Description : “When visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emitted”
Last Answer : Plank’s law
Description : When microwave energy is passed through a piece of ferrite in a magnetic field, another effect occurs. If the frequency of the microwave energy is much greater than the electron wobble frequency, the plane of polarization of the wavefront is rotated. This is known as
Last Answer : Faraday Rotation Effect
Description : The point on the antenna where the transmission line is connected is called _____
Last Answer : feedpoint
Description : Data rate at which serial PCM bits are clocked out of the PCM encoder onto the transmission line.
Last Answer : line speed
Description : They experimented with light transmission cables through bundle of fibers and lead to the development of flexible fiberscope
Last Answer : Van Heel, Hopkins and Kapany
Description : does its best to get a transmission through to its destination, but with no guarantees
Last Answer : best-effort delivery
Description : What circuit in the TV receiver is used to develop the high voltage needed to operate the picture tube?
Last Answer : Horizontal output
Description : At what frequency compared to the cutoff frequency of a waveguide will the wavefronts be reflected back and forth across the guide (setting up standing waves) and no energy
Last Answer : UHF receiving antenna
Description : The law that states “When visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emitted” is known as ____________. ∙ A. Einstein law of photon ∙ B. Marconi’s law ∙ C. Maxwell’s law ∙ D. Plank’s law
Last Answer : D. Plank’s law
Description : When electromagnetic wave are propagated through a waveguide, they A. are reflected from the walls but do not travel along them B. travel along all four walls of the waveguide C. travel along the broader walls of the guide D. travel through the dielectric without touching the walls
Last Answer : A. are reflected from the walls but do not travel along them
Description : A synchronous transmission usually begins with which character
Last Answer : SYN
Description : It involves converting standard logic levels to a form more suitable to telephone transmission lines
Last Answer : igital line encoding
Description : A synchronous transmission usually begins with which character?
Description : It is the transmission of information in any form from one source to one or more destination.
Last Answer : Multiplexing
Description : Synchronous transmission is used because:
Last Answer : no start and stop bits means higher efficiency
Description : The characters making up the message in a synchronous transmission are collectively referred to as the data
Last Answer : block
Description : A transmission of binary data which involves the transmission of two non – zero voltage level
Last Answer : Bipolar
Description : It is the ratio of the transmission bit rate to the minimum bandwidth required for a particular modulation scheme
Last Answer : Bandwidth efficiency, Information density, or Spectral efficiency
Description : For the 16-PSK and a transmission system with a 10kHz bandwidth, determine the maximum bit rate
Last Answer : 40,000 bps
Description : Rate of change of a signal on a transmission medium after encoding and modulation have occurred
Last Answer : baud rate
Description : Ethernet is baseband transmission system designed by _____
Last Answer : Robert Metcalfe and David Boggs
Description : __________ defines how a user gets control of the channel so as to allow transmission.
Last Answer : channel access
Description : Used for transmission of PCM encoded time – division multiplexed digital signal.
Last Answer : T carriers
Description : Category of data transmission if the binary pulse is maintained for the entire bit time?
Last Answer : Return to zero
Description : ______ are special-interest groups that quickly test, evaluate, and standardize new technologies
Last Answer : Forums
Description : In a waveguide, what is a frequency that would cause angles of incidence and reflection to be zero degrees?
Last Answer : Critical Frequency
Description : In changing the frequency of a cavity, what is accomplished by placing a nonmagnetic slug in the area of maximum H lines
Last Answer : Inductive Coupling
Description : The vertical field-scanning frequency is ______ Hz
Last Answer : 60
Description : In the Philippine color television system, the intercarrier frequency, in MHz, is
Last Answer : 4.5
Description : Which circuit is most common to both frequency-hopping and direct-sequence spread spectrum transmitters?
Last Answer : PSN code generator
Description : The result whenever the sampling rate is less than twice the highest audio frequency.
Last Answer : alias
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 : 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 : What is the frequency limit of a copper wire?
Last Answer : approximately 1.0 MHz
Description : In communication systems the frequency range used for voice is:
Last Answer : 300 Hz to 3800 Hz
Description : The best frequency demodulator is the:
Last Answer : PLL discriminato
Description : Approximately what is the frequency limit of the optical fiber?
Last Answer : 40 GHz
Description : Electromagnetic waves of frequencies arbitrarily lower than 3,000 GHz, propagated in space without artificial guide. A. Space waves B. Terrestrial waves C. Mobile D. Hertzian waves
Last Answer : D. Hertzian waves
Description : When electromagnetic waves are propagated in a waveguide a) They travel along the walls of the waveguide b) They travel through the dielectric without touching the walls c) They are reflected from the walls but do not travel along the walls d) None of these
Last Answer : When electromagnetic waves are propagated in a waveguide They travel through the dielectric without touching the walls
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 virtual circuit which is logically equivalent to a two-point dedicated private-line circuit except slower
Last Answer : Permanent Virtual Circuit
Description : Set rules implementing and governing an orderly exchange of data between layers of two devices, such as line control units and front – end processors.
Last Answer : Data Link Protocol
Description : It is logically equivalent to making telephone call through the DDD network except no direct end-to-end connection is made
Last Answer : Virtual call
Description : Packets which is self – contained and travels through the network independent of other packets of the same message by whatever means available
Last Answer : Datagram
Description : They were granted patents for scanning and transmitting television images through uncoated fiber cables
Last Answer : Baird and Hansel
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 : If energy is applied at the geometrical center of antenna, the antenna is said to be ___
Last Answer : center-fed
Description : The process of moving from one energy level to another is called __
Last Answer : Absorption