CBSE Board Computer Science Sample Papers for Class 11

Sample Paper
Class – XI
Subject – Computer Science

Time: 3Hours                                                                        Maximum Marks: 70
Note.  (i)  All questions are compulsory.
           (ii) Programming Language: C++

1 a) What is an operating system? Explain its types?          2
    b) What is the difference b/w Data & Information?                       2
    c)  (i) Storage of 1 KB means the following number of bytes :                          2
            1) 1000    2) 964 3) 1042 4) 1024                                                                                                   
          (ii) One Megabyte is equivalent to
              1) 210 Bytes    2) 220 Bytes 3) 230 Bytes 4) None of these.
   d) State the basic units of the computer, Name the subunits that make up the CPU and give the function of each of the units.             2
   e) Define System Software and what are its two main types? Give examples.2
    f) What is Booting?             1
   g) Which of the following are hardware and software?              1
    (i) Capacitor (ii) Internet Explorer (iii) Hard disk (iv) UNIX

2 a) What is the difference b/w “while” & “do while” loop?                         2
  b) What are data types? What are all predefined data types in c++?                2
  c) What will be the size of following constants?                                                 1
        ‘\v’,”\v”,
d) Write the corresponding C++ expressions for the following mathematical expressions:         1
         i) √ (a2+b2+c2)                          (ii) p+q/(r+s) 4
e) Evaluate the following, where a, b, c are integers and d, f are floating point numbers.
        The value of a=8, b=4 and d=2.5
(i)f = a * b  + a/b
(ii)c = d+a + b % a                                                      2

3 a) What is the output of the following?            2
       i)   # include<iostream.h>
             void main ( )
   {
      int i=0;
      for (i=1; i<=20;i++)
        {
          cout<<i<<endl;
          i=i+2;
          }
}
     ii)    # include<iostream.h>
           void main( )
   {
     a=3;
     a=a+1;
     if (a>5)
        cout<<a;
    else
        cout<<(a+5);      
}                                 2
    iii) What will be the output of the following program segment?                         3
           If input is as:           (a) c (b) m (c) a (d) v
          
           cin >>ch;    
           switch (ch)
            { case ‘c’: cout<<”Computer Science”;
              case ‘m’: cout<<”Mathematics”;
                             break;
              case ‘a’: cout<<”Accoutant”;
                            break;
              default: cout<<” wrong choice”;    
           }                              
  iv) Determine the output:
                        2
      for(i=10;i<=50;i+=10)
          {
           j=i/2;
           cout<<j<<””;
          }
   v) What output will be the following code fragment produce?
          void main( )
          {
   int val, res, n=1000;
  cin>>val;
             res = n+val >1750 ? 400:200;
             cout<<res;
          }
         (i) if val=2000 (ii) if  val=1000 (iii) if val=500           3



4 a) Find the error from the following code segment and rewrite the corrected code underlining the correction made.                     2
      
  # include(iostream.h)
          void main ( )
           int X,Y;
           cin>>X;
           for(Y=0,Y<10, Y++)
              if X= =Y
                       cout<<Y+X;
             else
                      cout>>Y;       }    
  b) Convert the following code segment into switch case construct.                  3                                                                                               

    int ch;
cin>>ch;
If(ch = = 1)
{ cout<<“ Laptop”;
      } 
         else If(ch = = 2)
  {
  cout<<“Desktop ”;
      }    else if(ch= = 3)
                  { 
                    cout<<“Notebook”;
                  } else
                             {
                  cout<<“Invalid Choice”;
                     }
  }
}

c) Convert the following code segment into while loop.                                        3                    
      #include<iostream.h>
             void main()
        {   int i;
                     for(i=1;i<=20;++i) 
             cout<<”\n”<<i;
                   }


d) Given the following code fragment
        int ch=20;
        cout << ++ch<< “\n”<<ch<<”\n”;

i)What output does the above code fragment produce?
ii)What is the effect of replacing ++ ch with ch+1?              2

5 a) Which header files are required for the following?
      (i) puts ( ) (ii) sqrt( ) (iii) clrscr( ) (iv) strlen( )         2

   b) Evaluate:         4
i)     (120)10 = ( X)2
ii)   (110001)2=(X)10
   iii)  (0100011)2=(X)10
    iv) (97)10=(X)2

6 a) Write a C++ program to check a year for leap year or not.                             2
   b) Write a C++ program to check a number for Armstrong or not.                      4                  
   c) Write a C++ program to print day of the week corresponding to the number   (1-7) entered using switch case statement.                                                           4
  d) Write a C++ program to design a menu for calculator and calculate the following operations :
   1 for addition,2 for subtraction,3 for multiplication, 4 for division, 5 for exit the program.                   4                                           
   e) Write a C++ program to print table a given number.                   2
      

7. Explain the following term: (Give answer any six)         6

   i)  Variable
   ii) Token
   iii) Array
   iv) Debugging
   v) Comment
   vi) Keyword
   vii) Structure