Which of the following devices performs signal conversion?
- A.Modulator
- B.Mouse
- C.Plotter
- D.Keyboard
Correct answer
Explanation
The correct answer is A, Modulator. 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. The reverse device, a demodulator, recovers the bits at the far end, and the two together make the modem, whose very name is short for modulator-demodulator. Option B is wrong because a mouse is a pointing input device; it sends position and click data to the computer but does not convert one form of signal into another. Option C is wrong because a plotter is an output device that draws large line diagrams, maps and engineering drawings with pens on paper. Option D is wrong because a keyboard is an input device that turns keystrokes into character codes for the processor, which is coding rather than signal conversion between digital and analog forms.
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 →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.
Read the full explanation →A router works at which layer of the OSI reference model?
- A.Physical layer
- B.Data Link layer
- C.Network layer
- D.Transport layer
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A router joins two or more different networks and decides, for every packet, which outgoing line will carry it towards its destination.
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