chap1_2.docx

**Question 1** **1 / 1 pts** What is the primary function of a protocol in data communications?    To encrypt data      To amplify signals      To compress data   **Correct!**    To govern data communications     **Question 2** **1 / 1 pts** Which of the following is NOT mentioned...

**Question 1** **1 / 1 pts** What is the primary function of a protocol in data communications?    To encrypt data      To amplify signals      To compress data   **Correct!**    To govern data communications     **Question 2** **1 / 1 pts** Which of the following is NOT mentioned as a guided transmission medium? **Correct!**    Microwave      Twisted pair      Coaxial cable      Fiber optics     **Question 3** **1 / 1 pts** What is the purpose of the 4B/5B code?    To increase data transmission speed   **Correct!**    To prevent long runs of consecutive 0s      To reduce signal noise      To encrypt data     **Question 4** **1 / 1 pts** Which of the following best describes a Content Delivery Network (CDN)?    A network that connects different cellular towers      A network that provides internet access to homes   **Correct!**    A geographically distributed network of servers for efficient content distribution      A system for creating digital content     **Question 5** **1 / 1 pts** In OFDM, what is divided into many subcarriers?    Transmission power      Time slots      Data packets   **Correct!**    Channel bandwidth     **Question 6** **1 / 1 pts** Which organization proposed the OSI Reference Model?    ITU   **Correct!**    ISO      IEEE      IETF     **Question 7** **1 / 1 pts** What is the main function of switches in a switched network?    To encrypt data   **Correct!**    To create temporary connections between devices      To amplify signals      To divide the frequency spectrum     **Question 8** **1 / 1 pts** Which of the following is NOT mentioned as a component of a data communications system?    Sender      Transmission medium      Protocol   **Correct!**    Server     **Question 9** **1 / 1 pts** The primary innovation of 5G networks is: **Correct!**    Smaller cells and massive MIMO      Packet-switched core      Digital Voice      Analog transmission     **Question 10** **1 / 1 pts** In the context of network technologies, what does "internetwork" refer to?    The global Internet      A type of wireless network   **Correct!**    A collection of interconnected networks      A secure private network     **Question 11** **1 / 1 pts** What distinguishes a home network from other types of LANs?    It requires professional management      It covers a larger area      It only connects personal computers   **Correct!**    It needs to be easy to manage and secure for non-technical users     **Question 12** **1 / 1 pts** A MEO satellite is placed at an altitude of 20,000 km above the Earth's surface. Calculate the one-way signal transmission delay from the ground to the satellite (assume the signal travels at the speed of light c = 3 × 10⁸ m/s):    100 ms      133.3 ms      33.3 ms   **Correct!**    66.7 ms     **Question 13** **1 / 1 pts** What is the main function of server farms in the context of content delivery? **Correct!**    Host large volumes of content      Compress data      Encrypt data      Provide client-side caching     **Question 14** **1 / 1 pts** What is a "protocol stack"?    A type of network security measure      A physical arrangement of network devices   **Correct!**    A list of protocols used by a system, one per layer      A method for compressing network data     **Question 15** **1 / 1 pts** What is the key difference between a service and a protocol in networking?    Services are connectionless   **Correct!**    Services define operations, protocols define communication rules      Services are hardware-based      Protocols are software-based     **Question 16** **1 / 1 pts** What type of satellites are being considered for satellite-based Internet backbone networks?    MEO satellites      Geostationary satellites   **Correct!**    LEO satellites      HEO satellites     **Question 17** **1 / 1 pts** The client-server model is an example of a:    Communication protocol      Network device   **Correct!**    Resource sharing method      Network topology     **Question 18** **1 / 1 pts** In networking, what does 'throughput' primarily measure?    Network reliability      Signal strength   **Correct!**    Data transfer rate      Data accuracy     **Question 19** **1 / 1 pts** Which reference model is regularly used on the Internet?    OSI Reference Model      IEEE Reference Model      ITU Reference Model   **Correct!**    TCP/IP Reference Model     **Question 20** **1 / 1 pts** A LEO satellite system consists of 66 satellites at an altitude of 780 km. Estimate the number of satellites needed to achieve equivalent global coverage at an altitude of 1500 km:    72 satellites      48 satellites      24 satellites   **Correct!**    36 satellites     **Question 21** **1 / 1 pts** What potential issue arises from the freedom provided by computer networks?    Technological dependence      Information overload   **Correct!**    Unsolved social, political, and ethical issues      Increased productivity     **Question 22** **1 / 1 pts** Which of the following is mentioned as an example of a Metropolitan Area Network (MAN)?    Home Wi-Fi network   **Correct!**    Cable television network      Cellular network      Office Ethernet network     **Question 23** **1 / 1 pts** What is the primary innovation of 5G compared to previous generations? **Correct!**    Smaller cell sizes and massive MIMO      Analog voice transmission      Introduction of digital voice      Packet-switched core     **Question 24** **1 / 1 pts** What is the purpose of "addressing" in network layers?    To allocate network resources      To establish reliable connections   **Correct!**    To identify senders and receivers involved in a message      To encrypt data transmissions     **Question 25** **1 / 1 pts** Which technology is NOT typically used to optimize content delivery?    Server Placement   **Correct!**    Antivirus software      Caching      HTTP/2 optimization     **Question 26** **1 / 1 pts** In fiber-optic cables, what does the term "multimode" refer to? **Correct!**    Multiple beams of light moving through the core in different paths      Multiple types of connectors used      Multiple frequencies of light used      Multiple layers of cladding     **Question 27** **1 / 1 pts** What does AP stand for in the context of Wi-Fi networks?    Application Program   **Correct!**    Access Point      Access Protocol      Area Partition     **Question 28** **1 / 1 pts** Who proved that any reasonably behaved periodic function can be constructed as the sum of sines and cosines?    Claude Shannon      Harry Nyquist   **Correct!**    Jean-Baptiste Fourier      AT&T engineer   **Question 29** **1 / 1 pts** What purpose do web proxies primarily serve in a network?    Increase file size      Reduce data accuracy   **Correct!**    Improve security and performance      Encode data     **Question 30** **1 / 1 pts** Which of the following is NOT mentioned as a type of content distributed by content provider networks?    Images   **Correct!**    Text messages      Video      Audio     **Question 31** **1 / 1 pts** In network security, what does 'integrity' ensure?    High availability      Data confidentiality   **Correct!**    Data remains unaltered      User authentication     **Question 32** **1 / 1 pts** What are the two fundamental limits that nature imposes on all channels? **Correct!**    Nyquist limit and Shannon limit      Bandwidth limit and Latency limit      Frequency limit and Amplitude limit      Shannon limit and Fourier limit     **Question 33** **1 / 1 pts** Streaming stored media eliminates the need for what process?    Encryption      Compression      Encoding   **Correct!**    Downloading     **Question 34** **1 / 1 pts** In full-duplex mode, in which manner does data flow occur?    One direction only      Alternating directions   **Correct!**    Both directions simultaneously      One direction at a time     **Question 35** **1 / 1 pts** Which of the following is NOT a component of the telephone system mentioned in the text? **Correct!**    Routers      Trunks      Local loops      Switches     **Question 36** **1 / 1 pts** In mobile networks, what does a "cell" refer to?    A network protocol      A unit of data transmission      A type of mobile device   **Correct!**    A geographic area covered by a base station     **Question 37** **1 / 1 pts** Which of the following is NOT an advantage of fiber-optic cables over metallic cables?    Immunity to electromagnetic interference   **Correct!**    Bidirectional light propagation      Higher bandwidth      Less signal attenuation     **Question 38** **1 / 1 pts** Which of the following applications is typically used for MEO satellites?    Remote sensing      Weather forecasting   **Correct!**    Global Positioning System (GPS)      Satellite television     **Question 39** **1 / 1 pts** Which of the following best describes the concept of "internetworking"?    Designing web-based applications      Managing internal corporate networks   **Correct!**    Connecting different network technologies with various limitations      Implementing internet protocols     **Question 40** **1 / 1 pts** What is the process of converting between bits and signals that represent them called?    Fourier Analysis      Switching      Multiplexing   **Correct!**    Digital Modulation     **Question 41** **1 / 1 pts** What is the primary difference between a service and a protocol in networking?    Services are connectionless, while protocols are always connection-oriented   **Correct!**    Services define operations provided to upper layers, while protocols define rules for peer entity communication      Services are only used in lower layers, while protocols are used in upper layers      Services are implemented in hardware, while protocols are implemented in software     **Question 42** **1 / 1 pts** Which group was created to oversee people interested in the Internet?    IAB      IRTF      ARPANET Committee   **Correct!**    Internet Society     **Question 43** **1 / 1 pts** Which type of service is modeled after the telephone system? **Correct!**    Connection-oriented service      Unreliable service      Datagram service      Connectionless service     **Question 44** **1 / 1 pts** What distinguishes wireless local area networks (WLANs) from cellular networks?    WLANs use radio waves for communication      WLANs provide internet access      WLANs support mobile devices   **Correct!**    WLANs cover a smaller geographic area     **Question 45** **1 / 1 pts** What is the primary function of ISO in the world of standards?    Developing Internet protocols      Regulating telecommunications   **Correct!**    Producing and publishing international standards      Managing the World Wide Web     **Question 46** **1 / 1 pts** What is the process of converting analog audio to digital audio called? **Correct!**    ADC      DDC      DAC      DACD     **Question 47** **1 / 1 pts** What is the primary function of the physical layer in networking?    To define protocols for data transmission   **Correct!**    To define electrical and timing interfaces for sending bits as signals      To route data packets      To encrypt data for secure transmission     **Question 48** **1 / 1 pts** Which of the following best describes a Wide Area Network (WAN)?    A network limited to a city      A network connecting personal devices      A network covering a single building   **Correct!**    A network spanning a large geographical area     **Question 49** **1 / 1 pts** In the context of network security, what does "integrity" primarily refer to? **Correct!**    Preventing surreptitious changes to messages      Ensuring data remains confidential during transmission      Authenticating the identity of users      Preventing unauthorized access to data     **Question 50** **1 / 1 pts** What is a key characteristic of wired broadband access networks?    They use radio waves for communication   **Correct!**    They use a physical medium like copper or fiber optic cables      They provide connectivity to mobile devices      They are operated by mobile network operators     **Question 51** **1 / 1 pts** What is the main purpose of compressing digital audio?    Increase volume      Enhance clarity   **Correct!**    Reduce file size      Improve quality     **Question 52** **1 / 1 pts** What is NOT mentioned as a principle for creating layers in the OSI model? **Correct!**    The number of layers should be as large as possible      Layer boundaries should minimize information flow across interfaces      Each layer should perform a well-defined function      A layer should be created where a different abstraction is needed     **Question 53** **1 / 1 pts** Which technology is primarily used by organizations to manage and optimize network traffic across multiple locations? **Correct!**    SD-WAN      LAN      PAN      VPN     **Question 54** **1 / 1 pts** What was the main characteristic of 1G mobile networks? **Correct!**    Analog transmission      CDMA technology      Digital transmission      Packet-switched core     **Question 55** **1 / 1 pts** Which of the following is NOT mentioned as a form of data representation in the text?    Text      Video   **Correct!**    3D      Audio     **Question 56** **1 / 1 pts** What does 'jitter' specifically refer to in the context of data communications?    Unauthorized access      Data corruption   **Correct!**    Variation in packet arrival times      Signal interference     **Question 57** **1 / 1 pts** Which of the following is a disadvantage of fiber-optic cables?    Low bandwidth      Heavyweight      High susceptibility to electromagnetic interference   **Correct!**    Higher installation and maintenance costs     **Question 58** **1 / 1 pts** What is the main function of the physical layer?    Encrypt data   **Correct!**    Define physical connections      Control flow      Manage addresses     **Question 59** **1 / 1 pts** What is the primary difference between multimode step-index and multimode graded-index fiber?    The number of light beams used   **Correct!**    The density change in the core      The material of the core      The thickness of the cladding     **Question 60** **1 / 1 pts** What does PSTN stand for? **Correct!**    Public Switched Telephone Network      Private Secure Transmission Network      Public Secure Telephone Node      Private Switched Transmission Node     **Question 61** **1 / 1 pts** Which factor does NOT significantly affect the quality of digital video?    Frame rate      Resolution      Bit rate   **Correct!**    Compression type     **Question 62** **1 / 1 pts** Which generation of mobile networks first shifted to all packet-switched cores?    3G      2G      5G   **Correct!**    4G     **Question 63** **1 / 1 pts** In the context of network layers, what are "peers"?    Adjacent layers in the same system   **Correct!**    Entities in corresponding layers on different machines      Protocols in the same layer      Interfaces between layers     **Question 64** **1 / 1 pts** Which component of a data communications system represents the information to be communicated?    Protocol      Receiver   **Correct!**    Message      Sender     **Question 65** **1 / 1 pts** What is the primary characteristic of Personal Area Networks (PANs)?    They require wired connections      They are used for citywide communication   **Correct!**    They connect devices in close proximity to an individual user      They cover a large geographical area     **Question 66** **1 / 1 pts** Which type of connector is most commonly used with coaxial cables today?    ST      RJ-45   **Correct!**    BNC      FC     **Question 67** **1 / 1 pts** Which of the following is NOT typically considered a broadband access network technology?    Wi-Fi      Cellular networks      Fiber optic cables   **Correct!**    Original Ethernet LAN     **Question 68** **1 / 1 pts** What does UTP stand for in the context of network cables?    Universal Transmission Protocol      Ultra-Thin Protocol   **Correct!**    Unshielded Twisted Pair      Unified Twisted Pair     **Question 69** **1 / 1 pts** What aspect of network security involves implementing policies for recovery from breaches? **Correct!**    Security      Reliability      Performance      Accessibility     **Question 70** **1 / 1 pts** Which of the following is NOT a primary function of content provider networks?    Distributing digital content efficiently      Balancing load across multiple servers      Reducing latency for content delivery   **Correct!**    Providing internet access to end-users     **Question 71** **1 / 1 pts** Which of the following is NOT typically a component of enterprise networks? **Correct!**    Personal Area Networks (PANs)      Wide Area Networks (WANs)      Local Area Networks (LANs)      Wireless networks     **Question 72** **1 / 1 pts** Which organization is responsible for developing Web standards?    ISO      IETF      IEEE   **Correct!**    W3C     **Question 73** **1 / 1 pts** Which type of transmission occupies a band of frequencies around the frequency of the carrier signal?    Broadband transmission   **Correct!**    Passband transmission      Baseband transmission      Narrowband transmission     **Question 74** **1 / 1 pts** In video compression, what are consecutive frames often used to represent? **Correct!**    Motion and changes      Audio tracks      Text overlays      Static images     **Question 75** **1 / 1 pts** Which of the following is NOT a sector of ITU?    ITU-R      ITU-T      ITU-D   **Correct!**    ITU-S     **Question 76** **1 / 1 pts** In a switched network, what are the interlinked nodes called?    Hubs      Repeaters   **Correct!**    Switches      Routers     **Question 77** **1 / 1 pts** A LEO satellite orbits the Earth at an altitude of 1000 km. Assuming the Earth is a sphere with a radius of 6371 km, calculate the time it takes for the satellite to complete one orbit (take g = 9.8 m/s²):    120 minutes      90 minutes      135 minutes   **Correct!**    105 minutes     **Question 78** **1 / 1 pts** What is the primary purpose of network protocols? **Correct!**    To define rules for data transmission and processing between devices      To encrypt all network traffic      To physically connect network devices      To increase network speed     **Question 79** **1 / 1 pts** Which multiplexing technique divides the spectrum into frequency bands for different users? **Correct!**    Frequency Division Multiplexing (FDM)      Time Division Multiplexing (TDM)      Orthogonal Frequency Division Multiplexing (OFDM)      Code Division Multiplexing (CDM)     **Question 80** **1 / 1 pts** Which mobile network generation is based on broadband CDMA? **Correct!**    3G      5G      4G      2G     **Question 81** **1 / 1 pts** Which network type is most likely to use base stations to provide coverage?    Content provider networks      Broadband access networks      Transit networks   **Correct!**    Mobile networks     **Question 82** **1 / 1 pts** Who extended Nyquist's work on channel capacity to include the case of random noise? **Correct!**    Claude Shannon      Harry Nyquist      AT&T engineer    Jean-Baptiste Fourier     **Question 83** **1 / 1 pts** What does 'jitter' refer to in data communications?    Unauthorized data access   **Correct!**    Variation in packet arrival time      Packet loss in the network      Data corruption during transmission     **Question 84** **1 / 1 pts** Which satellite system is an example of MEO satellites?    Iridium      Starlink   **Correct!**    GPS      Geostationary satellites     **Question 85** **1 / 1 pts** In which mode of data flow can both devices transmit and receive simultaneously?    Simplex      Half-duplex      Quadruplex   **Correct!**    Full-duplex     **Question 86** **1 / 1 pts** Which of the following is NOT mentioned as a design goal for network protocols?    Reliability   **Correct!**    Portability      Evolvability      Resource allocation     **Question 87** **1 / 1 pts** What is the approximate orbital period of MEO satellites? **Correct!**    6 hours      24 hours      12 hours      1 hour     **Question 88** **1 / 1 pts** Which type of connection allows more than two devices to share a single link?    Broadcast   **Correct!**    Multipoint      Unicast      Point-to-point     **Question 89** **1 / 1 pts** Which mode of data flow allows communication in both directions but not simultaneously? **Correct!**    Half-duplex      Full-duplex      Simplex      Bi-simplex     **Question 90** **1 / 1 pts** In which frequency band do 802.11 (Wi-Fi) systems typically operate? **Correct!**    Unlicensed ISM bands      Licensed cellular bands      Satellite communication bands      AM radio bands     **Question 91** **1 / 1 pts** What is the maximum distance a signal can typically travel in a fiber-optic cable without requiring regeneration?    5 km   **Correct!**    50 km      10 km      30 km     **Question 92** **1 / 1 pts** What type of standard is created without a formal plan?    De jure standard      ISO standard      ITU standard   **Correct!**    De facto standard     **Question 93** **1 / 1 pts** Compared to a Local Area Network (LAN), the Internet covers a much:    Slower data transfer rate      Smaller geographical area      More limited range of applications   **Correct!**    Wider geographical area     **Question 94** **1 / 1 pts** MPEG, H.264, and HEVC are standards for what type of digital content?    Text Compression      Image compression   **Correct!**    Video compression      Audio compression     **Question 95** **1 / 1 pts** Which of the following is NOT a fundamental characteristic of an effective data communications system?    Delivery      Accuracy   **Correct!**    Bandwidth      Timeliness     **Question 96** **1 / 1 pts** What configuration do multipoint connections in networking allow for?    One-to-one links      Unicast transmission   **Correct!**    Shared links among multiple devices      Point-to-point connections     **Question 97** **1 / 1 pts** What is the primary advantage of wireless broadband access networks? **Correct!**    Mobility and flexibility      Lower latency      Higher data transfer rates      Better security     **Question 98** **1 / 1 pts** E-commerce refers to:    Sending and receiving emails      Sharing software applications over a network      Video conferencing between multiple users   **Correct!**    Electronic business transactions     **Question 99** **1 / 1 pts** What is a key feature of cellular networks? **Correct!**    They divide coverage areas into cells      They provide only voice services      They use fiber optic cables for communication      They operate only in licensed frequency bands     **Question 100** **1 / 1 pts** Compared to GEO (Geosynchronous Earth Orbit) satellites, which of the following advantages do LEO satellites have?    Wider coverage   **Correct!**    Lower latency      Longer lifespan      Less affected by ionospheric interference