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54 Cards in this Set
- Front
- Back
One disadvantage of microwave wavelengths is that the frequencies are susceptible to
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weather effects
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The term defined as the bending of radio waves or light waves as they travel at an angle from one medium to a second medium with a different density is
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refraction
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What is not a factor in determining the refractive index or air?
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propagaion medium
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The determining factor is calculating the correct size of a waveguide is
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frequency
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Which satellite communications system is used for monitoring space operations?
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DSCS
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High frequency transmissions follow what path from the antenna to the distant end?
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groundwave
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Which is not a disadvantage of laser light transmission?
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no need for carful alignment of transmitter and reciever
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Which landline transmission medium is the primary carrier of voice communications?
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twisted pair cable
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What are the two most popular types of coaxial cable used in network topologies?
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thicknet and thinnet
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What LAN communications technique does coaxial cable support?
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broadband, like a highway
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An optical communications system is compromised of a
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transmitter, cable, and receiver
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Why are fiber optic cables immune to EMI?
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fibers are made of dielectric material
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Materials made of air, glass, and water are
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transparent
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The direction change of a light beam caused by going form one transparent material into another is called
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refraction
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As the index of refraction value increases, the speed of light through that material
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decreases
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Which statement best describes a fiber optic cable's critical angle?
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the smallest angle of incidence between two media where total reflection takes place
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What term refers to a fiber optic cable's core with the same refractive index throughout the cable?
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step index
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Which type of fiber is the most effective at reducing wave dispersion?
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single mode, step index fiber
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What are the two principle weighting characteristics in use with telecommunication circuit noise?
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CCITT psophometric weighting and C-message weighting
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Which multiplexing method is used when digital signals are being transmitted?
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time division
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The two major types of frame structures are
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consultative CCITT and low speed
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The method of multiplexing the T1 multiplexer uses is
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time division
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What term is associated with the delay or lag introduced in the application of voltage from one section to the next?
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propagation constant
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What component of the microprocessor does all the computing?
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Arithmetic-logic unit
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What type of microprocessor has a large instructions set that contains complex instructions?
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CISC
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If you have a 33 MHz central processing unit, what math coprocessor is not compatible
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20 MHz coprocessor
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Main memory speed is measured in
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nanoseconds
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What type of ROM has the instructions to start the computer?
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basic I/O system
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Which one of the following is not contained in the first megabyte of memory?
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extended memory
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The distance between the head and the surface of the hard disk is known as
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flying height
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A 3.5-inch high-density magnetic disk has a storage capacity of up to
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1.44 megabytes
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A highly dense storage medium that looks like the audio disks found in music stores is called a
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CD-ROM
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Why should you never open a computer's power supply?
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the voltage inside power supplies can kill you
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The PC power supply is rated in
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watts
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Which one of the following is not one of the main areas on the keyboard?
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QWERTY keys
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The three keys one the keyboard that, when used with the function keys, provide more functions are the
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CTRL, ALT, SHIFT
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A printer contains a buffer storage to
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allow the central processing unit to perform other functions during printing
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What type of printer uses a special paper?
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thermal printer
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how does a thermal printer form a character
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dot matrix pattern
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A monitor's resolution is expressed in the number of pixels that make up the image -- so, the sharper the image, the
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higher the resolution
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How is an element of the plasma display darkened?
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the addressing circuit redices the sustaining voltage
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Which feature of the UNIX allows any users to work on he same computer system at the same time by sharing the computer's resources?
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multiuser
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Which of the following uses for the shell in UNIX is being invoked to create programs called shell scripts?
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prgramming
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Which of the following is not a UNIX shell?
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korne shell
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What improvement gave Windows 98 the ability to connect to 127 peripherals
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universal serial bus
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Windows NT is designed to be a(n)
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full-fledged NOS
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How much memory space (bytes_ does each buffer take up?
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512
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When the disk heads fly across the surface, in what order is data retrieved?
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the order in which it appearson the disk
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Name the access right that enables its user to act as a mini supervisor to grant rights to other users?
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access control
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What is the prime purpose of an operating system?
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improve system performance and ease of use
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The three main types of user interfaces
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command-drive, menu-driven, graphical
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In what manner does a DBMS store data?
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randomly
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The main difference between the flat-file and relational databases is
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relational databases model relationship in the real world
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The advantage of using firmware is
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faster operation and less susceptibility to unauthorized modifications
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