Which
network medium carries pulses of light?
A coaxial cable .
B. fibre optic cable .
C. UTP cable .
D. STP cable .
Which of
the following is an external source of degradation of the signal on cabling?
A EMI caused by electrical motors
B. RFI caused by light leakage
C. impedance caused by radio systems .
D. RFI caused by lighting
It repeats
the same pattern at regular intervals, no two adjacent points have the same
value, and it occurs naturally. This is
a description of:
A a square wave
B. a sine wave
C. a pulse
D a radio wave
It repeats
the same pattern at regular intervals, it does not vary continuously with time,
and the tops and bottoms of waves are flat.
This is a description of:
A a square wave
B. a sine wave
C. a pulse
D a radio wave
What is the
amplitude of a wave?
A The number of cycles per second
B The distance between peaks
C The height of the wave at its peak .
D The time taken between one peak passing
and the next
What is the
frequency of a wave?
A The number of cycles per second
B The distance between peaks
C The height of the wave at its peak .
D The time taken between one peak passing
and the next
What
instrument would be used to carry out time domain analysis of a wave?
A frequency analyzer
B multimeter
C cable tester
D oscilloscope
What is the
cause of crosstalk?
A cable wires that are too large in
diameter .
B too much noise in a cable’s data signal
.
C Electrical motors and lighting
D electrical signals from other wires in
a cable .
It is a
deliberate fixed disturbance of predictable duration that determines the value
of the data being transmitted. Which is
it?
A Spike
B sinewave
C pulse
D voltage
What is the unit for measuring the loss or gain of power in
a wave?
A volt
B decibel
C Watt
D ohm
Loss of power in a light wave is calculated using the
formula
10 log10(Pfinal /Pref). Pref
is the original power. In what units is
Pref measured?
A volt
B decibel
C watt
D ohm
The voltage formula 20log10(Vfinal/Vref)
is also used for measuring loss of power.
When would the voltage formula be used?
A for waves on
copper cable .
B for radio
waves .
C for waves in
fibre optic cables .
D for waves
traveling through the air .
Which of the following is true of impedance in networking
media?
A impedance
involves resistance to current that signal degradation causes .
B electrical
components in the network interface cards create impedance on the networking
media
C signal
degradation causes impedance .
D networking
media impedance needs to match the network interface card electrical components
Which of the following best describes attenuation?
A the
termination of a message .
B the
interception of a message .
C the weakening
of a message .
D the ignoring
of a message
Which of the following is not a factor that contributes to
attenuation in copper media?
A bad
connectors
B cable longer
than allowed by standards .
C low signal
frequencies
D energy
leaking out of the cable
What is an advantage of shielded twisted pair cable over
unshielded twisted pair cable?
A the cable is
easier to install .
B longer cables
can be used .
C signals are
protected from external noise .
D duplex
transmission can be used
What can be done to reduce the effects of crosstalk? (Choose two)
A use shielded
cable
B twist pairs
of same circuit wires together
C use thicker
installation round the cable .
D keep cables
away from sources of outside interference
How is data transmitted on a network using copper media?
A as
hexadecimal code
B as ASCII text
.
C as ones and
zeros
D as voltage
pulses
When can impedance degrade the signal in networking media?
A when
resistance opposes reactance
B when cable
impedance does not match network interface card electrical components .
C when the
networking media is not properly shielded from EMI/RFI interference .
D when
cancellation techniques are not employed
What is cancellation in networking media?
A the magnetic
fields of same circuit wires cancel each other .
B external
magnetic fields cancel the fields inside network cabling .
C wires in the
same circuit cancel each other’s electrical current flow .
D twisting wire
pairs cancels the electrical impedance in the wires .
Which of the following can be sources of external noise on
copper cabling? (Choose two)
A impedance
B EMI
C RFI
D OSI
Which of the following can cause problems with signals on
copper medium, but not on fibre optic cables?
(Choose three)
A power cables
.
B Electrical
motors
C attenuation
D radio
transmitters
E bad
connections .
What does digital bandwidth measure?
A the capacity
of a system for carrying signals .
B the time
taken for a signal to travel from one host to another .
C the diameter
of wires in a cable
D the number of
wires in the cable
Which type of cable uses a copper braid as shielding?
A STP cable .
B UTP cable .
C thin coaxial
cable .
D fibre optic
cable
What effect does noise have on a data signal?
A It removes
the signal from the cable .
B It is added
to the data signal and can make it unrecognisable .
C it sends a
jamming signal to all devices
D it replaces
the signal on the cable
What is NEXT?
A noise from an
electric motor that can be measured on a cable .
B noise that is
measured when a power cable shares a duct with the network cable
C noise from
other wires within the same cable when measured at the same end of the cable
D the total
delay of a signal caused by all the network devices .
What is a cause of jitter?
A impedance
mismatch, which causes signals to be reflected
B noise from
external sources .
C vibration
caused by working machinery
D signals being
sent too quickly by hosts
A new network is being planned. The administrator wants to use a medium that
will be cheap and easy to install. What
medium is likely to be chosen?
A fibre optic
cable .
B STP cable .
C UTP cable .
D thick coaxial
cable
A new network link is being planned. The cable must link buildings that are 600
metres apart, and it must pass through an area containing high voltage
electrical equipment. What medium is likely
to be chosen?
A fibre optic
cable .
B STP cable .
C UTP cable .
D thick coaxial
cable
What can be done to prevent crosstalk in fibre optic cables?
A increase the
thickness of the cladding layer
B make sure
that there are no kinks or sharp bends in the cable
C twist the
fibres round each other, so that the cancellation effect is used
D nothing needs
to be done as fibre optic cables do not suffer from crosstalk
Which of the following is not a test specified by the
TIA/EIA-568-B standard for copper cable?
A insertion
loss
B wire map .
C propagation
delay
D near end
crosstalk .
E twists per
inch .
F cable length
.
G delay skew
The term analogue bandwidth can be used to describe:
A rate of
transmission over a wireless link
B the range of
frequencies transmitted by a radio station or an electronic amplifier
C the speed of
a connection to the Internet using the phone line .
D the type of
signal modulation used by AM radio
How does electrical noise
affect networks?
A it shuts down
the network .
B it burns out
network devices, especially hubs .
C it reduces
data transmission speed through the network .
D it distorts
digital signals, so that they may become unrecognizable
What is a signal reference ground?
A the earthing
of the computer case, so that users do not receive shocks B a point that devices use to measure and
compare incoming digital signals to
C a device that
the name server users to send messages over the network .
D a device that
prevents sudden network failure when there is a power cut