GRADED A+
◉ two ways we can use a flow of energy to carry data Answer: Analog
and digital
◉ Simplex Answer: A signal may flow in only one direction. A
commercial radio station uses simplex communication, because listeners
cannot transmit radio signals back to the station.
◉ Half-duplex Answer: Signals may flow in either direction, but not
simultaneously. For example, a two-way radio allows only one user to
speak at any one time.
◉ Full-duplex Answer: Signals may flow in both directions
simultaneously. A telephone is the best example of full-duplex
communication. One wire brings a signal from the telephone company to
your home, and a second wire carries a separate signal from your home
back to the telephone company. Thus, you can both hear and speak
simultaneously.
◉ Synchronous Answer: The communicating parties or endpoints use
time to organize communication. In a data network, two communicating
computers use each clock "tick" to detect whether a digital bit is a 1 or 0.
For example, as each time interval passes, a computer checks the
network cable to see whether the voltage is high (binary 1) or low
(binary 0). Because the timing determines the meaning of the signal, it is
,essential that the endpoints are synchronized to the same clock before
sending signals.
◉ Asynchronous Answer: Bits are not transmitted on any strict
timetable. For example, a computer modem typically uses 8 bits to
represent one character or letter. To indicate the start of each character,
the sending modem transmits a "start" bit to alert the receiving end to the
incoming signal. After the final bit of the eighth character is transmitted,
the sending modem transmits a "stop" bit to indicate the end of the
character. This process is repeated for each character the modem
transmits. Thus, the receiving modem must stay synchronized to the
signal only for the length of time it takes to transmit 8 bits. If the
sending and receiving clocks are slightly out of synchronization, these
short data transfers will still be successful.
◉ Which of the following is most typical of a broadband network?
Answer: Multiple analog channels
◉ Data bus size Answer: The size of the bus refers to the number of data
bits a CPU can work on in a single instruction.
◉ Clock speed Answer: The clock speed indicates how many
instructions per second the processor can execute. Each "tick" of the
clock is called a cycle, thus clock speed is measured in cycles per
second. A single cycle per second is called 1 hertz (Hz), 1,000 Hz is 1
kilohertz (kHz), 1 million Hz is 1 megahertz (MHz), and 1 billion Hz is
1 gigahertz (GHz). A CPU that runs at 400,000,000 cycles per second is
a 400- MHz processor.
, ◉ storage Answer: used to describe media that hold data for longer
periods, even when the power goes off.
◉ What components are common to all computer systems? (Check all
that apply.) Answer: Processor
Memory
Storage
I/O
◉ What does I/O stand for? Answer: Input / Output
◉ A NIC is a device used for: Answer: Signaling
◉ A sound card is what general type of computer component? Answer:
Input/output
◉ Distributed applications Answer: Applications can be distributed on
the network based on their requirements for resources. For example, an
application that provides computing-intensive services can be installed
on a computer with very high processing capacity, while the user's client
application runs on a workstation that provides high-end graphic display
capabilities.