Ch- 2 COMPUTER VIRUS & NETWORKS

I.FILL IN THE BLANKS
1.Computer 2.Boot Record infector , System Virus , or Boot Virus 3.File infectors 4.Node 5. Back up 6. Digital 7. .gif 8. High resolution 9. Ring 10. Uncompressed
II.EXPAND
VIRUS – Vital Information Resource Under Siege
FOC – Fibre Optic Cable
MIDI – Musical Instrument Digital Interface
MPEG – Moving Picture Experts Group
AVI – Audio Video Interface
III.MATCH
Worms - Self replicating file
.wav - Audio file format
F-Secure - Anti-virus software
Macro Virus - infects documents and spreadsheet
Star topology - central hub
IV.True or False
1. True 2. False 3. True 4. False 5. True
V.Answer the following:
1. What is Virus? What are its types?
Computer Virus is a program written to alert the way a computer operates without the permission or knowledge of the user.
Types of Viruses:
1) Boot Sector infectors 2) File infectors 3) Macro Viruses 4) e mail virus
5) Trojan Horse 6) worms
2. What is Anti-Virus software ?give example.
The anti-virus is a computer software that helps to detect and eliminate the virus and worms. Ex. Nortan , McAfee , AVG etc.
3. What are the responses of Anti-Virus software?
* Cleaning infected files and system
* Detection of infected programs
* Blocking the user to access an infected file.
4. What is a computer network? How are they connected?
*) A large number of computers inter connected with each other to built a communication is referred as computer network.
*) They are connected by Copper Wire , Fibre Optic Cable (FOC) , Microwave and Infra Red or Satellite.
5. What is the need for networking?
*)Peripheral devices can be shared.
*)Information can be transferred and exchanged.
*)High reliability of data is made possible by providing a critical function of backup.
6. What is meant by file compression ?give example.
File compression is a technique that makes file smaller than their original size so that they take less space on a disk. EX. WinZip ,Win RAR , Comprexx etc.
7. What is Topology?
The structure or layout of a communication channel which connects the network computer is called Topology.
8. What is Multimedia?
*) Multimedia is a construction of audio, video and animation.
*) It reveals a concept visually that grabs the attention of viewers in an effective manner.
9. Why file compression is needed?
*)To reduce the file size the files are compressed.
*)It can be easily sent through internet.
*)They take less space on a disk.
10 What is Hub?
Hub is a device which has several ports where the computers are hooked into it, which is in turn connected to the server.
II.Detail
1.Explain the following: i) Email virus ii)Trojan horse iii) Macro virus
i) Email virus :
It uses Email messages to move around.
These Viruses often replicates itself by automatically.
ii)Trojan horse
These are claim to perform a particular function but infect the computer or even delete the files.
iii) Macro virus
These are infect the built-in- programming languages in MS word and Excel thus infecting the documents and spreadsheets.
2.List out the signs of Virus.
*)New or unusual window appears when booting a system.
*)Programs may corrupt.
*)The computer often reboots automatically.
*)The system seems to be slow down and stops responding.
*)New files with unusual extensions appearing on your computer.
3.Explain the types of Topology.
i) STAR TOPOLOGY
A star network places a hub in the center of the network.
The hub monitors the entire network.
If the hub is lost, the entire network goes down.
ii)RING TOPLOGY
it connects the nodes of the network in a circular shape.
There is no central server
The data always flows in one direction
If a connection is broken the entire network goes down.
iii) BUS TOPOLOGY
it is a common path to which all nodes and shared devices are connected.
If the connection is broken ,it brings down all or part of the network.
iv) TREE TOPOLOGY
Tree topology is the variation of Bus topology
The tree begins from the head end and has several branches.
4.Tabulate different Multimedia File format.
.wav - Audio file format
.midi - Musical Instrument Digital Interface Used for various musical applications
.avi - Audio Video Interleave is a video file format.
.mpeg - Moving Picture Experts Group is for moving picture or video files.
.jpeg - Joint Photographic Experts Group are the picture file format.
.gif - Graphic Interchange Format is either a static picture or animated picture.
5.Write down the procedure to zip a file using WinZip.
Step 1.Open WinZip.
Step 2.Click on file -> New Archive
Step 3. In the dialog box give name and location of the zip file.
Step 4.Click OK.
Step 5.The Add dialog box appears. Select the files to be zipped
Step 6.Click on Add
Now the zipped files will be listed on the WinZip dialog box.