CCNA1 v5 + v5.02 Chapter 4 Exam Answers
1. Which statement describes signaling at the physical layer?
- Signaling is a method of converting a stream of data into a predefined code
- Sending the signals asynchronously means that they are transmitted without a clock signal.
- In signaling, a 1 always represents voltage and a 0 always represents the absence of voltage.
- Wireless encoding includes sending a series of clicks to delimit the frames.
2. Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media?
- data link
3. A network administrator notices that some newly installed Ethernet cabling is carrying corrupt and distorted data signals. The new cabling was installed in the ceiling close to fluorescent lights and electrical equipment. Which two factors may interfere with the copper cabling and result in signal distortion and data corruption? (Choose two.)
- extended length of cabling
- signal attenuation
4. The throughput of a FastEthernet network is 80 Mb/s. The traffic overhead for establishing sessions, acknowledgments, and encapsulation is 15 Mb/s for the same time period. What is the goodput for this network?
- 15 Mb/s
- 55 Mb/s
- 65 Mb/s
- 80 Mb/s
- 95 Mb/s
5. What are two reasons for physical layer protocols to use frame encoding techniques? (Choose two.)
- to reduce the number of collisions on the media
- to provide better media error correction
- to increase the media throughput
- to distinguish data bits from control bits
- to identify where the frame starts and ends
6. How is the magnetic field cancellation effect enhanced in UTP cables?
- by increasing the thickness of the copper wires
- by increasing the thickness of the PVC sheath that encases all the wires
- by increasing and varying the number of twists in each wire pair
- by decreasing the number of wires that are used to carry data
7. What is one advantage of using fiber optic cabling rather than copper cabling?
- It is able to be installed around sharp bends.
- It is easier to terminate and install than copper cabling.
- It is usually cheaper than copper cabling.
- It is able to carry signals much farther than copper cabling.
8. Refer to the exhibit. The PC is connected to the console port of the switch. All the other connections are made through FastEthernet links. Which types of UTP cables can be used to connect the devices?
- 1 – rollover, 2 – crossover, 3 – straight-through
- 1 – rollover, 2 – straight-through, 3 – crossover
- 1 – crossover, 2 – straight-through, 3 – rollover
- 1 – crossover, 2 – rollover, 3 – straight-through
9. Which statement is correct about multimode fiber?
- SC-SC patch cords are used with multimode fiber cables.
- Multimode fiber commonly uses a laser as a light source.
- Multimode fiber has a thinner core than single-mode fiber.
- Multimode fiber cables carry signals from multiple connected sending devices.
10. Refer to the exhibit. What is wrong with the displayed termination?
- The cable is not shielded.
- The untwisted length of each wire is too long.
- The jack used is an RJ-11 connector instead of an RJ-45 connector.
- The wires are too thick for the connector that is used.
11. A network administrator is designing the layout of a new wireless network. Which three areas of concern should be accounted for when building a wireless network? (Choose three.)
- coverage area
- mobility options
- extensive cabling
- packet collision
12. 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 allow for full-duplex connectivity.
- They prevent crosstalk from causing interference on the connection.
- They increase the speed at which the data can travel.
13. A network administrator is required to upgrade wireless access to end users in a building. To provide data rates up to 1.3 Gb/s and still be backward compatible with older devices, which wireless standard should be implemented?
14. What is true concerning physical and logical topologies?
- The logical topology is always the same as the physical topology.
- Physical topologies display the IP addressing scheme of each network.
- Physical topologies are concerned with how a network transfers frames.
- Logical topologies determine the media access control method used.
15. What are two characteristics of 802.11 wireless networks? (Choose two.)
- Collisions can exist in the networks.
- They use CSMA/CA technology.
- They use CSMA/CD technology.
- Stations can transmit at any time.
- They are collision-free networks.
16. What is one main characteristic of the data link layer?
- It converts a stream of data bits into a predefined code.
- It shields the upper layer protocol from being aware of the physical medium to be used in the communication.
- It generates the electrical or optical signals that represent the 1 and 0 on the media.
- It accepts Layer 3 packets and decides the path by which to forward a frame to a host on a remote network.
17. As data travels on the media in a stream of 1s and 0s how does a receiving node identify the beginning and end of a frame??
- The transmitting node sends a beacon to notify that a data frame is attached.
- The receiving node identifies the beginning of a frame by seeing a physical address.
- The transmitting node sends an out-of-band signal to the receiver about the beginning of the frame.
- The transmitting node inserts start and stop bits into the frame.
18. What is the purpose of the FCS field in a frame?
- to compute the CRC header for the data field
- to verify the logical address of the sending node
- to obtain the MAC address of the sending node
- to determine if errors occurred in the transmission and reception
19. Fill in the blank.
What acronym is used to reference the data link sublayer that identifies the network layer protocol encapsulated in the frame? LLC
20. Fill in the blank with a number.
10,000,000,000 b/s can also be written as 10 Gb/s.
21. Fill in the blank.
The term bandwidth indicates the capacity of a medium to carry data and it is typically measured in kilobits per second (kb/s) or megabits per second (Mb/s).?