Jeff Rodgers
Ch 4 TEST Q/A
|
What
are pulses and why are they important in digital communication? (Choose two.) |
|
|
|
irregular
accidental spikes in energy levels |
|
|
determine
the value of the data being transmitted |
|
|
create
the timing mechanism for data transmission |
|
|
increases
in energy which damage data transmissions |
|
|
deliberate,
fixed disturbances of predictable duration |
|
Which
of the following describe sine waves? (Choose three.) |
|
|
|
They
do not continuously vary with time. |
|
|
They
repeat the same pattern at regular intervals. |
|
|
They
occur naturally and change regularly over time. |
|
|
They
are artificially created and do not occur naturally. |
|
|
No
two adjacent points on a graph have the same value. |
|
|
They
have continuously varying patterns that do not repeat. |
|
Which
of the following units of measure are commonly used in formulas for
calculating the amount of gain or loss in networking signals? (Choose three.) |
|
|
|
watts |
|
|
ohms |
|
|
volts |
|
|
decibels |
|
|
joules |
|
|
amperes |
|
Which
of the following are true about square waves? (Choose three.) |
|
|
|
They
repeat the same pattern at regular intervals. |
|
|
They
continuously vary with time. |
|
|
They
repeat the flat pattern on both the top and bottom of the wave. |
|
|
They
do not continuously vary with time. |
|
|
They
occur naturally and change regularly over time. |
|
|
They
change intervals based upon voltage. |
|
What
are some of the factors that contribute to attenuation in a copper media?
(Choose three.) |
|
|
|
type
of voltage used |
|
|
long
cable lengths |
|
|
jitter
signal sent by the transmitting device |
|
|
defective
connectors |
|
|
energy
leaks through the insulation of the cable |
|
|
low
signal frequencies |
|
What
is the purpose of shielding in copper based media? (Choose three.) |
|
|
|
protect
one pair of wires within the cable from noise generated by electrical signals
on another pair of wires |
|
|
ground
the cable and prevent electrical shocks |
|
|
protect
the data signal from external sources of noise |
|
|
eliminate
signal loss by keeping the transmitted signal confined to the cable |
|
|
decrease
attenuation and increase the length possible for the cable run |
|
|
ground
the cable so that the zero volt reference point is accurate |
|
Which
of the following is another name for the binary number system? |
|
|
|
Base
2 |
|
|
Base
5 |
|
|
Base
10 |
|
|
Base
16 |
|
For
which type of waves would the signal gain or loss be calculated using the
power formula? (Choose two.) |
|
|
|
electromagnetic
waves on copper cables |
|
|
electrical
waves on copper cables |
|
|
light
waves on optical fiber |
|
|
radio
waves in the air |
|
|
sound
waves in the air |
|
Identify
common ways in which the capacities of communication systems are measured?
(Choose two.) |
|
|
|
analog
bandwidth |
|
|
resistance
capacity |
|
|
carrier
bandwidth |
|
|
polarity
capacity |
|
|
digital
bandwidth |
|
Which
of the following are possible sources of line noise? (Choose three.) |
|
|
|
radio
transmitters |
|
|
electrical
motors |
|
|
crosstalk |
|
|
laser
light |
|
|
incandescent
light |
|
Why
would fiber optic installations be favored over copper between buildings?
(Choose two.) |
|
|
|
cheaper
installation |
|
|
larger
media |
|
|
attentuation
properties |
|
|
no
electrical interference |
|
|
easier
termination and installation |
|
What
type of shielding does data coaxial cable use? (Choose two.) |
|
|
|
insulating
material |
|
|
lexan
infused |
|
|
braided
conductive |
|
|
foil-screened |
|
|
rubber
molding |
|
What
problems are associated with impedance mismatches in copper cabling? (Choose
two.) |
|
|
|
jitter |
|
|
signal
absorption |
|
|
termination
of signals |
|
|
reflection |
|
|
NEXT |
|
What
conditions are described when transmission signals from one wire pair affects
another wire pair? (Choose two.) |
|
|
|
noise |
|
|
resistance
mismatch |
|
|
jitter |
|
|
crosstalk |
|
|
attenuation |
|
Which
of the following are tests specified by the TIA/EIA-568-B standard for copper
cable? (Choose three.) |
|
|
|
signal
harmonics |
|
|
conductive
response |
|
|
wire
map |
|
|
signal
absorption |
|
|
insertion
loss |
|
|
propagation
delay |
|
Which
features of fiber optic cabling prevent the problem of crosstalk? (Choose
two.) |
|
|
|
the
absence of electrical signals |
|
|
more
twists per inch than copper |
|
|
better
termination standards |
|
|
the
cancellation effect |
|
|
no
generation of electromagnetic waves |
|
What
type of wiring problem is depicted in this sample of a cable tester? |
|
|
|
a
fault |
|
|
a
short |
|
|
an
open |
|
|
a
split |
|
|
a
good map |
|
In
a new network installation, the network administrator has decided to use a
medium that is not affected by electrical noise. Which cable type will best
meet this standard? |
|
|
|
coaxial |
|
|
screened
twisted pair |
|
|
shielded
twisted pair |
|
|
unshielded
twisted pair |
|
|
fiber
optic |
|
How
does noise impact a data signal in a communication system? |
|
|
|
It
replaces the data signal. |
|
|
It
blocks the data signal. |
|
|
It
is added to the data signal. |
|
|
It
creates a harmonic signal. |
|
For
what purpose are two y-axis inputs used when displaying voltage patterns on
an oscilloscope? |
|
|
|
to
insure a clean signal is obtained |
|
|
to
determine if one is primary and one is backup |
|
|
to
display multiple time frames |
|
|
to
analyze a complex spectrum |
|
|
to
observe and measure two waves simultaneously |
|
What
type of analysis is performed by using an oscilloscope? |
|
|
|
power-domain |
|
|
frequency-domain |
|
|
time-domain |
|
|
wave-domain |
|
|
spectrum-domain |
|
|
signal-domain |
|
Which
of the following describes frequency? |
|
|
|
length
of each wave |
|
|
height
of each wave |
|
|
number
of cycles each second |
|
|
amount
of time between each wave |
|
How
are binary ones and zeros represented in fiber optic installations? (Choose
two.) |
|
|
|
+5
volts/-5 volts |
|
|
0
volts/5 volts |
|
|
light/no
light |
|
|
high
to low electrical transition |
|
|
low
to high electrical transition |
|
|
increasing/decreasing
light intensity |
|
Which
of the following correctly matches the definitions of analog and digital
bandwidth? (Choose two.) |
|
|
|
Analog
bandwidth refers to frequency range. |
|
|
Analog
bandwidth is a measurement of the amount of frequency sent. |
|
|
Digital
bandwidth refers to the range of a frequency. |
|
|
Digital
bandwidth measures speed of the transmission. |
|
|
Analog
bandwidth is a measurement of how much information can flow. |