Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Reduce the following Boolean Expression to its simplest form using K-Map:

`E (U, V, Z, W) = sum (2, 3 , 6, 8, 9, 10, 11 , 12 , 13 )`

Reduce the following Boolean Expression to its simplest form using K-Map

`F (X, Y, Z, W) = sum (0, 1, 4, 5, 6, 7, 8, 9, 11, 15)`

Draw the Logic Circuit of the following Boolean Expression

(U' + v).(V' + W')

Draw the Logic Circuit of the following Boolean Expression using only NOR Gates

(A+B).(C+D)

What is a copy constructor? 

Draw the Logic Circuit for the following Boolean Expression: (X'+Y).Z + W'

Draw the Logic Circuit for the following Boolean Expression: (X'+Y).Z + W'

Janish Khanna used a pen drive to copy files from his friend's laptop to his office computer. Soon his computer started abnormal functioning. Sometimes it would restart by itself and sometimes it would stop different applications running on it. Which of the following options out ·of (i) to (iv), would have caused the malfunctioning of the computer? Justify the reason for your chosen option:

1) Computer Virus

2)Spain Mail

3) Computer Bacteria

4) Trojan Horse

What is Trojan Horse?

A text file named MATTER.TXT contains some text which needs to be displayed such that every next character is separated by a symbol '#'.

Write a function definition for HashDisplay() in C++ that would display the entire content of the file MATTER.TXT in the desired format:

Example:

if the file Matter.TXT has the following content stored in it:

THE WORLD IS ROUND

The function HashDisplay() should display the following content:

T#H#E #W#O#R#L#D# #I#S# #R#O#U#N#D#

Write a definition for a function TotalTeachers( ) in C++ to read each object of a binary file SCHOOLS.DAT, find the total number teachers, whose data is stored in the file and display the same. Assume that the file SCHOOLS.DAT is created with the help objects of class SCHOOLS, which is defined below :

class SCHOOLS
{
    int SCode;        //School Code
    char SName[20];   //School Name
    int NOT;          // Name of Teachers in the school

public:
    void Display()
    {
       cout<<SCode<<"#"<<SName<<"#" << NOT << endl;
       int RNOT() {return NOT;}
};

Find the output of the following C++ code considering that the binary file SCHOOL.DAT exists on the hard disk with the following records of 10 schools of the class SCHOOLS as declared in the previous question(4 b)

void main()
{
     fstream SFIN;
     SFIN.open("SCHOOLS.DAT", ios::binary|ios::in) ;
     SCHOOLS S;
     SFIN.seekg(S*sizeof(S));
     SFIN.read((char*)&S, sizeof(S));
     S.Display();
     cout<<"Record : "<<SFIN.tellg()/sizeof(S) + l <<endl;
     SFIN.close();
}

The following C++ code during compilation reports errors as follows:

Error: 'ofstream' not declared

Error: 'strupr' not declared

Error: 'strcat' not declared

Error: 'FIN' not declared

Write the names of the correct header files, which must be included  to compile the code successfully

void main()
{
   of stream FIN ("WISH. TXT") ;
   char TEXT2[]="good day";
   char TEXTl []="John! ";
   
   strupr(TEXT2);
   strcat(TEXTl , TEXT2);
   FIN<<TEXTl<

Anil typed the following C++ code and during compilation, he found three errors as follows :

1) Function strlen should have a prototype

2) Undefined symbol cout

3) Undefined symbol endl

On asking, his teacher told him to include necessary header files in the code. Write the names of the header files, which Anil needs to include, for successful compilation and execution of the following code:

void main()
{
    char Txt[] = "Welcome";
    for(int C= 0; C<strlen(Txt); C++)
       Txt[C] = Txt[C]+ 1;
    cout<<Txt<<endl;
}

Ms Raveena Sen is an IT expert and a freelancer. She recently used her skills to access the Admin password for the network server of Super Dooper Technology Ltd. and provided confidential data of the organization to its CEO, informing him about the vulnerability of their network security. Out of the following options (i) to (iv), which one most appropriately defines Ms Sen?

Justify the reason for your chosen option :
1) Hacker

2) Cracker

3) Operator

4) Network Admin

Out of the following, which all comes under cyber crime ?

1) Stealing away a brand new hard disk from a showroom

2) Getting in someone's social networking account without his consent and posting on his behalf

3) Secretly copying data from server of an organization and selling it to the other organization.

4) Looking at online activities of a friends blog.

Observe the following program very carefully and write the names of those header files (s), which are essentially needed to compile and execute the following program successfully :

typedef char STRING[80];
void main()
{
    STRING Txt[] ="We love Peace";
    int Count=O;
    while(Txt[Count]!='\0')
    if (isalpha(Txt[Count]))
       Txt[Count++]='@';
    else
       Txt[Count++]='#';
    puts(Txt);
}

Write function definition for TOWER() in C++ to read the content of a text file WRITEUP.TXT, count the presence of word TOWER and display the number of occurrences of this word.

Note:

•  The word TOWER should be an independent word
• Ignore type cases (i.e. lower/upper case)

Example:

If the content of the file WRITEUP.TXT is as follows:

The function TOWER( ) should display the following :

Look at the following C++ code and find the possible output from the options (i) to (iv) following it. Also, write the highest and lowest values that can be assigned to the array A.

Note:

• Assume all the required header files are already being included in the code
• The function random(n) generates an integer between 0 and -1

void main()
{
   randomize();
   int A(4], C;
   for(C=0; C<4; C++)
      A(C] = random(C+l) + 10;
   for (C=3; C >= 0; c--)
       cout<<A(C]<<"@";
}

1) 13@10@11@10@

2) 15$14$12$10$

3) 12@11@13@10@

4) 12@11@10@10@

Find and write the output of the following C++ program code :
Note : Assume all required header files are already being included in the program.

void main()
{
     int *Point, Score[]={100,95,150 , 75 , 65, 120};
     Point = Score;
     for(int L = 0; L<6; L++)
     {
         if((*Poi nt)%10==0)
            *Point /= 2;
         else
            *Point -= 2;
         if((*Point) %5==0)
            *Point /= 5;
         Point++;
      }
      for(int L = 5; L>=O; L--)
          cout<<Score[L]<<"*";
}