Computer Science
Class-VI
Chapter-11 Computer: Problem and Protection
A. Tick the correct answer:
1. CMJ is a type of which of the following viruses?
a. boot virus b. resident virus c. macro virus
Answer: Resident Virus
2. Which among the following are encrypted segments of other important programs?
a. time bombs b. logical bombs c. worms
Answer: Logical Bombs
3. Which of the following refers to the crimes that are conducted over the internet?
a. hacking b. cyber crime c. cracking
Answer: Cyber Crime
4. Which of the following means using logic to guess the pasword?
a. cracking b. hacking c. virus programming
Answer: Cracking
5. What is the process called by which a virus is sent to other computers?
a. virus programming b. hacking c. cracking
Answer: Virus Programming
B. Fill in the blanks:
1. ________________ can affects the normal functioning of a computer.
Answer: Computer virus
2. ___________________ virus stays permanently in the ram of computer.
Answer: Resident
3. _______________ virus is found in the main file of the hard disk.
Answer: Direct Action
4. Boot virus is stored in the boot sector of a ___________.
Answer: Floppy
5. __________________ affects the files that contain macros.
Answer: Macro Virus
C. Match the following:
Column A Column B
1. Mrklunky i. Macro virus
2. Trivial ii. File infectors
3. Form iii. Resident virus
4. Melissa iv. Overwrite virus
5. Raindrop v. Boot virus
Answer:
1. iii.
2. iv.
3. v.
4. i.
5. ii.
D. Write true or false:
1. Directory virus infects the files and changes the path address of files.
Answer: T
2. Polymorphic virus does not replicate itself.
Answer: F
3. File infector affects all .exe and .com file.
Answer: T
4. Worms is a program designed to faster up the operating speed of a computer.
Answer: F
5. Trojans enter through removable data storage device.
Answer: T
E. Answer the following questions:
1. What is a computer virus? How can it harm a computer?
Answer: A computer virus is a computer program that is written with the intention of affecting a computer.
It is a small, hidden program that affects the normal functioning of your computer.
2. Define overwrite virus and polymorphic virus.
Answer: Overwrite Virus: Overwrite virus is amongest the most dangerous viruses, as it causes total loss of data.
Polymorphic Virus: It replicates and makes a large number of copies of themselves. Every time it infects a system, it encodes itself in a different way.
3. What are the symptoms of virus infection?
Answer: Symptoms of virus infection:
* The operating speed of the computer gets greatly reduced.
* Instead of the original files, you see undecipherable characters in your file.
* The last modified date changes.
4. Write the various ways of protecting computer system from virus attack.
Answer: Various ways of protecting computer system from virus attack:
* Make backup copies of all the data.
* Do not use pirated software.
* Do not visit sites that have not been authorized.
5. Differentiate between hacking and cracking.
Answer: Hacking refers to the process of breaking into a computer with the intention of stealing information from the computer.
Cracking: Cracking refers to the process of cracking into a computer with the purpose of stealing the passwords of the computer, files or programs.
Some Other Links: