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 : The upper pulse rate and information carrying capacity of a cable is limited by:
Last Answer : 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 : ________ 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 d. Delay dispersion
Last Answer : c. 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 : 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 : Type of fiber that has the highest modal dispersion A. Step-index multimode B. Step-index single mode C. Graded index mode D. Graded index multimode
Last Answer : A. Step-index multimode
Description : An absorption loss caused by valence electrons in the silica material from which fibers are manufactured. A. Modal dispersion B. Infrared absorption C. Ion resonance absorption D. Ultraviolet absorption
Last Answer : D. Ultraviolet absorption
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 : 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 type of fiber-optic cable has the least modal dispersion?
Last Answer : single-mode step index
Description : Light travels faster in a material with a lower refractive index. Therefore, light rays that travel a longer distance in a lower refractive index travel at a greater average velocity. What effect does this have on multimode graded-index fiber modal dispersion and bandwidth?
Last Answer : Decreases the time difference between light rays, which reduces modal dispersion and increases fiber bandwidth.
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 : 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 : 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 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 : A cable carrying alternating current has (a) hysteresis losses only (b) hysteresis and leakage losses only (c) hysteresis, leakage and copper losses only (d) hysteresis, leakage, copper and friction losses
Last Answer : (b) hysteresis and leakage losses only
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 : Modal dispersion affects the bandwidth of multimode systems. It is essential to adjust what three fiber properties to maximize system bandwidth?
Last Answer : Core diameter, NA, and index profile properties.
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
Description : Loss due to the diffraction of light when it strikes on the irregularities formed during the manufacturing process of the fiber optics. A. Absorption loss B. Attenuation C. Bending loss D. Rayleigh scattering loss
Last Answer : D. Rayleigh scattering loss
Description : ECE Board Exam November 1996 The loss in signal power as light travels down a fiber is A. attenuation B. propagation C. absorption D. scattering
Last Answer : A. attenuation
Description : The antenna efficiency of an HF grounded vertical antenna can be made comparable to that of a half-wave antenna A. By installing a good ground radial system B. By isolating the coax shield from ground C. By shortening the vertical D. By lengthening the vertical
Last Answer : A. By installing a good ground radial system
Description : Shortening effect of an antenna that makes it appear as if it were 5% longer. A. End effect B. Flywheel effect C. Skin effect D. Capture effect
Last Answer : A. End effect
Description : How can the antenna efficiency of an HF grounded vertical antenna be made comparable to that of a half-wave antenna? A. By lengthening the vertical B. By installing a good ground radial system C. By shortening the vertical D. By isolating the coax shield from ground
Last Answer : B. By installing a good ground radial system
Description : ECE Board Exam March 1996 It is a spacecraft placed in orbit around the earth carrying onboard microwave receiver and transmitting equipments. A. Fiber optic equipment B. Communications satellite C. Wireless radio system D. Coaxial cable syste
Last Answer : B. Communications satellite
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 : Why are human population not limited by the carrying capacity of their ecosystem?
Last Answer : Humans are able to use their knowledge to locate resources they need.
Description : If the length of the fiber point defect changes with pulse duration, is the OTDR signal deviation a point defect or a region of high fiber attenuation?
Last Answer : A point defect.
Description : What is the free space attenuation of a satellite communications system operating at 36,000 km above the earth at 5.0 GHz? A. 198 dB B. 202 dB C. 142 dB D. 138 dB
Last Answer : A. 198 dB
Description : _________ is the random and unpredictable electric signals from natural causes, both internal and external to the system. A. Interference B. Attenuation C. Distortion D. Noise
Last Answer : D. Noise
Description : What is the required quality factor for an SSB filter with the following data: center frequency= 1 MHz, the desired attenuation level of the unwanted sideband= 80 dB and the separation between sidebands= 200 Hz? A. 1,250 B. 12,500 C. 125,000 D. 25,000
Last Answer : C. 125,000
Description : Atmospheric attenuation is an attenuation which is due to A. mist and fog B. gasses in the atmosphere C. water vapor and oxygen D. rain
Last Answer : C. water vapor and oxygen
Description : Which of the following phenomena is possible is free space medium? A. Reflection of radio wave B. Diffraction of radio wave C. Refraction of radio wave D. Attenuation of radio wave
Last Answer : D. Attenuation of radio wave
Description : The presence of standing waves on a transmission line is the result of A. a high level of attenuation on the line. B. terminating the line by a resistive load equal in value to the surge impedance ... input power to below its critical level. D. an impedance mismatch between the load and the line.
Last Answer : D. an impedance mismatch between the load and the line.
Description : What is the amount of sound reduction provided by a barrier – wall, floor, or ceiling called? A. Sound Attenuation B. Transmission loss C. Sound absorption D. Barrier loss
Last Answer : B. Transmission loss
Description : What is the current frequency band given most attenuation for satellite communications? A. Ku B. C band C. J D. P
Last Answer : A. Ku
Description : What is the path attenuation between transmitter and receiver at a frequency of 1.2 Ghz and a distance of 11,000 mi? A. 119 dB B. 115dB C. 179dB D. 174dB
Last Answer : C. 179dB
Description : What frequency does oxygen causes excessive attenuation A. 119 GHz B. 183 GHz C. 310 GHz D. 60 GHz
Last Answer : D. 60 GHz