Computer Internet Questions and Answers

Answer: B

Correct answer: 2 and 3

A bridge divides a network into separate collision domains, so stations on either side no longer contend with each other, which gives each segment its own share of the bandwidth. A bridge forwards broadcasts, so it does not divide the broadcast domain - that requires a router.

Answer: C

Correct answer: Protocol

A protocol is the agreed set of rules governing how data is formatted, addressed, transmitted and acknowledged, so that two machines that have never met can understand each other.

Answer: C

Correct answer: Multiplexing

Multiplexing divides one physical link into several logical channels - by frequency, by time slot or by code - so that a costly medium carries many conversations at once instead of one.

Answer: D

Correct answer: Bandwidth

Bandwidth is the range of frequencies a medium can carry, and it is because that range limits how fast data can be sent that the word came to be used for data rate as well.

Answer: C

Correct answer: Coaxial Cable

Guided media confine the signal to a physical path: twisted pair, coaxial cable and optical fibre. Unguided media - radio, microwave, infrared - let it travel through free space.

Answer: D

Correct answer: Redundancy

Error detection works by sending more bits than the message strictly needs, so that a corrupted message no longer fits the pattern. That surplus is called redundancy, and parity bits, checksums and CRCs are all ways of adding it.

Answer: D

Correct answer: 1, 3 and 4

Flow control keeps a fast sender from overwhelming a slow receiver, and the three methods are buffering the excess, windowing to limit how much may be outstanding, and signalling congestion avoidance when the receiver falls behind. Cut-through is a switching method, describing when a frame is forwarded, not a means of flow control.

Answer: D

Correct answer: It requires a second, independent proof of identity besides the password

Two-factor authentication requires a second proof of identity in addition to the password, so that a stolen password alone is not enough to gain access. The factors are conventionally grouped as something you know - a password or PIN; something you have - a phone, a hardware key, a one-time code; and something you are - a fingerprint, a face. Genuine two-factor authentication uses two different groups; two passwords are not two factors. It is the single most effective defence against phishing and credential theft, because an attacker who obtains a password by any means still cannot log in. The methods differ in strength. SMS codes are the weakest, being vulnerable to SIM-swapping; an authenticator application generating time-based codes is better; and a hardware security key is the strongest, since it verifies the site’s identity too and so cannot be phished at all.

Answer: C

Correct answer: Packet

Data to be sent is divided into packets, each carrying the message content together with the addressing and control information the network needs. A header and trailer are parts of a packet rather than the whole.

Answer: C

Correct answer: star

A hub sits at the centre with a separate cable to each node, which is exactly the star arrangement. Logically it still behaves as a shared bus, since it repeats every signal to every port.