Description : An FDM hierarchy which is formed by frequency – division multiplexing 10 super groups together for a combined capacity of 600 voice band message channels.
Last Answer : Mastergroup
Description : A single fiber can handle as many voice channels as ∙ A. a pair of copper conductors ∙ B. a 1500-pair cable ∙ C. a 500-pair cable ∙ D. a 1000-pair cable
Last Answer : B. a 1500-pair cable
Description : An FDM hierarchy which is formed by frequency – division multiplexing five groups containing 12 channels each for a combined bandwidth of 240 kHz
Last Answer : Supergroup
Description : FDM telephone systems accommodate many channels by:
Last Answer : Using multiple levels of multiplexing
Description : The term single mode and multimode are best described as ∙ A. a number of fibers placed into fiber-optic cable ∙ B. the number of voice channels each fiber can support ∙ C. the number of wavelengths each fiber can support ∙ D. the index number
Last Answer : C. the number of wavelengths each fiber can support
Description : It is proposed network designed by major telephone companies in conjunction with the ITU-T with the intent of providing worldwide telecommunications support for voice, data, video and facsimile information within the same networ
Last Answer : ISDN
Description : In communication systems the frequency range used for voice is:
Last Answer : 300 Hz to 3800 Hz
Description : The most common method used for sampling voice signals in PCM systems.
Last Answer : flat top sampling
Description : It is caused by valence electrons in the silica material from which the fiber are manufactured.
Last Answer : ultraviolet absorption
Description : It is analogous to power dissipation to copper cables, impurities in the fiber absorb the light and covert it to heaT
Last Answer : absorption loss
Description : The maximum angle in which external light rays may strike the air/glass interface and still propagate down the fiber.
Last Answer : Acceptance cone half-angle
Description : What phenomenon will result if the glass fiber is exposed to long periods of high humidity?
Last Answer : stress corrosion
Description : Developed an optical fiber with losses less that 2 dB/km
Last Answer : Kao and Bockham
Description : A popular light wavelength fiber-optic cable is
Last Answer : 1.3 micrometer
Description : Which type of fiber-optic cable is the most widely used?
Last Answer : multimode step-index
Description : Which type of fiber-optic cable has the least modal dispersion?
Last Answer : single-mode step index
Description : These bends are caused by excessive pressure and tension and generally occur while fiber are bent during handling or installation.
Last Answer : constant-radius bending
Description : They were granted patents for scanning and transmitting television images through uncoated fiber cables
Last Answer : Baird and Hansel
Description : They proposed a new communication medium using cladded fiber cables.
Description : He coined the term “fiber optics” in 1956.
Last Answer : Kapany
Description : Approximately what is the frequency limit of the optical fiber?
Last Answer : 40 GHz
Description : _______ is a standard developed by ANSI for fiber-optic networks.
Last Answer : SONET
Description : The termssinglemode andmultimode are bestdescribes as a. the number of fibers placed into a fiber-optic cable b. the number of voice channels each fiber can support c.thenumber ofwavelengths eachfiber cansupport d. the index number
Last Answer : c.thenumber ofwavelengths eachfiber cansupport
Description : The term single mode and multimode are best described as:
Last Answer : the number of wavelengths each fiber can support
Description : Single-mode step-index cable has a core diameter in the range of
Last Answer : 2 to 15 micrometer
Description : What carrier system multiplexes 96 voice band channels into a single 6.312 Mbps data signal? A. T1 carrier system B. T2 carrier system C. T1C carrier system D. T3 carrier system
Last Answer : B. T2 carrier system
Description : The magnetic field of an antenna is perpendicular to the earth. The antenna’s polarization ___
Last Answer : is horizontal
Description : It is the ratio of the power density radiated in a particular direction to the power density radiated to the same point by a reference antenna, assuming both antennas are radiating the same amount of power
Last Answer : directive gain
Description : The property of interchangeability for the transmitting and receiving operations is known as ____
Last Answer : reciprocity
Description : The fields surrounding the antenna do not collapse their energy back into the antenna but rather radiate it out in space
Last Answer : radiation field
Description : It is the ratio of the radiated to the reflected energy:
Last Answer : Radiation efficiency
Description : It is the resistance that, if it replaced the antenna, would dissipate exactly the same amount of power that the antenna radiates
Last Answer : . Radiation resistance
Description : Plots of field strength or power density with respect to the value at a reference point.
Last Answer : relative radiation pattern
Description : The radiation pattern plotted in terms of electric field strength or power density
Last Answer : absolute radiation pattern
Description : The line bisecting the major lobe, or pointing from the center of the antenna in the direction of maximum radiation is called _____
Last Answer : line of shoot
Description : A special type of transmission line that consist of conducting metallic tube through which high frequency electromagnetic energy is propagated
Last Answer : waveguide
Description : If energy is applied at the geometrical center of antenna, the antenna is said to be ___
Last Answer : center-fed
Description : The radiation pattern of collinear and a broadside antenna is __
Last Answer : bidirectional
Description : Hertz antenna are predominantly used with frequencies above
Last Answer : 2MHz
Description : The point on the antenna where the transmission line is connected is called _____
Last Answer : feedpoint
Description : The discone antenna is
Last Answer : useful as a UHF receiving antenna
Description : It is the same with directive gain except that the total power fed to the antenna is used and the antenna efficiency is taken into account.
Last Answer : power gain
Description : ____ is a process-to-process protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer.
Last Answer : UDP
Description : ______ are special-interest groups that quickly test, evaluate, and standardize new technologies
Last Answer : Forums
Description : _______ refers to the structure or format of the data, meaning the order in which they are presented.
Last Answer : Semantics
Description : ________ defines how a particular pattern to be interpreted, and what action is to be taken based on that interpretation.
Last Answer : syntax
Description : The effect of a large magnitude of the numerical aperture.
Last Answer : The amount of external light the fiber will accept is greater
Description : It is the figure of merit used to measure the magnitude of the acceptance angle.
Last Answer : numerical aperture
Description : It is a result of photons of light that are absorbed by the atoms of the glass core molecule
Last Answer : infrared absorption
Description : Laser light is very bright because it is:
Last Answer : coherent