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ITT Tech Tucson NT 1210 Chapter 4 1)You have created a simple electrical circuit with a battery, wires, and a light bulb

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ITT Tech Tucson

NT 1210

Chapter 4

1)You have created a simple electrical circuit with a battery, wires, and a light bulb. Which of the following is true about this circuit? (Choose two answers.) a. The battery’s positive lead pushes current away from that lead.   b. The battery’s positive lead pulls current toward that lead. c. The circuit creates a direct current. d. The circuit creates an alternating current.

Answer: B, C. The current, which is the flow of energy from electrons, is negative. As a result, the negative lead on the battery repels the current, pushing the current away from the negative lead. The positive lead attracts the current, pulling the current toward the positive lead. Batteries typically keep the polarity (positive and negative leads) the same, never changing, so the current always flows in one direction, creating a DC circuit.

2.            A PC NIC and a switch port create one electrical circuit to use when sending data. The sender creates a (maximum) 1-volt electrical signal with a frequency of 1000 hertz. Which of the following facts are also true? (Choose two answers.)   a. The period is 1/1000 of a second.   b. The phase changes over time. c. The amplitude changes over time. d. The amplitude is 1 volt.

 

 

3.            A PC NIC and a switch port create one electrical circuit to use when sending data from the PC to the switch. Which of the following tasks is a function done by the transmitter? (Choose two answers.) a. Completes the electrical circuit by looping two wires together on its end b. Senses current on the circuit c. Creates current on the circuit d. Removes noise from the circuit

 

 

4.            A PC NIC and a switch port create one electrical circuit to use when sending data from the PC to the switch. The transmitter uses a simple encoding scheme that uses a higher amplitude to encode 1 and a lower amplitude to encode 0, sending 1 bit in each bit time. The bit rate is 2000 bits per second (2000 bps). Which of the following is true on this circuit? a. The bit time is .001 seconds. b. The bit time is .0002 seconds. c. The transmitter must change the amplitude 2000 times per second. d. The transmitter can change the amplitude 2000 times per second.

 

5.            Two nodes use an encoding scheme that cannot use one circuit to both send and receive data at the same time. The link physically contains two wires. Which of the following is a possible option to allow both nodes to send data?   a. Create two circuits, one using one wire and one using the other. b. Create one circuit, and take turns sending over that circuit. c. Create one circuit, and hope it works. d. None of the answers is correct.

 

6.            UTP cables can have up to eight wires inside the cables. Which of the following is the most likely reason why EMI from one wire does not affect the electrical behavior of another wire inside the same cable? a. The shorter the cable length, the less EMI b. Twisting the pairs together c. Shielding each wire in plastic coating d. Converting to glass fiber UTP cabling

 

 

7.            Which of the following facts are in common between both of the Ethernet standards discussed in this chapter, 10BASE-T and 100BASE-T? (Choose two answers.) a. The number of wire pairs used (2) b. The cabling pinouts used c. The speed d. The encoding scheme

 

8.            Which of the following answers best describes the definition of a cabling pinout? a. The information about the pin numbers on a connector and its matching socket b. The color of the wires and the pin numbers to which they connect on one end of a cable c. The color of the wires and the pin numbers to which they connect on both ends of a cable d. The physical cable- making act of making the wire stick out of the end of the connector, creating pins

9.            A PC NIC connects to a switch port using 100BASE-T. Which of the following is true about what happens on that link? a. The switch receives data on a circuit that includes the wire at the switch’s pin 2. b. The PC receives data on a circuit that includes the wire at the PC’s pin 7. c. The switch sends data on a circuit that includes the wire at the switch’s pin 4. d. The PC sends data on a circuit that includes the wire at the PC’s pin 3.

 

10.          With a fiber-optic cable, the core of the cable, through which light passes, is made of which of the following? a. A mix of gases b. Nothing (it’s a vacuum) c. Glass d. Cloth fibers

 

11.          Which of the following is the type of transmitter used on fiber-optic links that provides the longest maximum distances?  a. Antenna b. LED c. Laser d. Inducer

 

12.          Which one answer lists the most likely place to find a fiber-optic link in a campus Ethernet LAN? a. Between a PC and a LAN switch b. Between two switches on the same floor c. Between two switches on different floors (floors 1 and 2) d. Between two switches in different buildings in the same office park

 

13.          This chapter describes SONET, a family of physical layer standards used in telco networks over the last few decades. Which of the following are true about the slow and fast end of the

 

optical carrier (OC) standards mentioned in this book: OC-1 and OC-192? (Choose two answers.) a. OC-1 runs at approximately 52 Mbps. b. OC-1 runs at approximately 620 Mbps.

c. OC-192 runs at approximately 19.2 times the speed of OC-1. d. OC-192 runs at approximately 10,000 Mbps (10 Gbps).

 

14.          What physical medium/media do radio waves need to move from one place to another? a. Air b. The Earth’s ionosphere c. Nothing (no material/matter at all) d. None of the answers is correct.

 

15.          Fred has a smart phone and a contract with SlateRock mobile. He uses his smart phone to call his friend Barney, on Barney’s home telephone. The call works. Which of the following are not a part of the story of what happens between when Fred speaks and when Barney hears what Fred said? (Choose two answers.) a. SlateRock’s network sends the voice through the Internet. b. SlateRock’s network sends the voice to the public switched telephone network. c. Fred’s phone encodes sound waves onto a radio signal to send to the SlateRock cell tower. d. The SlateRock cell tower receives Fred’s radio signal and converts it back to bits.

 

16.          Fred has a smart phone and a contract with SlateRock mobile. He uses his smart phone to send a text to his friend Barney’s smart phone. Barney uses another mobile company. Barney gets the text and sends a text back to Fred. Which of the following is not a part of the story of what happens between when Fred sends the text and Barney sees the text? a. SlateRock’s network sends the text (as bits) through the Internet or some other data network. b. SlateRock’s network sends the text, as bits, into the PSTN. c. Fred’s phone encodes the text, as bits, onto a radio signal to send to the SlateRock cell tower. d. The SlateRock cell tower receives Fred’s radio signal and converts it back to bits.

17.          If comparing a wireless WAN to a wireless LAN, which of the components of a wireless WAN most closely matches the role and purpose of a wireless LAN access point? a. A mobile phone b. A radio tower c. The mobile company’s network d. All the other answers combined

 

18.          In a WLAN Basic Service Set (BSS), four user devices exist, labeled A, B, C, and D. A has data that it wants to send to B. Thinking of the specific steps, which of the following happens in this WLAN as part of the successful delivery of data from A to B? (Choose two answers.) a. A sends the data to the AP. b. A sends the data directly to B. c. A receives an acknowledgment from B. d. A receives an acknowledgment from the AP.

19.          A device on a WLAN just created data that it needs to send using the WLAN. Which of the following is its next step as part of the CSMA/CA algorithm used in WLANs to share a frequency? a. Listen, and if silent, send. b. Listen, and if silent, wait for 100 milliseconds. c. Listen, and if silent, wait for a random wait time. d. Do not listen, but wait for a random wait time.

20.          Which of the following are IEEE WLAN standards? (Choose three answers.) a. 802.3u b. 802.11n c. 802.11g d. 802.11a