CCNA module 4

Question 1

is energy traveling from one place to
another

Answer 1

A wave

Question 2

• Discret, not continuous
• Can only have one or two voltage states
• Voltage jumps between 2 levels
• Made up of particular sine waves

Answer 2

Digital signals

Question 3

• Continuous voltage
• Voltage varies as time progresses
• Typical of things in nature
• Many encodings possible

Answer 3

Analog signals

Question 4

is a measurement unit important in
describing networking signals.

Answer 4

The decibel (dB)

Question 5

measures the loss or gain of the power of a wave.

Answer 5

dB

Question 6

Analyzing signals using an oscilloscope is
called

Answer 6

time-domain analysis

Question 7

which is noise from
other signals being transmitted
nearby

Answer 7

Radio frequency interference
(RFI),

Question 8

which is noise from
nearby sources such as
motors and lights

Answer 8

Electromagnetic interference
(EMI),

Question 9

noise at the transmitter
or receiver of an optical signal

Answer 9

Laser

Question 10

is an extremely important concept in
communications systems.

Answer 10

Bandwidth

Question 11

, data signals are represented by
voltage levels that represent binary ones and zeros.

Answer 11

On copper cable

Question 12

is used to transmit data signals by
increasing and decreasing the intensity of light to
represent binary ones and zeros.

Answer 12

Fiber optic cable

Question 13

in order for the LAN to operate properly, the receiving
device must be able to accurately interpret the binary
ones and zeros transmitted as

Answer 13

signal levels.

Question 14

is the decrease in signal amplitude over the length of a
link.

Answer 14

Attenuation

Question 15

contribute to greater signal
attenuation.

Answer 15

Long cable lengths and high signal frequencies

Question 16

Signal energy is also lost when it leaks through the ———– of the cable
and by impedance caused by defective connectors.

Answer 16

insulation

Question 17

• If a connector is improperly installed on Cat5, it will have
  a different impedance value than the cable.

Answer 17

Impedance Discontinuity

Question 18

cause attenuation and jitter as a
portion of signal will be reflected back to the
transmitting device.

Answer 18

Impedance mismatch

Question 19

the combination of the effects of signal attenuation and
impedance discontinuities is called

Answer 19

insertion loss.

Question 20

(NEXT)

Answer 20

Near-end Crosstalk

Question 21

(FEXT)

Answer 21

Far-end Crosstalk

Question 22

(PSNEXT)

Answer 22

Power Sum Near-end
Crosstalk

Question 23

are subject to the optical equivalent
of UTP impedance discontinuities.

Answer 23

Fiber links