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54 Cards in this Set

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