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Q&A- Computer Studies

Modulation refers to the process of converting a digital signal to analog signal at the transmission end while demodulation is to converting analog signal to digital signal at the receiving end

  • switches can send and receive data simultaneously - they are full duplex
  • a hub is half duplex- only one host can communicate at a time.
  • a hub broadcast signals to all computers connected in a network while a switch directs data to its intended destination
  • connects different networks
  • transfer data packets from source to destination
  • allow hosts on different networks to communicate
  •  It does not have declaration part
  • It does not  have control structures
  • It refers to a system software that provides a platform for installation and execution of an application software and also manages the computer hardware
  • Commandline/ Character interface Operating systems
  •  Menu Driven Operating Systems
  •  Graphical User Interface Operating Systems
  • Object code refers to a program in machine language while source code to a program in a high level language that must be translated to object code for it to be machine readable
  • Distributed data processing is where computers located in physically separate location transmit data after processing to a server computer that updates the master file. Time-sharing on the other hand is where various terminals transmit data to be processed by a central computer's CPU. Each terminal's tasks are allocated a time slice of the CPU
The process of developing computer programs to solve a particular problem
A computer system refers to computer components that collectively function as a single unit to achieve a desired goal
  • compact disks
  • DVDs
  • Blue Ray
  • Repeaters : amplify data signal thereby extending the physical coverage of a network. It can connect two LANs locally.
  • Bridges: connect similar types of networks e.g a token ring to another token ring
  • Routers: link networks of different types
  • Gateway: allows computers in a network to connect regardless of their topology
  • Open source : refers to software provided freely with its source code. The user can modify and redistribute the software.
  • Freeware: these are software that can be downloaded for free and distributed but the source code is hidden and cannot be altered.
  • shareware: are software that are available for free within a given trial period after which it must be bought.
  • proprietary: software made for commercial purposes. The source code is hidden and it can only be used after paying for licence.

 

  • It refers to a computer that controls other computers in a network and monitors user's access to the shared resources.
  • A computer is an electronic device that operates (works) under the control of programs stored in its own memory unit
  • An electronic device that accepts data, as input and transforms it under the influence of a set of special instructions called programs, to produce the desired output (referred to as information)
A set of connected computers and other devices which share resources such as software, internet connection,printers etc

Sequence:Sequential execution of a program one line after another

Selection: Involve the a decision between two or more options e.g  if...then...else

Loops/Repetitions:use for looping i.e a line of code can be made to execute a given number times before terminating.

  • Optical scanner is used read data by use a beam of light while a magnetic ink scanner is used to read data encoded/written using magnetic ink by magnetising the ink characters and translating them
  • Optical Mark Recognition
  • Optical Character Recognition
  • Magnetic Ink Character recognition

 

a)Spreadsheets                                                                                                                               (2mks)

  • Microsoft Excel
  • Lotus 1-2-3
  • Google Sheets
  • OpenOffice Calc

                                           Any 2 @ 1mk

 

b) Word processors                                                                                                                          (2mks)

  • Microsoft Word
  • Wordpad
  • Corel WordPerfect
  • Lotus Word Pro

 

                                         Any 2 @ 1mk