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All Electronics & Telecommunication MCQs

Browse Electronics & Telecommunication Engineering MCQs with four options, hidden answers, concise explanations and references where available. Questions are organized in pages of up to 100 for focused practice.

Question 1201
Power ElectronicsHarmonics

Total harmonic distortion (THD) is a measure of?

  • AHarmonic content relative to the fundamental component
  • BOnly DC input voltage
  • CSemiconductor junction temperature
  • DGate resistance
Report an error
Correct Answer: A. Harmonic content relative to the fundamental component
Explanation: THD quantifies the RMS contribution of harmonics relative to the RMS fundamental component.
Reference: Standard power electronics: harmonics
Question 1202
Power ElectronicsPWM Inverters

An output filter at a PWM inverter is mainly used to?

  • AAttenuate switching-frequency harmonics
  • BIncrease semiconductor layer count
  • CGenerate gate pulses
  • DEliminate the DC source
Report an error
Correct Answer: A. Attenuate switching-frequency harmonics
Explanation: The filter passes the desired low-frequency fundamental while reducing high-frequency switching components.
Reference: Standard power electronics: pwm inverters
Question 1206
Power ElectronicsDevice Selection

For high-voltage, high-power switching at moderate switching frequency, which device is commonly a suitable fully controllable choice?

  • AIGBT
  • BDIAC
  • CUncontrolled power diode
  • DConventional SCR with no turn-off circuit in every case
Report an error
Correct Answer: A. IGBT
Explanation: IGBTs are widely used where substantial voltage/current capability and gate-controlled turn-on/turn-off are required at moderate switching frequencies.
Reference: Standard power electronics: device selection
Question 1207
Power ElectronicsPower Factor

A controlled rectifier drawing a highly non-sinusoidal and phase-delayed input current can have reduced input power factor due to?

  • ABoth displacement and distortion effects
  • BOnly transformer turns ratio
  • COnly DC load resistance
  • DAntenna radiation loss
Report an error
Correct Answer: A. Both displacement and distortion effects
Explanation: Converter input power factor can be degraded by phase displacement of the fundamental current and by harmonic distortion of the input current waveform.
Reference: Standard power electronics: power factor
Question 1208
Computer & Networking BasicsComputer Fundamentals

CPU stands for?

  • ACentral Processing Unit
  • BComputer Primary Utility
  • CCentral Program User
  • DControl Processing Utility
Report an error
Correct Answer: A. Central Processing Unit
Explanation: CPU stands for Central Processing Unit and executes instructions while coordinating major processing operations.
Reference: Standard computer and networking fundamentals: computer fundamentals
Question 1210
Computer & Networking BasicsComputer Fundamentals

Which CPU component directs and coordinates the execution of instructions?

  • AControl Unit
  • BHard disk
  • CMonitor
  • DNetwork cable
Report an error
Correct Answer: A. Control Unit
Explanation: The control unit interprets instructions and coordinates operations within the processor and other system components.
Reference: Standard computer and networking fundamentals: computer fundamentals
Question 1213
Computer & Networking BasicsComputer Memory

Which memory is normally the fastest among these?

  • ACPU register
  • BMain RAM
  • CSSD
  • DHard disk drive
Report an error
Correct Answer: A. CPU register
Explanation: Registers are located within the CPU and provide extremely fast storage for operands, addresses and intermediate results.
Reference: Standard computer and networking fundamentals: computer memory
Question 1214
Computer & Networking BasicsComputer Memory

Cache memory is mainly used to?

  • AReduce the average time needed by the CPU to access frequently used data and instructions
  • BReplace all secondary storage permanently
  • CProvide internet connectivity
  • DConvert analog signals to digital
Report an error
Correct Answer: A. Reduce the average time needed by the CPU to access frequently used data and instructions
Explanation: Cache stores frequently or recently used information close to the CPU, reducing average memory-access latency.
Reference: Standard computer and networking fundamentals: computer memory
Question 1215
Computer & Networking BasicsData Representation

One byte contains how many bits?

  • A4
  • B8
  • C16
  • D32
Report an error
Correct Answer: B. 8
Explanation: A byte is conventionally defined as 8 bits.
Reference: Standard computer and networking fundamentals: data representation
Question 1216
Computer & Networking BasicsData Representation

A binary digit can have which values?

  • A0 or 1
  • B0 to 7
  • C0 to 9
  • DA to F only
Report an error
Correct Answer: A. 0 or 1
Explanation: A bit is a binary digit and has two possible values: 0 and 1.
Reference: Standard computer and networking fundamentals: data representation
Question 1219
Computer & Networking BasicsOperating Systems

An operating system primarily acts as an interface between?

  • AUsers/applications and computer hardware
  • BTwo resistors only
  • CAntenna and free space
  • DTransformer windings
Report an error
Correct Answer: A. Users/applications and computer hardware
Explanation: An operating system manages hardware resources and provides services/interfaces for users and application software.
Reference: Standard computer and networking fundamentals: operating systems
Question 1220
Computer & Networking BasicsOperating Systems

Which of the following is an example of an operating system?

  • ALinux
  • BHTML
  • CHTTP
  • DEthernet cable
Report an error
Correct Answer: A. Linux
Explanation: Linux is an operating system; HTML is a markup language and HTTP is an application-layer protocol.
Reference: Standard computer and networking fundamentals: operating systems
Question 1221
Computer & Networking BasicsNetworking Fundamentals

A computer network is a collection of interconnected devices that can?

  • AExchange data and share resources
  • BOnly perform isolated calculations
  • COperate without any communication medium or protocol
  • DConvert AC to DC
Report an error
Correct Answer: A. Exchange data and share resources
Explanation: Networks connect devices so they can communicate and share data, services and resources.
Reference: Standard computer and networking fundamentals: networking fundamentals
Question 1222
Computer & Networking BasicsNetwork Types

LAN stands for?

  • ALocal Area Network
  • BLong Access Node
  • CLogical Analog Network
  • DLarge Antenna Network
Report an error
Correct Answer: A. Local Area Network
Explanation: LAN means Local Area Network, typically covering a limited area such as a building, office or campus.
Reference: Standard computer and networking fundamentals: network types
Question 1223
Computer & Networking BasicsNetwork Types

WAN stands for?

  • AWide Area Network
  • BWireless Access Number
  • CWired Analog Node
  • DWeb Application Name
Report an error
Correct Answer: A. Wide Area Network
Explanation: WAN means Wide Area Network and spans larger geographic areas than a typical LAN.
Reference: Standard computer and networking fundamentals: network types
Question 1225
Computer & Networking BasicsNetworking Devices

An Ethernet switch primarily forwards frames using?

  • AMAC addresses
  • BOnly domain names
  • CCPU clock frequency
  • DFile extensions
Report an error
Correct Answer: A. MAC addresses
Explanation: A Layer-2 Ethernet switch learns MAC addresses and uses its forwarding table to send frames toward the appropriate port.
Reference: Standard computer and networking fundamentals: networking devices
Question 1226
Computer & Networking BasicsNetworking Devices

A repeater is mainly used to?

  • ARegenerate or reshape signals to extend transmission distance
  • BAssign IP addresses
  • CTranslate domain names
  • DEncrypt every application message
Report an error
Correct Answer: A. Regenerate or reshape signals to extend transmission distance
Explanation: A repeater operates at the physical layer and regenerates signals so they can travel farther.
Reference: Standard computer and networking fundamentals: networking devices
Question 1227
Computer & Networking BasicsNetworking Devices

NIC stands for?

  • ANetwork Interface Card
  • BNetwork Internet Code
  • CNode Integration Cable
  • DNumeric Interface Controller
Report an error
Correct Answer: A. Network Interface Card
Explanation: A Network Interface Card or controller provides a device with a network interface.
Reference: Standard computer and networking fundamentals: networking devices
Question 1229
Computer & Networking BasicsOSI Model

Which is the lowest layer of the OSI model?

  • APhysical layer
  • BTransport layer
  • CSession layer
  • DApplication layer
Report an error
Correct Answer: A. Physical layer
Explanation: The Physical layer is Layer 1 and deals with transmission of raw bits over the physical medium.
Reference: Standard computer and networking fundamentals: osi model
Question 1230
Computer & Networking BasicsOSI Model

Which OSI layer is responsible for logical addressing and routing?

  • ANetwork layer
  • BData Link layer
  • CPresentation layer
  • DPhysical layer
Report an error
Correct Answer: A. Network layer
Explanation: The Network layer provides logical addressing and routing functions between networks.
Reference: Standard computer and networking fundamentals: osi model
Question 1231
Computer & Networking BasicsOSI Model

Which OSI layer provides process-to-process transport services and commonly includes reliability and flow-control functions?

  • ATransport layer
  • BPhysical layer
  • CPresentation layer
  • DData Link layer
Report an error
Correct Answer: A. Transport layer
Explanation: The Transport layer provides end-to-end process communication; protocols such as TCP can add reliability and flow control.
Reference: Standard computer and networking fundamentals: osi model
Question 1232
Computer & Networking BasicsOSI Model

Which OSI layer is closest to end-user network applications?

  • AApplication layer
  • BPhysical layer
  • CData Link layer
  • DNetwork layer
Report an error
Correct Answer: A. Application layer
Explanation: Layer 7, the Application layer, provides network services directly used by application processes.
Reference: Standard computer and networking fundamentals: osi model
Question 1234
Computer & Networking BasicsTCP/IP Model

Which TCP/IP layer corresponds most closely to the OSI Network layer?

  • AApplication
  • BTransport
  • CInternet
  • DNetwork Access
Report an error
Correct Answer: C. Internet
Explanation: The TCP/IP Internet layer provides logical addressing and packet routing functions similar to the OSI Network layer.
Reference: Standard computer networking fundamentals: tcp/ip model
Question 1235
Computer & Networking BasicsIPv4 Addressing

An IPv4 address contains how many bits?

  • A16
  • B32
  • C64
  • D128
Report an error
Correct Answer: B. 32
Explanation: IPv4 addresses are 32 bits long, normally written as four decimal octets.
Reference: Standard computer networking fundamentals: ipv4 addressing
Question 1236
Computer & Networking BasicsIPv4 Addressing

Which of the following is a valid IPv4 address?

  • A192.168.1.25
  • B192.168.300.1
  • C10.10.10.256
  • D172.16.1
Report an error
Correct Answer: A. 192.168.1.25
Explanation: Each IPv4 octet must be in the range 0 through 255 and the usual dotted-decimal form contains four octets.
Reference: Standard computer networking fundamentals: ipv4 addressing
Question 1240
Computer & Networking BasicsSubnetting

For the network 192.168.10.0/24, the conventional broadcast address is?

  • A192.168.10.0
  • B192.168.10.1
  • C192.168.10.254
  • D192.168.10.255
Report an error
Correct Answer: D. 192.168.10.255
Explanation: With a /24 prefix, the final 8 bits are host bits; setting all of them to 1 gives 192.168.10.255.
Reference: Standard computer networking fundamentals: subnetting
Question 1241
Computer & Networking BasicsMAC Addressing

A MAC address is primarily associated with which OSI layer?

  • APhysical layer only
  • BData Link layer
  • CNetwork layer
  • DTransport layer
Report an error
Correct Answer: B. Data Link layer
Explanation: MAC addresses are used for Layer-2 frame delivery on technologies such as Ethernet.
Reference: Standard computer networking fundamentals: mac addressing
Question 1242
Computer & Networking BasicsMAC Addressing

A conventional Ethernet MAC address is how many bits long?

  • A32 bits
  • B48 bits
  • C64 bits
  • D128 bits
Report an error
Correct Answer: B. 48 bits
Explanation: Standard Ethernet MAC addresses are 48 bits, commonly written as six hexadecimal octets.
Reference: Standard computer networking fundamentals: mac addressing
Question 1243
Computer & Networking BasicsARP

ARP in IPv4 is used to determine a device’s?

  • AMAC address corresponding to a known local IPv4 address
  • BDomain name from an email address
  • CTCP port from a URL only
  • DSubnet mask from a password
Report an error
Correct Answer: A. MAC address corresponding to a known local IPv4 address
Explanation: ARP resolves an IPv4 address to the corresponding link-layer MAC address on the local network.
Reference: Standard computer networking fundamentals: arp
Question 1244
Computer & Networking BasicsDNS

DNS is primarily used to?

  • ATranslate domain names into IP addresses and provide related naming records
  • BAssign MAC addresses to switches
  • CRegenerate weak electrical signals
  • DEncrypt hard disks
Report an error
Correct Answer: A. Translate domain names into IP addresses and provide related naming records
Explanation: The Domain Name System maps human-readable names to IP addresses and stores other DNS resource records.
Reference: Standard computer networking fundamentals: dns
Question 1245
Computer & Networking BasicsDHCP

DHCP is commonly used to automatically provide hosts with?

  • AIP configuration parameters
  • BCPU instructions
  • CMAC addresses manufactured into NICs
  • DWeb page source code
Report an error
Correct Answer: A. IP configuration parameters
Explanation: DHCP can dynamically supply IP address, subnet mask, default gateway, DNS-server information and other network parameters.
Reference: Standard computer networking fundamentals: dhcp
Question 1249
Computer & Networking BasicsPorts

A transport-layer port number primarily identifies?

  • AAn application or process endpoint on a host
  • BA physical switch connector only
  • CA router's power supply
  • DA cable length
Report an error
Correct Answer: A. An application or process endpoint on a host
Explanation: TCP and UDP ports allow incoming traffic to be delivered to the appropriate application/process endpoint.
Reference: Standard computer networking fundamentals: ports
Question 1252
Computer & Networking BasicsApplication Protocols

SMTP is primarily used for?

  • ASending and relaying email
  • BResolving MAC addresses
  • CAssigning IP addresses
  • DTransferring Ethernet frames between switches only
Report an error
Correct Answer: A. Sending and relaying email
Explanation: SMTP is the standard application-layer protocol used to submit and relay email messages.
Reference: Standard computer networking fundamentals: application protocols
Question 1253
Computer & Networking BasicsApplication Protocols

FTP is designed primarily for?

  • AFile transfer
  • BDomain-name resolution
  • CAutomatic IP assignment
  • DClock synchronization only
Report an error
Correct Answer: A. File transfer
Explanation: FTP stands for File Transfer Protocol and is designed for transferring files between networked systems.
Reference: Standard computer networking fundamentals: application protocols
Question 1254
Computer & Networking BasicsNetwork Topologies

In a star topology, end devices are typically connected to?

  • AA central device such as a switch
  • BEvery other node with a dedicated cable
  • CA single unbroken bus only
  • DNo central connection point
Report an error
Correct Answer: A. A central device such as a switch
Explanation: A star topology connects each endpoint to a central hub or, more commonly today, an Ethernet switch.
Reference: Standard computer networking fundamentals: network topologies
Question 1255
Computer & Networking BasicsNetwork Topologies

In a bus topology, all nodes traditionally share?

  • AA common backbone communication medium
  • BA separate central switch port each
  • CA dedicated point-to-point link to every other node
  • DAn individual router to the Internet
Report an error
Correct Answer: A. A common backbone communication medium
Explanation: A classic bus network uses a shared backbone cable to which nodes are attached.
Reference: Standard computer networking fundamentals: network topologies
Question 1257
Computer & Networking BasicsEthernet Switching

A basic Ethernet switch reduces unnecessary frame delivery compared with a hub by learning?

  • ASource MAC addresses and associated ports
  • BApplication passwords
  • CCPU register values
  • DDNS zone files only
Report an error
Correct Answer: A. Source MAC addresses and associated ports
Explanation: A switch builds a MAC address table from source addresses and uses it to forward known unicast frames only toward the appropriate destination port.
Reference: Standard computer networking fundamentals: ethernet switching
Question 1258
Computer & Networking BasicsIP Addressing

Which of the following IPv4 address ranges is private?

  • A10.0.0.0/8
  • B8.0.0.0/8
  • C100.0.0.0/8
  • D200.0.0.0/8
Report an error
Correct Answer: A. 10.0.0.0/8
Explanation: 10.0.0.0/8 is one of the IPv4 address blocks reserved for private networks.
Reference: Standard computer networking fundamentals: ip addressing
Question 1259
Computer & Networking BasicsIP Addressing

Which address is within the private IPv4 block 172.16.0.0/12?

  • A172.15.1.1
  • B172.20.1.1
  • C172.32.1.1
  • D173.16.1.1
Report an error
Correct Answer: B. 172.20.1.1
Explanation: The private 172.16.0.0/12 range extends from 172.16.0.0 through 172.31.255.255.
Reference: Standard computer networking fundamentals: ip addressing
Question 1260
Computer & Networking BasicsIP Addressing

Which IPv4 range is reserved for loopback testing?

  • A127.0.0.0/8
  • B169.254.0.0/16
  • C224.0.0.0/4
  • D192.0.2.0/24
Report an error
Correct Answer: A. 127.0.0.0/8
Explanation: IPv4 addresses in 127.0.0.0/8 are reserved for loopback; 127.0.0.1 is commonly used as localhost.
Reference: Standard computer networking fundamentals: ip addressing
Question 1261
Computer & Networking BasicsIPv6

IPv6 addresses are how many bits long?

  • A32
  • B64
  • C128
  • D256
Report an error
Correct Answer: C. 128
Explanation: IPv6 uses 128-bit addresses, providing a much larger address space than IPv4.
Reference: Standard computer networking fundamentals: ipv6
Question 1262
Computer & Networking BasicsIPv6

Which notation is normally used to write IPv6 addresses?

  • AEight groups of hexadecimal values separated by colons
  • BFour decimal octets only
  • CSix binary groups separated by commas
  • DA single 32-bit decimal number
Report an error
Correct Answer: A. Eight groups of hexadecimal values separated by colons
Explanation: IPv6 addresses are normally represented as hexadecimal groups separated by colons, with permitted compression rules.
Reference: Standard computer networking fundamentals: ipv6
Question 1263
Computer & Networking BasicsIPv6

The IPv6 loopback address is?

  • A::1
  • B::
  • C127.0.0.1
  • DFF:FF:FF:FF:FF:FF
Report an error
Correct Answer: A. ::1
Explanation: IPv6 reserves ::1 as the loopback address.
Reference: Standard computer networking fundamentals: ipv6
Question 1264
Computer & Networking BasicsSubnetting

A /26 IPv4 subnet contains how many total addresses?

  • A32
  • B64
  • C128
  • D256
Report an error
Correct Answer: B. 64
Explanation: A /26 prefix leaves 6 host bits, so the subnet contains 2^6=64 total addresses.
Reference: Standard computer networking fundamentals: subnetting
Question 1266
Computer & Networking BasicsSubnetting

The subnet mask corresponding to /26 is?

  • A255.255.255.0
  • B255.255.255.128
  • C255.255.255.192
  • D255.255.255.224
Report an error
Correct Answer: C. 255.255.255.192
Explanation: A /26 mask has 26 leading 1 bits, giving 255.255.255.192.
Reference: Standard computer networking fundamentals: subnetting
Question 1267
Computer & Networking BasicsSubnetting

For the subnet 192.168.1.64/26, the broadcast address is?

  • A192.168.1.63
  • B192.168.1.64
  • C192.168.1.126
  • D192.168.1.127
Report an error
Correct Answer: D. 192.168.1.127
Explanation: A /26 block has 64 addresses. The block beginning at .64 ends at .127, which is its broadcast address.
Reference: Standard computer networking fundamentals: subnetting
Question 1268
Computer & Networking BasicsSubnetting

For 192.168.1.64/26, the conventional usable host range is?

  • A192.168.1.64 to 192.168.1.127
  • B192.168.1.65 to 192.168.1.126
  • C192.168.1.1 to 192.168.1.62
  • D192.168.1.128 to 192.168.1.191
Report an error
Correct Answer: B. 192.168.1.65 to 192.168.1.126
Explanation: The network address is .64 and broadcast is .127, leaving .65 through .126 for conventional host assignment.
Reference: Standard computer networking fundamentals: subnetting
Question 1269
Computer & Networking BasicsDefault Gateway

A host normally sends traffic to its default gateway when the destination is?

  • AOutside the host's local IP subnet
  • BIts own loopback address
  • CThe same host's RAM
  • DAlways on the same Ethernet port
Report an error
Correct Answer: A. Outside the host's local IP subnet
Explanation: The default gateway is the router used to reach destinations not directly on the local subnet.
Reference: Standard computer networking fundamentals: default gateway
Question 1270
Computer & Networking BasicsNAT

NAT is commonly used at an IPv4 network edge to?

  • ATranslate between private and public address information
  • BConvert MAC addresses into passwords
  • CIncrease CPU clock frequency
  • DReplace Ethernet frames with analog audio
Report an error
Correct Answer: A. Translate between private and public address information
Explanation: Network Address Translation commonly allows privately addressed hosts to communicate through public IPv4 addressing at the network boundary.
Reference: Standard computer networking fundamentals: nat
Question 1271
Computer & Networking BasicsNAT

PAT allows multiple private hosts to share a public IPv4 address primarily by distinguishing connections using?

  • ATransport-layer port numbers
  • BMonitor resolutions
  • CCable lengths
  • DCPU opcodes
Report an error
Correct Answer: A. Transport-layer port numbers
Explanation: Port Address Translation tracks flows using address and transport-port information so many internal connections can share one public address.
Reference: Standard computer networking fundamentals: nat
Question 1272
Computer & Networking BasicsICMP

ICMP is commonly used for?

  • ANetwork-layer error reporting and diagnostic messages
  • BWeb-page formatting
  • CEmail storage
  • DFile compression
Report an error
Correct Answer: A. Network-layer error reporting and diagnostic messages
Explanation: ICMP carries control, error and diagnostic information for IP networks.
Reference: Standard computer networking fundamentals: icmp
Question 1274
Computer & Networking BasicsNetwork Diagnostics

Traceroute or tracert primarily helps determine?

  • AThe sequence of Layer-3 hops toward a destination
  • BThe CPU cache size of a remote host
  • CThe physical length of every Ethernet cable
  • DA user's password
Report an error
Correct Answer: A. The sequence of Layer-3 hops toward a destination
Explanation: Traceroute exploits IP hop-limit/TTL behavior and returned control messages to reveal routers along a path.
Reference: Standard computer networking fundamentals: network diagnostics
Question 1275
Computer & Networking BasicsRouting

A router decreases an IPv4 packet’s TTL field when?

  • AForwarding the packet to the next hop
  • BReceiving a local keyboard input
  • CWriting data to RAM
  • DResolving a DNS name only
Report an error
Correct Answer: A. Forwarding the packet to the next hop
Explanation: Each router forwarding an IPv4 packet decrements TTL, helping prevent packets from circulating indefinitely.
Reference: Standard computer networking fundamentals: routing
Question 1276
Computer & Networking BasicsRouting

A routing table is used by a router to choose?

  • AA next hop or outgoing interface for a destination network
  • BA user's application password
  • CA switch's power rating
  • DThe CPU instruction set
Report an error
Correct Answer: A. A next hop or outgoing interface for a destination network
Explanation: Routers compare destination IP addresses with routing-table prefixes to determine how packets should be forwarded.
Reference: Standard computer networking fundamentals: routing
Question 1277
Computer & Networking BasicsRouting

When multiple routing-table entries match an IP destination, routers generally prefer the route with the?

  • ALongest matching prefix
  • BShortest matching prefix in every case
  • CLargest physical cable
  • DLowest destination IP address
Report an error
Correct Answer: A. Longest matching prefix
Explanation: Longest-prefix matching selects the most specific matching network route.
Reference: Standard computer networking fundamentals: routing
Question 1278
Computer & Networking BasicsVLAN

A VLAN is used to create separate logical?

  • ALayer-2 broadcast domains
  • BCPU cores
  • CInternet domain names
  • DPhysical-layer voltages
Report an error
Correct Answer: A. Layer-2 broadcast domains
Explanation: VLANs logically segment a switched Ethernet network into distinct Layer-2 broadcast domains.
Reference: Standard computer networking fundamentals: vlan
Question 1279
Computer & Networking BasicsEthernet Switching

On a switch, each individual switch port normally forms a separate?

  • ACollision domain
  • BIP broadcast domain regardless of VLAN
  • CAutonomous system
  • DDNS zone
Report an error
Correct Answer: A. Collision domain
Explanation: Modern switched Ethernet gives each port its own collision domain, unlike a shared hub segment.
Reference: Standard computer networking fundamentals: ethernet switching
Question 1280
Computer & Networking BasicsVLAN

Devices in different VLANs normally require what to communicate at the IP layer?

  • AInter-VLAN routing
  • BOnly a passive hub
  • CA crossover cable with no Layer-3 function
  • DNo networking device
Report an error
Correct Answer: A. Inter-VLAN routing
Explanation: Communication between separate VLAN IP networks requires a Layer-3 device or Layer-3 switching function.
Reference: Standard computer networking fundamentals: vlan
Question 1281
Computer & Networking BasicsWireless Networking

Wi-Fi LAN technologies are primarily standardized under?

  • AIEEE 802.11
  • BIEEE 802.3
  • CIEEE 802.15.4 only
  • DIEEE 754
Report an error
Correct Answer: A. IEEE 802.11
Explanation: The IEEE 802.11 family specifies wireless LAN technologies commonly known as Wi-Fi.
Reference: Standard computer networking fundamentals: wireless networking
Question 1282
Computer & Networking BasicsNetwork Security

A network firewall is primarily used to?

  • AControl network traffic according to security rules
  • BIncrease RAM capacity
  • CConvert binary to decimal
  • DGenerate an antenna carrier
Report an error
Correct Answer: A. Control network traffic according to security rules
Explanation: A firewall permits, blocks or otherwise controls network traffic according to configured security policy and inspection capabilities.
Reference: Standard computer networking fundamentals: network security
Question 1283
Computer & Networking BasicsAdvanced Subnetting

A /27 IPv4 subnet contains how many total addresses?

  • A16
  • B32
  • C64
  • D128
Report an error
Correct Answer: B. 32
Explanation: A /27 prefix leaves 5 host bits, so it contains 2^5=32 total IPv4 addresses.
Reference: Standard computer and networking fundamentals: advanced subnetting
Question 1285
Computer & Networking BasicsAdvanced Subnetting

The subnet mask corresponding to /27 is?

  • A255.255.255.128
  • B255.255.255.192
  • C255.255.255.224
  • D255.255.255.240
Report an error
Correct Answer: C. 255.255.255.224
Explanation: A /27 mask has 27 leading 1 bits, giving 255.255.255.224.
Reference: Standard computer and networking fundamentals: advanced subnetting
Question 1286
Computer & Networking BasicsAdvanced Subnetting

For the subnet 10.0.0.96/27, the broadcast address is?

  • A10.0.0.95
  • B10.0.0.96
  • C10.0.0.126
  • D10.0.0.127
Report an error
Correct Answer: D. 10.0.0.127
Explanation: A /27 has blocks of 32 addresses. The block starting at .96 ends at .127, its broadcast address.
Reference: Standard computer and networking fundamentals: advanced subnetting
Question 1291
Computer & Networking BasicsTCP

TCP connection establishment normally uses which sequence?

  • ASYN, SYN-ACK, ACK
  • BACK, FIN, RST
  • CSYN, FIN, ACK
  • DARP, SYN, DNS
Report an error
Correct Answer: A. SYN, SYN-ACK, ACK
Explanation: TCP normally establishes a connection using the three-way handshake SYN → SYN-ACK → ACK.
Reference: Standard computer and networking fundamentals: tcp
Question 1292
Computer & Networking BasicsTCP

In TCP, sequence numbers are mainly used to support?

  • AOrdered delivery and loss detection/retransmission
  • BDomain-name resolution
  • CMAC-address manufacturing
  • DPhysical signal regeneration
Report an error
Correct Answer: A. Ordered delivery and loss detection/retransmission
Explanation: TCP sequence numbers identify byte positions, enabling ordered reassembly and detection/recovery of missing data.
Reference: Standard computer and networking fundamentals: tcp
Question 1293
Computer & Networking BasicsTCP

A TCP acknowledgement primarily indicates?

  • AData successfully received up to an expected sequence point
  • BThe sender's MAC address has changed
  • CA DNS server is unavailable
  • DThe Ethernet cable is shielded
Report an error
Correct Answer: A. Data successfully received up to an expected sequence point
Explanation: TCP acknowledgements communicate reception progress and support reliable delivery.
Reference: Standard computer and networking fundamentals: tcp
Question 1294
Computer & Networking BasicsTCP

If a TCP segment is lost, reliability is commonly achieved by?

  • ARetransmission
  • BChanging the destination MAC permanently
  • CIncreasing the IPv4 address length
  • DDisabling sequence numbers
Report an error
Correct Answer: A. Retransmission
Explanation: TCP can retransmit data when acknowledgements or other loss-detection mechanisms indicate that data was not successfully delivered.
Reference: Standard computer and networking fundamentals: tcp
Question 1295
Computer & Networking BasicsEthernet Frames

Ethernet’s FCS field is primarily used for?

  • AError detection in the received frame
  • BIP address assignment
  • CEncryption of the entire frame
  • DRouting between autonomous systems
Report an error
Correct Answer: A. Error detection in the received frame
Explanation: The Frame Check Sequence contains a CRC value used to detect transmission errors in Ethernet frames.
Reference: Standard computer and networking fundamentals: ethernet frames
Question 1296
Computer & Networking BasicsEthernet Switching

A switch receives a unicast Ethernet frame whose destination MAC address is unknown in its MAC table. It normally?

  • AFloods the frame out appropriate ports in the same VLAN except the incoming port
  • BDrops every such frame immediately
  • CSends it only to the default gateway
  • DConverts it into an IP broadcast
Report an error
Correct Answer: A. Floods the frame out appropriate ports in the same VLAN except the incoming port
Explanation: Unknown unicast traffic is normally flooded within the relevant VLAN until the destination location is learned.
Reference: Standard computer and networking fundamentals: ethernet switching
Question 1297
Computer & Networking BasicsEthernet Frames

An Ethernet broadcast frame has which destination MAC address?

  • A00:00:00:00:00:00
  • BFF:FF:FF:FF:FF:FF
  • C01:00:00:00:00:00
  • D127:00:00:00:00:01
Report an error
Correct Answer: B. FF:FF:FF:FF:FF:FF
Explanation: All 48 destination bits are 1 for the Ethernet broadcast address, written FF:FF:FF:FF:FF:FF.
Reference: Standard computer and networking fundamentals: ethernet frames
Question 1298
Computer & Networking BasicsNetwork Segmentation

A Layer-2 switch normally does not forward a broadcast frame across?

  • AA router boundary
  • BPorts within the same VLAN
  • CThe local switch fabric
  • DAn Ethernet link in the same broadcast domain
Report an error
Correct Answer: A. A router boundary
Explanation: Routers separate Layer-2 broadcast domains and do not normally forward Ethernet broadcasts between IP networks.
Reference: Standard computer and networking fundamentals: network segmentation
Question 1299
Computer & Networking BasicsTroubleshooting

If a host can communicate with devices in its own subnet but cannot reach remote IP networks, a likely configuration to check first is the?

  • ADefault gateway
  • BMonitor refresh rate
  • CCPU cache
  • DKeyboard layout
Report an error
Correct Answer: A. Default gateway
Explanation: Local subnet traffic does not require a router, while remote-network traffic normally depends on a correctly configured and reachable default gateway.
Reference: Standard computer and networking fundamentals: troubleshooting