•CLASS-7 
     •COMPUTER 
      •CH-3 
   •COMPUTER VIRUS 
  •ANSWER KEY OF  BOOK 
  WORK AND COPY WORK 
     • Fill in the blanks: (pg-36) 
 1. A  computer  virus  disrupts  the  normal 
   operation of a computer. 
 2. Computer virus results in loss of speed and 
   distruction  of data. 
 3. Stone virus is a type of boot Virus. 
 4.  Creeper virus was first detected on ARPANET. 
 5.  MyDoom is the most expensive virus in the 
   world. 
 6.  Antivirus software are designed to identify, 
   prevent and remove virus from a computer. 
    • State True or False (pg-37) 
 1. A computer virus is similar to biological virus. 
   False(Not similar) 
 2.  All  virus  programs  cause  harm  to  data  or 
   programs. False(Some) 
 3. Trojan  Horses  are  self  replicated.  False  (Not 
   self replicated) 
 4. A worm is similar to a virus in design. True 
 5.  Spyware creates a backdoor on a computer. 
   F(TROJAN HORSE) 
 6. We should not equip our computer with anti 
   virus programs.  False 
    
  • Application Based Questions (pg-37) 
 1. Varsha’s computer has got infected with a virus 
 which  lead  to  the  frequent  hanging  of  the 
 system. Which software will you suggest her to 
 install in order to solve this problem? 
 Ans- Anti-virus software. 
 2. Sumit’s computer is not working properly . The 
 executable files and programs with extensions , 
 like  ,.com  ,.exe,.ovl,.sys,  on  his  PC  have  got 
 infected . What type of virus has entered into his 
 computer? 
 Ans- Program File viruses.