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BHEL MCQs

Practice BHEL-oriented Electronics & Telecommunication Engineering MCQs with answers and explanations for technical exam preparation. Questions are arranged in pages of up to 100.

Question 1201

Computer & Networking BasicsComputer Memory

Which type of memory normally retains its contents when power is removed?

AROM
BDRAM
CSRAM used as volatile cache
DCPU register

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Correct Answer: A. ROM

Explanation: ROM is non-volatile memory and retains stored information without continuous power.

Reference: Standard computer and networking fundamentals: computer memory

Question 1202

Computer & Networking BasicsComputer Memory

Which memory is normally the fastest among these?

ACPU register
BMain RAM
CSSD
DHard disk drive

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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 1203

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

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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 1204

Computer & Networking BasicsData Representation

One byte contains how many bits?

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Correct Answer: B. 8

Explanation: A byte is conventionally defined as 8 bits.

Reference: Standard computer and networking fundamentals: data representation

Question 1205

Computer & Networking BasicsData Representation

A binary digit can have which values?

A0 or 1
B0 to 7
C0 to 9
DA to F only

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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 1206

Computer & Networking BasicsData Representation

The binary number 1010 is equal to which decimal number?

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Correct Answer: B. 10

Explanation: 1010₂=1×8+0×4+1×2+0×1=10.

Reference: Standard computer and networking fundamentals: data representation

Question 1207

Computer & Networking BasicsData Representation

The hexadecimal number FF is equal to which decimal number?

A15
B127
C255
D256

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Correct Answer: C. 255

Explanation: FF₁₆=15×16+15=255.

Reference: Standard computer and networking fundamentals: data representation

Question 1208

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

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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 1209

Computer & Networking BasicsOperating Systems

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

ALinux
BHTML
CHTTP
DEthernet cable

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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 1210

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

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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 1211

Computer & Networking BasicsNetwork Types

LAN stands for?

ALocal Area Network
BLong Access Node
CLogical Analog Network
DLarge Antenna Network

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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 1212

Computer & Networking BasicsNetwork Types

WAN stands for?

AWide Area Network
BWireless Access Number
CWired Analog Node
DWeb Application Name

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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 1213

Computer & Networking BasicsNetworking Devices

Which device commonly connects different IP networks and forwards packets between them?

ARouter
BPassive hub only
CKeyboard
DRepeater only

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Correct Answer: A. Router

Explanation: A router examines network-layer addressing and forwards packets between IP networks.

Reference: Standard computer and networking fundamentals: networking devices

Question 1214

Computer & Networking BasicsNetworking Devices

NIC stands for?

ANetwork Interface Card
BNetwork Internet Code
CNode Integration Cable
DNumeric Interface Controller

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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 1215

Computer & Networking BasicsOSI Model

In the OSI reference model, how many layers are there?

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Correct Answer: C. 7

Explanation: The OSI reference model contains seven layers.

Reference: Standard computer and networking fundamentals: osi model

Question 1216

Computer & Networking BasicsOSI Model

Which is the lowest layer of the OSI model?

APhysical layer
BTransport layer
CSession layer
DApplication layer

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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 1217

Computer & Networking BasicsOSI Model

Which OSI layer is responsible for logical addressing and routing?

ANetwork layer
BData Link layer
CPresentation layer
DPhysical layer

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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 1218

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

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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 1219

Computer & Networking BasicsOSI Model

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

AApplication layer
BPhysical layer
CData Link layer
DNetwork layer

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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 1220

Computer & Networking BasicsMAC Addressing

A MAC address is primarily associated with which OSI layer?

APhysical layer only
BData Link layer
CNetwork layer
DTransport layer

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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 1221

Computer & Networking BasicsMAC Addressing

A conventional Ethernet MAC address is how many bits long?

A32 bits
B48 bits
C64 bits
D128 bits

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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 1222

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

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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 1223

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

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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 1224

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

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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 1225

Computer & Networking BasicsTCP & UDP

Which transport-layer protocol is connection-oriented and provides reliable ordered byte-stream delivery?

AUDP
BTCP
CIP
DARP

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Correct Answer: B. TCP

Explanation: TCP establishes a connection and provides sequencing, acknowledgements and retransmission for reliable ordered delivery.

Reference: Standard computer networking fundamentals: tcp & udp

Question 1226

Computer & Networking BasicsTCP/IP Model

The TCP/IP model is commonly represented using how many layers in its traditional form?

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Correct Answer: B. 4

Explanation: The traditional TCP/IP model has four layers: Application, Transport, Internet, and Network Access.

Reference: Standard computer networking fundamentals: tcp/ip model

Question 1227

Computer & Networking BasicsTCP/IP Model

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

AApplication
BTransport
CInternet
DNetwork Access

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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 1228

Computer & Networking BasicsIPv4 Addressing

An IPv4 address contains how many bits?

A16
B32
C64
D128

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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 1229

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

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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 1230

Computer & Networking BasicsSubnetting

The subnet mask 255.255.255.0 is equivalent to which CIDR prefix?

A/8
B/16
C/24
D/32

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Correct Answer: C. /24

Explanation: 255.255.255.0 contains 24 leading 1 bits, so its CIDR notation is /24.

Reference: Standard computer networking fundamentals: subnetting

Question 1231

Computer & Networking BasicsSubnetting

How many total IPv4 addresses are contained in a /24 subnet?

A64
B128
C256
D512

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Correct Answer: C. 256

Explanation: A /24 leaves 8 host bits, giving 2^8=256 total addresses.

Reference: Standard computer networking fundamentals: subnetting

Question 1232

Computer & Networking BasicsSubnetting

In a conventional IPv4 /24 subnet, how many addresses are normally available for assignment to hosts?

A254
B255
C256
D252

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Correct Answer: A. 254

Explanation: Traditionally one address identifies the network and one is the broadcast address, leaving 256-2=254 usable host addresses.

Reference: Standard computer networking fundamentals: subnetting

Question 1233

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

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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 1234

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

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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 1235

Computer & Networking BasicsTCP & UDP

Which transport-layer protocol is connectionless and has relatively low protocol overhead?

ATCP
BUDP
CHTTP
DARP

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Correct Answer: B. UDP

Explanation: UDP sends independent datagrams without connection establishment or built-in retransmission and ordering mechanisms.

Reference: Standard computer networking fundamentals: tcp & udp

Question 1236

Computer & Networking BasicsTCP & UDP

Which protocol is generally preferred when reliable file delivery is more important than minimum transport latency?

ATCP
BUDP only
CARP
DICMP only

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Correct Answer: A. TCP

Explanation: TCP's acknowledgement, sequencing and retransmission mechanisms make it appropriate when reliable delivery is required.

Reference: Standard computer networking fundamentals: tcp & udp

Question 1237

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

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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 1238

Computer & Networking BasicsApplication Protocols

The default port traditionally associated with HTTP is?

A21
B25
C80
D443

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Correct Answer: C. 80

Explanation: HTTP conventionally uses TCP port 80 by default.

Reference: Standard computer networking fundamentals: application protocols

Question 1239

Computer & Networking BasicsApplication Protocols

The default port traditionally associated with HTTPS is?

A53
B110
C443
D8080

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Correct Answer: C. 443

Explanation: HTTPS conventionally uses TCP port 443.

Reference: Standard computer networking fundamentals: application protocols

Question 1240

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

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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 1241

Computer & Networking BasicsApplication Protocols

FTP is designed primarily for?

AFile transfer
BDomain-name resolution
CAutomatic IP assignment
DClock synchronization only

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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 1242

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

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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 1243

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

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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 1244

Computer & Networking BasicsEthernet

Ethernet is standardized primarily by which IEEE family?

AIEEE 802.3
BIEEE 802.11
CIEEE 754
DIEEE 488

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Correct Answer: A. IEEE 802.3

Explanation: IEEE 802.3 specifies Ethernet technologies.

Reference: Standard computer networking fundamentals: ethernet

Question 1245

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

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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 1246

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

Show AnswerHide Answer 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 1247

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

Show AnswerHide Answer 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 1248

Computer & Networking BasicsIPv6

IPv6 addresses are how many bits long?

A32
B64
C128
D256

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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 1249

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

Show AnswerHide Answer 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 1250

Computer & Networking BasicsNetwork Diagnostics

The ping utility commonly uses which protocol to test IP reachability?

AICMP
BFTP
CSMTP
DARP only across the entire Internet

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Correct Answer: A. ICMP

Explanation: Ping normally sends ICMP Echo Request messages and listens for Echo Reply messages.

Reference: Standard computer networking fundamentals: network diagnostics

Question 1251

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

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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 1252

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

Show AnswerHide Answer 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 1253

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

Show AnswerHide Answer 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 1254

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

Show AnswerHide Answer 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 1255

Computer & Networking BasicsVLAN

A VLAN is used to create separate logical?

ALayer-2 broadcast domains
BCPU cores
CInternet domain names
DPhysical-layer voltages

Show AnswerHide Answer 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 1256

Computer & Networking BasicsIPv6

The IPv6 loopback address is?

A::1
B::
C127.0.0.1
DFF:FF:FF:FF:FF:FF

Show AnswerHide Answer Report an error

Correct Answer: A. ::1

Explanation: IPv6 reserves ::1 as the loopback address.

Reference: Standard computer networking fundamentals: ipv6

Question 1257

Computer & Networking BasicsSubnetting

A /26 IPv4 subnet contains how many total addresses?

A32
B64
C128
D256

Show AnswerHide Answer 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 1258

Computer & Networking BasicsSubnetting

In conventional IPv4 subnetting, how many usable host addresses are available in a /26 subnet?

A30
B62
C64
D126

Show AnswerHide Answer Report an error

Correct Answer: B. 62

Explanation: A /26 contains 64 total addresses; excluding network and broadcast addresses leaves 62 conventional usable host addresses.

Reference: Standard computer networking fundamentals: subnetting

Question 1259

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

Show AnswerHide Answer 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 1260

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

Show AnswerHide Answer 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 1261

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

Show AnswerHide Answer 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 1262

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

Show AnswerHide Answer 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 1263

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

Show AnswerHide Answer 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 1264

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

Show AnswerHide Answer 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 1265

Computer & Networking BasicsICMP

ICMP is commonly used for?

ANetwork-layer error reporting and diagnostic messages
BWeb-page formatting
CEmail storage
DFile compression

Show AnswerHide Answer 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 1266

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

Show AnswerHide Answer 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 1267

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

Show AnswerHide Answer 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 1268

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

Show AnswerHide Answer 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 1269

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

Show AnswerHide Answer 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 1270

Computer & Networking BasicsAdvanced Subnetting

A /27 IPv4 subnet contains how many total addresses?

A16
B32
C64
D128

Show AnswerHide Answer 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 1271

Computer & Networking BasicsAdvanced Subnetting

In conventional IPv4 subnetting, a /27 subnet provides how many usable host addresses?

Show AnswerHide Answer Report an error

Correct Answer: B. 30

Explanation: A /27 contains 32 total addresses; excluding network and broadcast addresses leaves 30 conventional usable host addresses.

Reference: Standard computer and networking fundamentals: advanced subnetting

Question 1272

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

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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 1273

Computer & Networking BasicsData Rate

Ignoring protocol overhead, transferring an 80 Mbit file over an ideal 20 Mbps link requires approximately?

A2 s
B4 s
C8 s
D16 s

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Correct Answer: B. 4 s

Explanation: Time=data/rate=80 Mbit/20 Mbit/s=4 seconds.

Reference: Standard computer and networking fundamentals: data rate

Question 1274

Computer & Networking BasicsData Rate

A 10 MB file contains approximately how many megabits when using 8 bits per byte and decimal MB for this calculation?

A10 Mbit
B20 Mbit
C40 Mbit
D80 Mbit

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Correct Answer: D. 80 Mbit

Explanation: 10 MB×8 bits/byte=80 megabits under the stated decimal-unit assumption.

Reference: Standard computer and networking fundamentals: data rate

Question 1275

Computer & Networking BasicsTCP

TCP connection establishment normally uses which sequence?

ASYN, SYN-ACK, ACK
BACK, FIN, RST
CSYN, FIN, ACK
DARP, SYN, DNS

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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 1276

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

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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 1277

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

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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 1278

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

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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 1279

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

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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 1280

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

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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 1281

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

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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 1282

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

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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 1283

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

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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

Question 1284

Computer & Networking BasicsTroubleshooting

If users can reach a web server by IP address but not by its domain name, which service should be checked first?

ADNS
BDHCP lease duration only
CEthernet FCS
DCPU scheduler

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Correct Answer: A. DNS

Explanation: Successful IP connectivity with failed name-based access commonly indicates a DNS resolution problem.

Reference: Standard computer and networking fundamentals: troubleshooting

Question 1285

Computer & Networking BasicsDHCP

If a DHCP client cannot obtain a lease, which configuration may it fail to receive automatically?

AIP address and related network parameters
BFactory-programmed MAC address
CCPU instruction set
DHard-disk sector size

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Correct Answer: A. IP address and related network parameters

Explanation: DHCP supplies dynamic IP configuration such as address, mask, gateway and DNS-server information.

Reference: Standard computer and networking fundamentals: dhcp

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

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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 1287

Computer & Networking BasicsAdvanced Subnetting

A network requires at least 50 conventional usable IPv4 host addresses. Which is the smallest suitable prefix among these?

A/25
B/26
C/27
D/28

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Correct Answer: B. /26

Explanation: A /26 provides 64 total and 62 conventional usable addresses; /27 provides only 30 usable addresses.

Reference: Standard computer and networking fundamentals: advanced subnetting

Question 1288

Computer & Networking BasicsData Rate

A 100 Mbps link can theoretically transmit how many bits in 2 seconds, ignoring all overhead?

A50 million bits
B100 million bits
C200 million bits
D800 million bits

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Correct Answer: C. 200 million bits

Explanation: 100 megabits per second for 2 seconds gives 200 megabits, or about 200 million bits.

Reference: Standard computer and networking fundamentals: data rate

Question 1289

Computer & Networking BasicsCybersecurity Fundamentals

Which security property aims to keep systems and data accessible to authorized users when required?

AAvailability
BCompression
CModulation
DAddress resolution

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Correct Answer: A. Availability

Explanation: Availability is the security objective of maintaining timely and reliable access to systems and information.

Reference: Standard computer and networking fundamentals: cybersecurity fundamentals

Question 1290

Computer & Networking BasicsCybersecurity Fundamentals

Phishing is an attack that commonly attempts to?

ATrick users into revealing credentials or other sensitive information
BIncrease Ethernet bandwidth
CImprove routing convergence
DRepair corrupted files automatically

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Correct Answer: A. Trick users into revealing credentials or other sensitive information

Explanation: Phishing uses deceptive messages or sites to manipulate users into disclosing information or taking unsafe actions.

Reference: Standard computer and networking fundamentals: cybersecurity fundamentals

Question 1291

Computer & Networking BasicsCybersecurity Fundamentals

Using a unique strong password together with multi-factor authentication primarily improves account security by?

ARequiring more than one form of evidence and reducing reliance on a password alone
BMaking IP addresses unnecessary
CEliminating all malware permanently
DIncreasing physical cable bandwidth

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Correct Answer: A. Requiring more than one form of evidence and reducing reliance on a password alone

Explanation: MFA adds an independent authentication factor, so possession of a password alone is less likely to be sufficient for account access.

Reference: Standard computer and networking fundamentals: cybersecurity fundamentals

Question 1292

Computer & Networking BasicsDHCP

A DHCP relay is useful when the DHCP server and client are?

AOn different IP subnets
BInside the same CPU register
CConnected by no network
DUsing only loopback addresses

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Correct Answer: A. On different IP subnets

Explanation: DHCP discovery begins with local broadcasts, so a relay can forward DHCP messages between client and server across router boundaries.

Reference: Standard computer and networking fundamentals: dhcp

Question 1293

Computer & Networking BasicsCybersecurity Fundamentals

Which security property means information should be accessible only to authorized entities?

AConfidentiality
BAvailability
CRedundancy
DBroadcasting

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Correct Answer: A. Confidentiality

Explanation: Confidentiality protects information from unauthorized disclosure.

Reference: Standard computer and networking fundamentals: cybersecurity fundamentals

Question 1294

Computer & Networking BasicsCybersecurity Fundamentals

Which security property aims to prevent unauthorized alteration of data?

AIntegrity
BLatency
CThroughput
DFragmentation

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Correct Answer: A. Integrity

Explanation: Integrity concerns the correctness and trustworthiness of data and protection against unauthorized modification.

Reference: Standard computer and networking fundamentals: cybersecurity fundamentals

Question 1295

Digital ElectronicsLogic Families

A logic output can sink a maximum LOW-state current of 16 mA. Each connected input requires 1.6 mA when LOW. Ignoring other limits, the LOW-state fan-out is?

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Correct Answer: C. 10

Explanation: Fan-out based on LOW-state current is IOL(max)/IIL = 16/1.6 = 10 loads.

Reference: Standard digital electronics: fan-out calculation

Question 1296

Digital ElectronicsBoolean Minimization

A combinational circuit has F(A,B,C)=Σm(1,3,5,7). Which simplified expression represents F?

AA
BB
CC
DA + B

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Correct Answer: C. C

Explanation: Minterms 1, 3, 5, and 7 are exactly the input combinations for which C=1, independent of A and B. Therefore F=C.

Reference: Standard digital electronics: Boolean minimization

Question 1297

Digital ElectronicsLogic Hazards

In a static-1 hazard, the output of a combinational circuit may momentarily do what even though it should remain at logic 1?

ARemain permanently LOW
BDrop briefly to logic 0
COscillate indefinitely
DBecome high-impedance

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Correct Answer: B. Drop briefly to logic 0

Explanation: A static-1 hazard is an unwanted 1→0→1 glitch caused by unequal propagation delays along different logic paths.

Reference: Standard digital electronics: static hazards

Question 1298

Digital ElectronicsLogic Hazards

For the SOP function F = AB + A̅C, which consensus term can be added to eliminate the potential static-1 hazard between the two product terms?

AAC
BBC
CA̅B
DABC

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Correct Answer: B. BC

Explanation: By the consensus theorem, the consensus of AB and A̅C is BC. Adding BC provides overlapping coverage and can eliminate the static-1 hazard.

Reference: Standard digital electronics: consensus theorem and hazards

Question 1299

Digital ElectronicsArithmetic Circuits

A 4-bit binary adder uses identical ripple-carry full-adder stages. If each stage requires 12 ns for its carry output to become valid after carry-in changes, approximately what is the worst-case carry propagation time through all four stages?

A12 ns
B24 ns
C36 ns
D48 ns

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Correct Answer: D. 48 ns

Explanation: In a ripple-carry adder, a carry may propagate serially through all four stages. The approximate worst-case carry delay is 4 × 12 ns = 48 ns.

Reference: Standard digital electronics: ripple-carry adder delay

Question 1300

Digital ElectronicsArithmetic Circuits

The principal purpose of carry look-ahead logic in a binary adder is to?

AReduce carry propagation delay
BConvert binary to Gray code
CStore the carry permanently
DReduce the number of sum bits

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Correct Answer: A. Reduce carry propagation delay

Explanation: Carry look-ahead forms carry signals from generate and propagate terms in parallel, reducing the delay associated with a ripple-carry chain.

Reference: Standard digital electronics: carry look-ahead