REM B LVL 1 Flashcards by Dave Molina

A sine wave in the ___ domain can be
represented by one single spike in the ___ domain.

A. time; phase
B. phase; time
C. time; frequency
D. frequency; time

C. time; frequency

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Data from a computer are ___ : the
local loop handles ____ signals.

A. Analog; analog
B. Digital; analog
C. Analog; digital
D. Digital; digital

B. Digital; analog

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In a digital system, the ___
is controlled by the computer

A. power supply
B. antenna
C. input/output
D. transceiver

C. input/output

The Digital Station block diagram: Input/Output, Computer, MODEM, Transceiver, Antenna.

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A modulated signal is formed by

A. Quantization of the source data
B. Sampling at the Nyquist frequency
C. Changing the carrier wave by the
modulating signal
D. Changing the modulating signal by the
carrier wave

C. Changing the carrier wave by the
modulating signal

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The bandwidth of an FM signal requires
10 times the bandwidth of the ___ signal.

A. Modulating
B. Bipolar
C. Sampling
D. Carrier

A. Modulating

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A signal not modulated onto an RF carrier. In video, refers to the visual signal as it is handled before being modulated onto an RF carrier.

A. Cross Modulation
B. Broadband
C. Composite Second Order
D. Baseband

D. Baseband

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If the available channel is a ___
channel, we cannot send a digital signal
directly to the channel.

A. low rate
B. low-pass
C. high rate
D. bandpass

D. bandpass

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The most widely used data
communication code is the 7-bit binary
code known as the

A. Morse code
B. Extended Binary Coded Decimal
Interchange Code (EBCDIC)
C. Baudot Code
D. American Standard Code for
Information Interchange (ASCII)

D. American Standard Code for
Information Interchange (ASCII)

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What do you call the result when the
input to the ADC is changing while it is
performing the conversion?

A. Aperture Distortion
B. Quantization
C. None of these choices
D. Insertion Loss

A. Aperture Distortion

If the input to the ADC

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PCM is an example of ___ conversion.

A. Digital-to-digital
B. Analog-to-Digital
C. Digital-to-analog
D. Analog-to-analog

B. Analog-to-Digital

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Commonly called the Manchester Code and specified in lEEE standard 802.3 for Ethernet local area networks

A. Biphase M
B. Digital Biphase
C. Biphase L
D. Biphase

C. Biphase L

Biphase L - commonly called the
Manchester Code and specified in lEEE standard 802.3 for Ethernet local area networks

Biphase M - used for encoding
SMPTE(Society of Motion Picture and
Television Engineers) time-code data for
recording on videotapes

Biphase - it uses one cycle of a square wave at 0° phase to represent logic 1 and one cycle of a square wave at 180°phase to represent logic 0

Digital Biphase - a popular type of line encoding that produces a strong timing component for clock recovery and does not cause dc wandering

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Uses one cycle of a square wave at 0°
phase to represent logic 1 and one cycle
of a square wave at 180° phase to
represent a logic 0

A. Biphase M
B. Biphase L
C. Digital Biphase
D. Biphase

D. Biphase

Biphase L - commonly called the
Manchester Code and specified in lEEE standard 802.3 for Ethernet local area networks

Biphase M - used for encoding
SMPTE(Society of Motion Picture and
Television Engineers) time-code data for
recording on videotapes

Biphase - it uses one cycle of a square wave at 0° phase to represent logic 1 and one cycle of a square wave at 180°phase to represent logic 0

Digital Biphase - a popular type of line encoding that produces a strong timing component for clock recovery and does not cause dc wandering

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What do you call a circuit that
periodically samples the analog input
signal and converts those samples to a
multilevel PAM signal?

A. None of these choices
B. Sample-and-Hold Circuit
C. Sampling Circuit
D. MCU

B. Sample-and-Hold Circuit

Sample-and-hold circuit is a circuit that
periodically samples the analog input
signal and converts those samples to a
multilevel PAM signal.

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Which is used to protect privacy of the
information?

A. Source coding
B. Cipher coding
C. None of these Choices
D. Compression coding

B. Cipher coding

Cipher coding is used to provide privacy
for the information.

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In a digital system, the transceiver is
connected to the ___

A. input/output
B. computer
C. scanner
D. modem

D. modem

The Digital Station block diagram: Input/Output, Computer, MODEM, Transceiver, Antenna.

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Another term used to express the data
speed in digital communication
systems is ___

A. Baud rate
B. Sampling rate
C. Flow rate
D. Bit rate

A. Baud rate

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Which modulation technique involves tribits, eight different phase shifts, and one amplitude?

A. ASK
B. 8-PSK
C. FSK
D. 4-PSK

B. 8-PSK

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What refers to the accuracy and speed
with which information, whether it is
voice or video, analog or digital, is sent
and received over communication
media?

A. Information efficiency
B. Transmission efficiency
C. System efficiency
D. Coding efficiency

B. Transmission efficiency

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When an ASK signal is decomposed, the
result is ___

A. Always one sine wave
B. An infinite number of sine waves
C. None of these choices
D. Always two sine waves

B. An infinite number of sine waves

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What is the oldest and simplest form of
modulation used in modems?

A. Orthogonal frequency division multiplexing
(OFDM)
B. Frequency-shift keying (FSK)
C. Phase-shift keying (PSK)
D. Quadrature amplitude modulation (QAM)

B. Frequency-shift keying (FSK)

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The bit rate always equal the baud rate
in which type of signal?

A. FSK
B. 4-PSK
C. QAM
D. All of these choices

A. FSK

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For a given bit rate, the minimum
bandwidth for ASK is ___ the
minimum bandwidth for FSK.

A. Greater than
B. Equivalent to
C. Twice
D. Less than

D. Less than

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In a binary laser transmitter, the ratio between the maximum light output in one binary state, to the minimum light output on the other binary state.

A. Fabry-Perot ratio
B. Failure rate
C. Extinction ratio
D Bit error rate

C. Extinction ratio

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Which of the following is most
affected by noise?

A. FSK
B. QAM
C. PSK
D. ASK

D. ASK

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The QPSK modulator consists of a 2-bit shift register implemented with flip flops, commonly known as a ___ A. chip code generator B. latch C. diplexer D. bit splitter

D. bit splitter

At the CRC checker ___ means that the data unit is damaged. A. A string of 1s B. A nonzero remainder C. A string of alternating 1s and 0s D. A string of 0s

B. A nonzero remainder

CRC uses A. Multiplication & Binary division B. Multiplication C. None of these Choices D. Binary division

A. Multiplication & Binary division CRC uses both multiplication and binary division.

A measurement of the quality of a digital modulated signal, which defines the average error between the proper location of all points in the constellation and their actual location. A. Optical modulation index (OMI) B. Modulation error ratio (MER) C. Modal dispersion D. Peak-to-average ratio

B. Modulation error ratio (MER)

How error detection and correction is done? A. By passing it through equalizer B. By adding redundancy bits C. By amplifying it D. By passing it through filter

B. By adding redundancy bits Error can be detected and corrected by adding additional information that is by adding redundancy bits.

The Hamming code is a method of A. Error detection B. Error correction C. Error and Error correction D. Error encapsulation

C. Error and Error correction

In the ___ random-access method there is no collision. A. Token-passing B. CSMA/CD C. ALOHA D. CSMA/CA

D. CSMA/CA

A technique for putting more signals on a return optical path by converting some incoming signals to alternate frequency bands. A. Bit stuffing B. Direct pick-up C. Block conversion D. Digital return

C. Block conversion

In either coaxial FDM or optical WDM systems, a situation in which information on one carrier is present in the demodulated signal from another carrier. A. Composite second order (CSO) B. Crosstalk C. Composite triple beat (CTB) D. Chroma-luma delay

B. Crosstalk

What do you call a signaling bit in frame 18? A. A bit B. C bit C. D bit D. B bit

B. C bit A bit - signaling bit in frame 6 B bit - signaling bit in frame 12 C bit - signaling bit in frame 18 D bit - signaling bit in frame 24

What do you call a signaling bit in frame 6? A. B bit B. D bit C. C bit D. A bit

D. A bit A bit - signaling bit in frame 6 B bit - signaling bit in frame 12 C bit - signaling bit in frame 18 D bit - signaling bit in frame 24

Guard bands increase the bandwidth for A. FDM B. FDM and TDM C. None of these choices D. TDM

A. FDM

What do you call a signaling bit in frame 12? A. B bit B. C bit C. D bit D. A bit

A. B bit A bit - signaling bit in frame 6 B bit - signaling bit in frame 12 C bit - signaling bit in frame 18 D bit - signaling bit in frame 24

Multicarrier modulation (MCM) is also known as_ A. QPSK B. FSK C. OFDM D. QAM

C. OFDM

In asynchronous transmission, one or more bits to indicate the end of transmission A. stop bit B. escape byte C. flag D. trailer

A. stop bit

What is another name for discrete multitone (DMT)? A. Frequency-shift keying (FSK) B. Quadrature Amplitude Modulation (QAM) C. Orthogonal frequency division multiplexing (OFDM) D. Carrierless Amplitude and Phase (CAP)

C. Orthogonal frequency division multiplexing (OFDM)

Moving signals from one line to another is called: A. space switching B. cross-point switching C. line switching D. time switching

A. space switching

This is the main cabling of a network that all of the segment connects to. Usually, this is capable of carrying more information than the individual segments. A. Topology B. Backbone C. Node D. Main Segment

B. Backbone

The way each node is physically connected to the network is called: A. Segment B. Topology C. Network Architecture D. Backbone

B. Topology

What does "network" mean in packet radio? A. The connections on terminal-node controllers B. A way of connecting terminal-node controllers by telephone so data can be sent over long distances C. The programming in a terminal-node controller that rejects other callers if a station is already connected D. A way of connecting packet-radio stations so data can be sent over long distances

D. A way of connecting packet-radio stations so data can be sent over long distances In packet radio operation, a 'network' is a succession of digipeaters (or normal packet stations which can also digipeat') used to connect to a station normally not within range of the originating station.

Frequency of failure and network recovery time after a failure are measures of the ___ of a network. A. Security B. Feasibility C. Reliability D. Performance

C. Reliability

A common topology, where each node is chained (connected one right after the other) along the same backbone.Information sent from a node travels along the backbone until it reaches its destination node. A. Star B. Bus C. Ring D. Mesh

B. Bus

An IP address consists of ___ bits. A. 8 B. Any of these choices C. 4 D. 32

D. 32

It refers to a measure of the effectiveness and efficiency of computer-based devices to communicate and share information and messages without human intervention. It is achieved by the use of communication protocol standards. A. Efficiency B. Connectivity C. High Speed D. High data rate

B. Connectivity

Which of the following is essential for communications? A. Message must be understood B. Message must have a medium C. All of the choices are correct D. Message must have a receiver

C. All of the choices are correct

Networks need to interconnect at a distance by a form of what? A. point to multipoint B. none of these choices C. point to point D. both point to point and point to multipoint

D. both point to point and point to multipoint

Which kind of data network topology requires a workstation or terminal to receive first supervisory frame before said device starts transmitting? A. Star B. Mesh C. Bus D. Ring

D. Ring

A common topology where each node is connected to a central device called a hub (host computer). The hub takes a signal that comes from any node and passes it along to all the other nodes in the network. A. Mesh B. Star C. Ring D. Bus

B. Star

The ____ rate defines the number of data elements sent in 1s; the ____ rate is the number of signal elements sent in 1s. A. none of these choices B. baud; bit C. signal; data D. data; signal

D. data; signal

Refers to the number of discrete signal elements (bands) transmitted per sec. A. Band Rate B. None of the choices C. Bit rate D. Band Width

A. Band Rate

A common topology where nodes are chained, but the end of the network comes back around to the first node, creating a complete circuit. A. Star B. Mesh C. Bus D. Ring

D. Ring

It is the physical path between transmitter and receiver in a data transmission system. A. Vacuum B. Data C. Medium D. Protocol

C. Medium

A transmission mode that can transmit data in both the directions but transmits in only one direction at a time. A. simplex B. full duplex C. half duplex D. semi-duplex

C. half duplex The half duplex mode supports two way traffic but only in one direction at a time.The interactive transmission of data within a time sharing system may be best suited to half-duplex lines.

Transmission media are closest to the ___ layer A. Physical B. Application C. Network D. Transport

A. Physical

In a data transmission system, the medium provides the physical path between transmitter and receiver. It could be conductive, electromagnetic,light or wireless. Which of the following does not belong to a group? A. Microwave B. Optical Fiber C. Twisted Pair D. Coaxial cables

A. Microwave

Transmission or channels in data communications include: A. radio waves B. Satellites C. All of the choices are correct D. Telephone lines

C. All of the choices are correct

In ____ transmission, bits are transmitted simultaneously, each across its own wire. A. Synchronous serial B. Asynchronous serial and Synchronous serial C. Parallel D. Asynchronous serial

C. Parallel

In ___ transmission, a start bit and stop bit frame a character byte. A. Synchronous serial B. Asynchronous serial and Synchronous serial C. Parallel D. Asynchronous serial

D. Asynchronous serial

The choice of communication channel depends on several factors, of which data transmission speed is relatively important. Data transmission speed depends on which of the following? A. Band Width B. Both Band Width and Band Rate C. None of these choices D. Band Rate

B. Both Band Width and Band Rate

In ___ transmission, bits are transmitted over a single wire, one at a time. A. Asynchronous serial B. Asynchronous serial and Synchronous serial C. Parallel D. Synchronous serial

B. Asynchronous serial and Synchronous serial

In cable modems, the signal from the cable passes through the ____, which is a filter circuit that permits simultaneous transmit and receive operations. A. Synthesizer B. Duplexer C. Diplexer D. Amplifier

B. Duplexer

Which of the following isnt a type of transmission mode? A. physical B. full duplex C. half duplex D. simplex

A. physical There are three modes of transmission: simplex, half duplex and full duplex. Transmission modes tell the direction of signal flow between two devices.

When a high-speed data is transmitted over a communication link, whether it is wired or wireless, errors are inevitable. Which process is used to remedy this by adding extra bits to the data characters before transmitting the data stream? A. Encoding B. Decoding C. Correction D. Enhancement

A. Encoding

A term that defines the direction of flow of information between devices. A. interconnectivity B. transmission C. transmission mode D. intra connectivity

C. transmission mode The term transmission mode defines the direction of flow of information between two communication devices. It tells the direction of signal flow.

What multiplexing technique where individual messages are transferred to a new position in the spectral range? A. Amplitude B. Time C. Phase D. Frequency

D. Frequency

Which describes the ability of two or more computer of different vendors being able to transmit and receive data and carry out processes as expected by the users? A. Inter-workability B. Inter-changeability C. Inter-operability D. Inter-compatibility

C. Inter-operability

One of the most widely used systems, in which each character transmitted contains one additional bit, known as a A. Parity B. Hamming C. Redundancy D. Reed Solomon

A. Parity

Block coding can help in ____ at the receiver. A. Attenuation B. Synchronizations and Error detection C. Error detection D. Synchronizations

B. Synchronizations and Error detection

In cyclic redundancy checking, the divisor is ___ the CRC. A. 1 bit more than B. 2 bits more than C. The same size as D. 1 bit less than

A. 1 bit more than

An unauthorized user is a network ___ issue. A. Reliability B. Performance C. All of these choices D. Security

D. Security

Which of the following encoding methods does not provide for synchronization? A. RZ B. Manchester C. NRZ-L D. NRZ-I

C. NRZ-L

The sharing of a medium and its link by two more devices is called ___ A. Multiplexing B. Line Encoding C. Encoding D. Modulation

A. Multiplexing

In data communications, the process of scrambling of data to protect the privacy of the transmitted signal A. Decryption B. Encryption C. Compression D. Locking

B. Encryption Decryption is the reconversion of encrypted data to its original form Compression is the amplification of a signal in such a way that there is less gain for higher input signals than for lower-level input signals

A device used to interconnect SIMILAR networks, e.g. similar protocols and workstations and servers. A. Gateway B. Server C. Router D. Bridge

C. Router

In OSI Model, this layer deals with the form and syntax of the message. A. Application B. Transport C. Session D. Presentation

D. Presentation

As the data packet moves from the upper to the lower layers, headers are A. Rearranged B. Added C. Removed D. Modified

B. Added

The ___ address identifies a process on a host. A. port B. physical C. IP D. specific

A. port

A ____ is actually a multiport repeater. A. VLAN B. Router C. Hub D. Bridge

C. Hub

TCP/IP is a ___ hierarchical protocol suite developed ___ the OSI model. A. five-layer; after B. six-layer; before C. seven-layer; before D. five-layer; before

D. five-layer; before

Web sites can be located with an address that must conform to a specific format to ensure successful communications. What do you call this address of the site or file on the internet? A. HTTP (Hypertext Transfer Protocol) B. HTML (Hypertext Markup Language) C. Domain D. URL (Uniform Resource Locator)

D. URL (Uniform Resource Locator)

It is an approved reference model and protocol determined by standard setting groups for building or developing products and services. A. Blueprint B. Standard C. Reference D. Communication protocol

B. Standard

Under the Open System Interconnection hierarchical model, which of the 7 layers are responsible in allowing interoperability among unrelated software systems? A. Layers 4-6 B. Layers 3-4 C. Layers 5-7 D. Layers 1-3

C. Layers 5-7

The Internet model consists of ___ layers. A. Seven B. Three C. Five D. Eight

C. Five

When a host on network A sends a message to a host on network B, which address does the router look at? A. logical B. none of these choices C. physical D. port

A. logical

___ is a multiport bridge that provides bridging function. A. Switch B. Hub C. Repeater D. Router

A. Switch

___ is a device which operates in the Network layer and it makes forwarding decisions on the basis of network addresses. A. Switch B. Hub C. Router D. Repeater

C. Router

In OSI model, the physical connections and electrical standards for the communication system are defined here. A. Data Link B. Transport C. Network D. Physical

D. Physical

This allows the user to use a mouse to point and click on text, drawings and pictures to facilitate an internet search. A. Web Browser B. Uniform resource locator C. Internet service provider D. Search engine

A. Web Browser

ISDN stands for ___ A. Integrated Services Digital Network B. Integrated Services Discrete Node C. Integrated Services Digital Node D. Integrated Services Discrete Network

A. Integrated Services Digital Network ISDN stands for integrated services digital network. It defines the dedicated signalling network that has been created to complement the PSTN for more flexible and efficient network access and signalling.

This is created if the LANs are connected across a region. A. Personal Area Networks (PAN) B. Wide Area Networks (WAN) C. Metropolitan Area Networks (MAN) D. Campus Area Networks (CAN)

B. Wide Area Networks (WAN)

LANs, MANs, WANs require a technology that allows fast communication of the signals. ____ is the common LAN technology. It is based on a bus topology in which computers share the same cable to send data. A. Bit net B. Fidonet C. internet D. Ethernet

D. Ethernet

The ____ address, also known as the link address, is the address of a node as defined by its LAN or WAN. A. port B. IP C. physical D. specific

C. physical

The bridge with the least-cost path between the LAN and the root bridge is called the ___ bridge. A. Forwarding B. Designated and Forwarding C. Blocking D. Designated

D. Designated

Data communication system within a building or campus is ___ A. WAN B. LAN C. PAN D. MAN

B. LAN Network. This network interconnects computers in a small area such as schools, offices, residence etc. It is the most versatile kind of data communication system where most of the computer network concepts can be visibly used.

A network of computers that are in the same general physical location, within a building or a campus are linked through a topology. A. Personal Area Networks (PAN) B. Wide Area Networks (WAN) C. Local Area Networks (LAN) D. Metropolitan Area Networks (MAN)

C. Local Area Networks (LAN)

It interconnects a number of (LANs) using a high-capacity backbone technology and provides up-link services to WANs and the internet. A. Wide Area Networks (WAN) B. Metropolitan Area Networks (MAN) C. Personal Area Networks (PAN) D. Local Area Networks (LAN)

B. Metropolitan Area Networks (MAN)