Deck 3: Data Transmission

Question 1

Guided media,also called wireless,provide a physical means for guiding electromagnetic waves through seawater.

Answer 1

False

Question 2

The sine wave is the fundamental aperiodic signal.

Answer 2

False

Question 3

Delay distortion occurs because the velocity of propagation of a signal through a guided medium varies with frequency.

Answer 3

True

Question 4

For any given medium,the greater the bandwidth transmitted,the greater the cost.

Question 5

In ________ transmission signals are transmitted in only one direction; one station is the transmitter and the other is the receiver.

A)half duplex
B)simplex
C)full duplex
D)multipoint

Question 6

The greater the bandwidth of the signal the greater its information carrying capacity.

Question 7

A major problem in designing a communications facility is transmission impairment.

Question 8

A familiar example of analog data is audio,which,in the form of acoustic sound waves,can be perceived directly by human beings.

Question 9

Analog signals suffer more from attenuation than do digital signals.

Question 10

There is not a direct relationship between data rate and bandwidth.

Question 11

The term ________ is used to refer to the transmission path between two devices in which signals propagate directly from transmitter to receiver with no intermediate devices other than amplifiers or repeaters used to increase signal strength.

A)direct link
B)unguided media
C)wireless
D)guided

Question 12

The frequency is the rate at which the signal repeats.

Question 13

In full-duplex operation both stations may transmit,but only one at a time.

Question 14

A(n)________ signal is a continuously varying electromagnetic wave that may be propagated over a variety of media,depending on spectrum.Examples are wire media and fiber optic cable.

A)digital
B)periodic
C)aperiodic
D)analog

Question 15

The advantages of digital signaling are that it is generally cheaper than analog signaling and is less susceptible to noise interference.

Question 16

A guided transmission medium is ________ if it provides a direct link between two devices and those are the only two devices sharing the medium.

A)multipoint
B)simplex
C)point-to-point
D)wireless

Question 17

A digital signal is one in which the signal intensity maintains a constant level for some period of time and then abruptly changes to another constant level.

Question 18

Only digital signals can be used to convey information in the communications environment.

Question 19

An analog signal can be transmitted only a limited distance before attenuation,noise,and other impairments endanger the integrity of the data.

Question 20

A key parameter that characterizes any electromagnetic signal is ________,which is the width of the range of frequencies that comprises the signal.

A)analog
B)wavelength
C)bandwidth
D)digital

Question 21

The ________ of a signal is the distance occupied by a single cycle.

A)bandwidth
B)frequency
C)wavelength
D)amplitude

Question 22

In a ________ guided configuration more than two devices share the same medium.

Question 23

The ________ bandwidth is the band where most of the signal energy is concentrated.

Question 24

A technique known as ________ is used to provide a flicker free image without increasing the bandwidth requirement.

Question 25

________ is generated by terminals.computers,and other data processing equipment and then converted into digital voltage pulses for transmissions.

A)Voice
B)Audio
C)Binary data
D)Text

Question 26

An example of digital data is ________ or character strings.

A)interlaced
B)text
C)audio
D)video

Question 27

Thermal noise is also referred to as ________ noise.

Question 28

The designer of a communications facility must deal with four factors: the data rate that is used for digital information,the amount of noise and other impairments,the level of error rate that is acceptable and the ________ of the signal.

Question 29

When signals at different frequencies share the same transmission medium the result may be ________ noise.

A)crosstalk
B)white
C)intermodulation
D)impulse

Question 30

The communication of data by the propagation and processing of signals is ________.

A)interlacing
B)transmission
C)signaling
D)effective bandwidth

Question 31

A means of transmitting analog signals without regard to their content is ________ transmission.

Question 32

The rate in bits per second at which data can be communicated is the ________.

A)analog transmission
B)data rate
C)digital transmission
D)channel capacity

Question 33

The ________ is the maximum value or strength of the signal over time; typically this value is measured in volts.

A)period
B)phase
C)frequency
D)peak amplitude

Question 34

A(n)________ signal is a sequence of voltage pulses that may be transmitted over a wire medium.

A)audio
B)text
C)digital
D)analog

Question 35

To achieve greater distances in digital transmissions ________ are used.

Question 36

Twisted pair,coaxial cable and optical fiber are examples of ________ media.

Question 37

A reduction in strength is ________.

A)delay distortion
B)attenuation
C)pulsing
D)interlacing

Question 38

The ________ bandwidth of a signal is the width of the spectrum.

Question 39

The simplest sort of signal is a ________ signal,in which the same signal pattern repeats over time.

Question 40

The ________ of a signal is the range of frequencies that it contains.

A)spectrum
B)effective bandwidth
C)bandwidth
D)wavelength

Question 41

The ratio of the power in a signal to the power contained in the noise that is present at a particular point in the transmission is the ________ ratio.

Question 42

________ noise is noncontinuous,consisting of irregular pulses or noise spikes of short duration and of relatively high amplitude.It is generated from a variety of causes such as lightning and faults and flaws in the communications system.

Question 43

________ noise is due to thermal agitation of electrons.It is present in all electronic devices and transmission media and is a function of temperature.

Question 44

The maximum rate at which data can be transmitted over a given communication path under given conditions is referred to as the ________.

Question 45

Because of delay distortion some of the signal components of one bit position will spill over into other bit positions causing ________ interference,which is a major limitation to maximum bit rate over a transmission channel.