Deck 4: Data Transmission

Question 1

Impulse noise is the primary source of error in digital data communication.

Answer 1

True

Question 2

Attenuation is the reduction in signal strength as the signal propagates down the transmission path.

Answer 2

True

Question 3

In order to completely compensate for attenuation,the signal generated must be at least as high in strength than the noise of the channel.

Answer 3

False

Question 4

An antenna with a fixed area receives more signal power.

Question 5

Attenuation is greater at lower frequencies.

Question 6

The loudness of a signal is measured by its amplitude.

Question 7

A sine wave is a periodic signal that:

A)has equal phase,frequency and amplitude
B)can be measured in terms of its amplitude,frequency and phase
C)has a maximum peak amplitude equal to its frequency
D)can be either digital or analog

Question 8

Analog signals differ from digital signals in that:

A)analog signals are represented versus time while digital signals are measured versus frequency
B)analog signals are periodic,digital signals are not
C)analog signals are continuous while digital signals remain at one constant level and then move to another constant level
D)analog signals operate at higher frequencies than digital signals

Question 9

The wavelength of an analog signal is:

A)the distance traveled by the wave in the time defined by its period
B)the distance traveled by the wave in one second
C)the period of the wave
D)the amplitude of the wave

Question 10

Multipath problems are particularly problematic in line of sight applications.

Question 11

Digital signaling usually means that the information being conveyed is binary.

Question 12

Given a frequency of 60 Hz ( cycles per second ),the period of the signal is:

A)0.166667 sec.
B)0.166667 Hz.
C)one second
D)60 seconds

Question 13

Nearly all signals used for communications are part of the electromagnetic spectrum.

Question 14

Referring to Shannon's equation,in order to increase the data rate of a signal,we need only increase the bandwidth.

Question 15

For wireless facilities,there is a relatively free choice of where antennas are to be located.

Question 16

Typically,crosstalk does not have a debilitating effect on signal quality.

Question 17

Refraction refers to the bending of the signal.

Question 18

The various forms of noise include thermal noise,intermodulation noise,crosstalk,and impulse noise.

Question 19

Electromagnetic signals:

A)are used only for optics
B)are used for analog and digital signals
C)are used for digital signals only
D)are used for analog signals only

Question 20

In the telephone system,conversions are reproduced using the range from 300 - 3400 Hz in order to limit the required capacity of transmission lines.

Question 21

In general,noise can be defined as:

A)loud,high amplitude signals
B)errors in transmission
C)unwanted energy or signals on the transmission path
D)analog signals instead of digital

Question 22

________ is a measure of the position of the waveform relative to a given moment of time within the period of a signal.

Question 23

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

Question 24

The frequency of human speech is in the range of:

A)20 - 1000 Hz.
B)20 - 3400
C)300 - 3400 Hz.
D)10 - 25,000 Hz.

Question 25

The spectrum of a signal is:

A)the lowest frequency value subtracted from the highest
B)the range of frequencies in the signal
C)all of the frequencies from 0 to the highest frequency used
D)the average of the highest frequency and the lowest

Question 26

A(n)_________ signal is one in which the signal intensity maintains a constant level for some period of time and then changes to another constant level.

Question 27

Given a resolution of 320 pixels x 240 pixels,1 byte of color information per pixel and a transmission rate of 30 frames per second,calculate the bandwidth necessary for this signal:

A)18.4 Mbps
B)2.3 Mbps
C)18.4 Kbps
D)6 Mbps

Question 28

A(n)_________ signal is one in which the signal intensity varies in a smooth fashion over time.

Question 29

The _________ of a signal is defined as the distance between two points of corresponding phase of two consecutive cycles,such as maximum amplitudes or where the wave crosses zero.

Question 30

Signals produced on a line that is the sum or difference of the signals that created it is:

A)thermal noise
B)intermodulation noise
C)crosstalk
D)impulse noise

Question 31

Atmospheric absorption occurs because of:

A)the distance traversed in atmospheric transmission
B)the water and oxygen content
C)pollution and carbon content
D)nitrogen content

Question 32

The _________ is the number of times the signal makes a complete cycle within a given time frame.

Question 33

The __________ is the maximum height of the wave above or below a given reference point.

Question 34

The simplest sort of signal is a(n)_________ signal,in which the same signal pattern repeats over time.

Question 35

The bandwidth of a signal is:

A)the width of the spectrum
B)the average of the frequencies
C)the range of frequencies in the signal
D)the minimum amplitude of the signal

Question 36

For guided media such as twisted pair,coaxial cable,and optical fiber,the most significant sources of signal quality impairments are: attenuation and attenuation distortion,delay distortion,and __________.

Question 37

_________ is the unwanted coupling between signal paths.

A)Thermal noise
B)Intermodulation noise
C)Crosstalk
D)Impulse noise

Question 38

Data can exist in either analog or _________ form.

Question 39

Delay distortion is due to:

A)wait times between keyboard entry and actual transmission of data
B)portions of the signal arriving at the destination at different times
C)varying levels of signal strength
D)signals generated by internetworking equipment

Question 40

Because of its characteristics,free space loss is a particular problem in:

A)microwave tower transmissions
B)WANS
C)dial up or modem transmissions
D)satellite transmissions

Question 41

The four categories of noise are: thermal noise,intermodulation,impulse noise,and __________.

Question 42

__________ has been experienced by anyone who,while having a telephone conversation,has been able to hear another telephone conversation.

Question 43

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

Question 44

The rate at which data can be transmitted over a given communication path,or channel,under given conditions,is referred to as the ___________.

Question 45

The width of the range of frequencies that comprise the signal is the ________.