CCNA V3.1
Semestre 1 - Module 4

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1 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

2 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.

3 Identify common ways in which the capacities of communication systems are measured? (Choose two.)

analog bandwidth

resistance capacity

carrier bandwidth

polarity capacity

* digital bandwidth

4 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

5 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

6 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

7 What problems are associated with impedance mismatches in copper cabling? (Choose two.)

* jitter

signal absorption

termination of signals

* reflection

NEXT

8 What conditions are described when transmission signals from one wire pair affects another wire pair? (Choose two.)

* noise

resistance mismatch

jitter

* crosstalk

attenuation

9 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

10 What factors need to be considered to limit the amount of signal attenuation in long Ethernet cable runs? (Choose two.)

* type of media

number of users

type of users

* length of cable

type of electrical equipment

11 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

12 Which of the following describe amplitude?

* the height of each wave

the length of each wave

the number of waves each second

the amount of time between each wave

13 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

14 Which of the following are true concerning crosstalk? (Choose three.)

** FEXT is less of a problem than is NEXT.

Using frequency step sizes that are larger than those specified by the TIA/EIA standard has no effect on link fault detection.

** A cable with a NEXT measurement of 30 dB would be considered a better cable than one which has a NEXT measurement of 10 dB.

** NEXT needs to be measured from each pair to each other pair in a UTP link, and from both ends of the link.

FEXT is determined by injecting a signal into a pair of wires and measuring the signal strength on the other end of the same pair of wire.

15 Which frequencies are used by a cable tester to measure attenuation?

the lowest frequencies that the cable is rated to support

* the highest frequencies that the cable is rated to support

frequencies from 20 Hz to 20 kHz in 20 Hz increments

10 kHz and 100 GHz

16 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 represent digital signals.

* They do not continuously vary with time.

They occur naturally and change regularly over time.

They represent analog signals.

17 What is the purpose of shielding in copper based media? (Choose two.)

* protect the data signal from noise generated by electrical signal within the cable

ground the cable and prevent electrical shocks

* protect the data signal from external sources of noise

decrease attenuation and increase the length possible for the cable run

ground the cable so that the zero volt reference point is accurate

18 Why are pulses important in digital communication?

create the timing mechanism for data transmission

* determine the value of the data being transmitted

damage data transmissions

signal collisions in data streams

19 Two wires from different wire pairs are connected to the wrong pins on both ends of a cable. What is the wire fault name for this connection?

open

short

* split-pair

transposed-pair

20 Which of the following are detected by the wire map test? (Choose three.)

near-end crosstalk (NEXT)

* opens

propagation delay

return loss

* reversed-pair faults

* short circuits

21 Which one of the following cable tests verifies that all eight wires are connected to the correct pins on both ends of the cable?

cable length

insertion loss

near-end crosstalk (NEXT)

propagation delay

return loss

* wire map test

22 To ensure reliable LAN communications, what should a technician be looking for when attaching connectors to the ends of UTP cable?

that the white-orange/orange pair is attached first

* that the wire pairs remain twisted as much as possible

that one end of the shield is properly ground but not the other

that 50 ohm termination resistors are on both ends

23 What types of shielding are used in shielded twisted-pair (STP) cable? (Choose two.)

insulating material

lexan infused

* braided conductive

* foil-screened

rubber molding

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