A MAC address is how many bits long?
- A.16 bits
- B.32 bits
- C.48 bits
- D.128 bits
Correct answer
Explanation
The correct answer is C, 48 bits. The Media Access Control address is the permanent physical address written into the network interface card by its maker, and it is 48 bits long, shown to users as twelve hexadecimal digits in six pairs such as 00:1A:2B:3C:4D:5E. The first half identifies the manufacturer and the second half the particular card, so no two cards in the world should carry the same value. Option A is wrong because 16 bits is the width of a port number, which identifies an application and not a machine. Option B is wrong because 32 bits is the length of an IPv4 address, a logical address that changes when the machine moves to another network. Option D is wrong because 128 bits is the length of an IPv6 address, adopted because the supply of 32-bit IPv4 addresses was running out.
Read the full article: Computer Networks: Topologies, Devices and OSI Layers
Practice Questions
View allIn terms of computers, the set of ways in which an adversary can enter a system and can potentially cause damage is called:
- A.Attack Surface
- B.Attack Signature
- C.Attack Pattern
- D.Attack Path
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The attack surface of a system is the total collection of every point at which an unauthorised person could try to enter it or pull data out of it: open ports, running services, user accounts, login pages, removable drives and even the employees who can be tricked.
Read the full explanation →Which of the following devices performs signal conversion?
- A.Modulator
- B.Mouse
- C.Plotter
- D.Keyboard
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A modulator changes the form of a signal: it loads the digital bits produced by a computer onto an analog carrier wave so that they can travel over a telephone line, a cable or a radio link.
Read the full explanation →What is the full form of GPRS in mobile computing?
- A.General Packet Radio Service
- B.General Packet Route service
- C.General Package Radio Service
- D.General Packet Radiation Service
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GPRS was added to the 2G cellular system so that the same radio channel could carry data in packets instead of holding a circuit open the way a voice call does.
Read the full explanation →In which network topology is every node connected to a single central device?
- A.Bus topology
- B.Ring topology
- C.Star topology
- D.Mesh topology
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In a star network every computer has its own cable running to a central hub or switch, so the shape resembles the spokes of a wheel.
Read the full explanation →How many cables are needed to connect 6 computers in a fully connected mesh topology?
- A.12
- B.15
- C.18
- D.30
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In a full mesh every node is joined directly to every other node, so the number of links equals the number of pairs that can be formed from the nodes, given by the formula n(n-1)/2.
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