CCNA 1 v7 Modules 4 - 7: Ethernet Concepts Exam

What is the purpose of the OSI physical layer?

• exchanging frames between nodes over physical network media

• performing error detection on received frames

• transmitting bits across the local media

• controlling access to media

Why are two strands of fiber used for a single fiber optic connection?

• The two strands allow the data to travel for longer distances without degrading.

• They prevent crosstalk from causing interference on the connection.

• They allow for full-duplex connectivity.

• They increase the speed at which the data can travel.

Which characteristic describes crosstalk?

• the distortion of the network signal from fluorescent lighting

• the distortion of the transmitted messages from signals carried in adjacent wires

• the weakening of the network signal over long cable lengths

• the loss of wireless signal over excessive distance from the access point

Which procedure is used to reduce the effect of crosstalk in copper cables?

• twisting opposing circuit wire pairs together

• wrapping the bundle of wires with metallic shielding

• designing a cable infrastructure to avoid crosstalk interference

• requiring proper grounding connections

A network administrator is measuring the transfer of bits across the company backbone for a mission critical financial application. The administrator notices that the network throughput appears lower than the bandwidth expected. Which three factors could influence the differences in throughput? (Choose three.)

• the latency that is created by the number of network devices that the data is crossing

• the type of traffic that is crossing the network

• the sophistication of the encapsulation method applied to the data

• the amount of traffic that is currently crossing the network

What are two characteristics of fiber-optic cable? (Choose two.)

• It typically contains 4 pairs of fiber-optic wires.

• Each pair of cables is wrapped in metallic foil.

• It combines the technique of cancellation, shielding, and twisting to protect data.

• It is not affected by EMI or RFI.

• • It is more expensive than UTP cabling is.

What is a primary role of the Physical layer in transmitting data on the network?

• provide physical addressing to the devices

• determine the path packets take through the network

• control data access to the media

• create the signals that represent the bits in each frame on to the media

With the use of unshielded twisted-pair copper wire in a network, what causes crosstalk within the cable pairs?

• the magnetic field around the adjacent pairs of wire

• the reflection of the electrical wave back from the far end of the cable

• the use of braided wire to shield the adjacent wire pairs

• the collision caused by two nodes trying to use the media simultaneously

In addition to the cable length, what two factors could interfere with the communication carried over UTP cables? (Choose two.)

• • crosstalk

• • bandwidth

• • size of the network

  
  

• • signal modulation technique

  
  

• • electromagnetic interference

  
  

Which two devices commonly affect wireless networks? (Choose two.)

• external hard drives

• • Blu-ray players

• • home theaters

• • cordless phones

• • microwaves

• • incandescent light bulbs