Deck 15: Data Transmission

Question 1

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.
E)are used for both optics and digital signals.

Answer 1

B

Question 2

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

Answer 2

True

Question 3

The loudness of a signal is measured by its amplitude.

Answer 3

True

Question 4

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

Question 5

Analog signals differ from digital signals in that

A)analog signals are represented vs.time while digital signals are measured vs.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 a higher frequencies than digital signals.
E)digital signals operate at higher frequencies than analog signals.

Question 6

Attenuation is greater at lower frequencies.

Question 7

In general,noise can be defined as

A)loud,high amplitude signals.
B)errors in transmission.
C)signals generated by internetworking equipment.
D)analog signals instead of digital.
E)unwanted energy or signals on the transmission path.

Question 8

Given a frequency of 1000 Hz and a speed of 3X108 m/s (speed of light)what is the wavelength of the signal?

A)1000 m
B)3 m
C)3x108 m
D)3x105 m
E)3x103 m

Question 9

Convert 1 1/2 p radians to degrees.

A)45
B)90
C)180
D)270
E)360

Question 10

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 maximum amplitude of the signal.
E)the minimum amplitude in the signal.

Question 11

The frequency of human speech is in the range of

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

Question 12

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

Question 13

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)the difference between fiber and copper transmission properties.
E)line attenuation.

Question 14

Convert 45 to binary.

A)110101
B)101101
C)011111
D)100011
E)100 101

Question 15

The wavelength of an analog signal is

A)the distance traveled by the wave in the time defined by it's period.
B)the distance traveled by the wave in one second.
C)the distance traveled by the wave during its period.
D)the period of the wave.
E)the amplitude of the wave.

Question 16

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

Question 17

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.
E)the average of the lowest frequency used.

Question 18

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.
E)1 Hz.

Question 19

A sine wave is a periodic signal that

A)has equal phase,frequency and amplitude.
B)can be either digital or analog.
C)has a maximum peak amplitude equal to it's frequency.
D)has a frequency that is less than its amplitude.
E)can be measured in terms of it's amplitude,frequency and phase.

Question 20

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
E)4 Mbps

Question 21

Multipath problems are particularly problematic in line of sight applications.

Question 22

Atmospheric absorption occurs because of

A)the distances traversed in atmospheric transmission.
B)the water and oxygen content.
C)pollution and carbon content.
D)nitrogen content.
E)the ozone layer.

Question 23

Refraction refers to the bending of the signal.

Question 24

Because of it's characteristics,free space loss is a particular problems in

A)microwave tower transmissions.
B)wide area network transmissions.
C)dial up or modem transmissions.
D)satellite transmissions
E)LANs

Question 25

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