-index fiber ∙ D. using a very sensitive photo detector
Last Answer : A. using a monochromatic light source
Description : The term dispersion describes the process of ∙ A. separating light into its component frequencies ∙ B. reflecting light from a smooth surface ∙ C. the process by which light is absorbed by an uneven rough surface ∙ D. light scattering
Last Answer : A. separating light into its component frequencies
Description : The ratio of the speed of light in a vacuum and the speed of light in the material used. ∙ a. S/N ratio ∙ b. Refractive index ∙ c. Intermodal dispersion ∙ d. Monomode ratio
Last Answer : b. Refractive index
Description : One of the following is not a characteristic of light detectors. ∙ a. Responsitivity ∙ b. Spectral response ∙ c. Transmit time ∙ d. Dispersion
Last Answer : ∙ d. Dispersion
Description : Dispersion is used to describe the ∙ a. Splitting of white light into its component colors ∙ b. Propagation of light in straight lines ∙ c. Bending of a beam of light when it goes from one medium to another ∙ d. Bending of a beam light when it strikes a mirror
Last Answer : a. Splitting of white light into its component colors
Description : Is the width of the range of wavelengths emitted by the light source ∙ a. Bandwidth ∙ b. Chromatic Dispersion ∙ c. Spectral width ∙ d. Beamwidth
Last Answer : c. Spectral width
Description : What is a specific path the light takes in an optical fiber corresponding to a certain angle and number of reflection ∙ a. Mode ∙ b. Grade ∙ c. Numerical Aperture ∙ d. Dispersion
Last Answer : a. Mode
Description : Which is the proper measurement of average power emitted by a pulsed laser? ∙ a. Energy x time ∙ b. Pulse energy x repetition rate ∙ c. Pulse energy / repetition rate ∙ d. Peak power x pulse length
Last Answer : ∙ b. Pulse energy x repetition rate
Description : The mechanical splice is best suited for ∙ A. quicker installation under ideal condition ∙ B. minimum attenuation losses ∙ C. field service conditions ∙ D. situations in which cost of equipment is not a factor
Last Answer : D. situations in which cost of equipment is not a factor
Description : When connector losses, splice losses and coupler losses are added, what is the limiting factor? ∙ A. source power ∙ B. fiber attenuation ∙ C. connector and splice loss ∙ D. detector sensitivity
Last Answer : D. detector sensitivity
Description : Fiber-optic cables with attenuation 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
Last Answer : C. 29.1 dB
Description : The mechanical splice attenuation loss is _____ dB or less ∙ a. 0.1 ∙ b. 0.01 ∙ c. 0.001 ∙ d. 1
Last Answer : a. 0.1
Description : Which is not a possible cause of optical fiber loss? ∙ a. Impurities ∙ b. Glass attenuation ∙ c. Stepped index operation ∙ d. Microbending
Last Answer : ∙ c. Stepped index operation
Description : Under normal condition, a single fiber should not be used for a two-way communication mainly because of ∙ a. Loss ∙ b. Fading ∙ c. Noise ∙ d. Attenuation
Last Answer : ∙ c. Noise
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 : Reflections in many directions ∙ a. Diffuse reflection ∙ b. Diffraction ∙ c. Scattering ∙ d. Dispersion
Last Answer : a. Diffuse reflection
Description : Material dispersion is caused by the ∙ a. Wavelength dependence of the index of refraction ∙ b. Wavelength independence of the index of refraction ∙ c. Dependence of the propagation constant on the mode number ∙ d. Independence of the propagation constant on the mode number
Last Answer : d. Independence of the propagation constant on the mode number