Computer Networks Quiz For Class 12

✅ Answer: (b) Advanced Research Projects Agency Network

ARPANET stands for Advanced Research Projects Agency Network — widely regarded as the precursor to the modern Internet, developed in the late 1960s.

✅ Answer: (c) DARPA (Defense Advanced Research Projects Agency)

DARPA, a research arm of the U.S. Department of Defense, funded and developed ARPANET — hence the name.

✅ Answer: (b) Military research and communication

ARPANET was originally built for military research and communication purposes, allowing researchers at different institutions to share computing resources reliably.

✅ Answer: (b) Academic and research networking

NSFNET was built to connect universities and research institutions, extending networking beyond ARPANET’s military roots into the academic and research world — a major stepping stone toward the modern Internet.

✅ Answer: (c) Creation of the World Wide Web (WWW)

The creation of the World Wide Web (by Tim Berners-Lee in 1989-91) is the development most credited with transforming a research network into the accessible, browsable Internet the general public uses today.

✅ Answer: (b) The process of transferring data between devices through a communication medium

Communication, in this context, is simply the process of transferring data between devices — over any medium (wired or wireless), not necessarily radio waves.

✅ Answer: (d) Sender, Receiver, Message, Communication Medium, and Protocol

A complete data communication system needs all five: a Sender (creates the message), a Receiver (gets it), the Message itself, a Communication Medium (the physical/wireless path it travels), and a Protocol (the rules both ends agree to follow). (This question is corrected/expanded from a version that only listed three components — Transmitter, Receiver, Data — leaving out the medium and protocol, even though the topic’s own syllabus explicitly names all five.)

✅ Answer: (b) A set of rules that governs how data is formatted and exchanged between devices

A protocol is an agreed-upon set of rules that both the sender and receiver follow, covering things like data formatting, timing, sequencing, and error handling — e.g. HTTP, TCP/IP.

✅ Answer: (b) To assess the maximum capacity of data the medium can carry in a given time

Bandwidth measures a channel’s maximum theoretical capacity to carry data over a given time (commonly expressed in bits per second) — it tells you the upper limit the medium can support.

✅ Answer: (b) Bandwidth represents the maximum theoretical capacity of a channel, while data transfer rate is the actual speed of data achieved in practice

Bandwidth is the channel’s theoretical maximum capacity. Data transfer rate is the actual rate data moves in real conditions, which is usually somewhat lower than the bandwidth due to overhead, interference, or congestion. (This question is corrected from a version whose marked answer had the relationship backwards — describing bandwidth as “a measure of speed” and data transfer rate as “a measure of capacity”, the reverse of how these terms are actually defined.)

✅ Answer: (b) To identify and locate a specific device on a network

An IP address uniquely identifies a device’s location on a network, so data knows exactly where to be sent and where it came from — similar to a postal address.

✅ Answer: (b) Breaking data into small packets, each routed independently across the network

Packet switching breaks a message into smaller packets, each sent independently (potentially via different routes) and reassembled at the destination — this is how the modern Internet moves data.

✅ Answer: (d) Packet switching breaks data into packets that share network resources rather than needing one dedicated path

Packet switching doesn’t reserve a dedicated path — packets share available network resources and can take different routes. (Careful: the dedicated-path property actually describes circuit switching, not packet switching — a commonly confused, reversed-logic trap in this topic.)

✅ Answer: (a) Bandwidth IS essentially the measure of a channel’s maximum data-carrying capacity

Bandwidth and capacity are essentially the same idea, expressed in bits per second — the higher the bandwidth, the more data the channel can theoretically carry per second.

✅ Answer: (b) To forward and route data between different networks (e.g. connecting a LAN to the Internet)

A router connects different networks to each other — most commonly, your home LAN to your ISP’s wider network/the Internet — and decides the best path for data to travel between them. (A switch, by contrast, connects devices within the same local network.)

✅ Answer: (a) Network Interface Card — the hardware component that lets a device physically connect to a network

A NIC (Network Interface Card) is the hardware — built-in or a separate card — that allows a computer to physically connect to a network and send/receive data over it.

✅ Answer: (b) Simplex is one-way only; half-duplex is two-way but not simultaneous; full-duplex is two-way simultaneous

Simplex: data flows in only one direction (e.g. a keyboard to a computer). Half-duplex: data flows both ways, but only one direction at a time (e.g. a walkie-talkie). Full-duplex: data flows both ways simultaneously (e.g. a telephone call).

✅ Answer: (a) Guided media use a physical path like cables; unguided media transmit signals through the air without any physical conductor

Guided media (twisted pair, coaxial cable, fiber optic) carry signals along a physical path. Unguided media (radio waves, microwaves, infrared/Wi-Fi, Bluetooth) transmit signals through the air, with no physical conductor connecting the sender and receiver.

✅ Answer: (b) The Internet is the global network of interconnected computers/infrastructure; the WWW is a service (a system of linked web pages) that runs ON TOP of the Internet

The Internet is the vast physical/logical network infrastructure connecting computers worldwide. The World Wide Web is just one of the many services that use this infrastructure — specifically, the system of linked hypertext web pages accessed via browsers. Email, file transfer, and video calls also run over the Internet, but aren’t part of the Web itself.

✅ Answer: (a) IPv4 uses a 32-bit address; IPv6 uses a much larger 128-bit address, allowing vastly more unique addresses

IPv4 addresses are 32 bits long (e.g. 192.168.1.1), offering about 4.3 billion unique addresses — which the world has essentially run out of. IPv6 uses 128-bit addresses, providing an astronomically larger address space to accommodate the growing number of internet-connected devices.