CBSE Board Class 12 Computer Science Previous Year Question Papers 2007


CBSE Board Previous Year Question Papers 2007 for Class 12 Computer Science

Previous Paper – 2007
Class – XII
Subject – Computer Science
Q. 1.
a.Name the header file to which the following belong:       (1)
(i) gets( )
(ii) open( )
b.What is copy constructor? What do you understand by constructor overloading?     (2)
c.Rewrite the following program after removing the syntactical error(s), if any Underline each correction,            (2)
#include <iostream.h>
void main( )
{     struct TV
      {     char Manu_name[20];
            char Tv_Type;
            int Price = 17000;
}     New Tv;
      gets(Manu_name);
      gets(Tv_Type);
}
d.Find the output of the following program:        (3)
#include<iostream.h>
#include<string.h>
class country
{        char *country name;
        int length;
        public:
        country ( ) {Iength =0; country_name=new char [length+1];}
        country (char *s)
        {        length = strlen(s); country_name=new char [length +1];
                 strcpy (country_name, s);
        }
        void display () { cout<< country_name <<endl;}
        void Replace (country & a, country & b)
        {        length a.length + b.length;
                delete country_name;
                country_name=new char [length + 1];
                strcpy (country_ name, a.country_name);
                strcat (country_name, b.country name);
                }
};
void main ( )
{       char * temp = “India”;
        country country1 (temp), country2 (“Nepal”), country3 (“China”), S1,S2;
        S1.Replace (country1, country2);
        S2.Replace (S1,country3);
        S1.display( );
        S2.display ( );
}
e.Find the output of the following program:        (2)
#include<iostream.h>
struct list
{  int a, b;
};
void main()
{
list s[3]={{12,14},{2,3},{4,5}};
for(int i=0;i<3;i++)
cout<<s[i].a+s[i].b<<"\t";
}
f.What is the importance of constructor in object oriented programming? Explain with the help of an example.            (2)

Q. 2.
a.What is the difference between Multilevel and Multiple Inheritance in context to object oriented programming?            (2)
b.Given a class as follows:         (2)
class Match
{     int Time;
      public:
      Match (int y) { Time = y;}       //Constructor 1
      Match (Match& t);                  //Constructor 2
};
i.Create an object, such that it invokes Constructor 1.
ii.Write complete definition for Constructor 2.
c. Define a class ELECTION with the following specifications . Write a suitable main ( ) function also to declare 3 objects of ELECTION type and find the winner and display the details .   (4)

Private members :
Data :  candidate_name , party , vote_received
Public members :
Functions  : enterdetails ( ) – to input data
    Display ( ) – to display the details of the winner
    Winner ( ) – To return the details of the winner trough the object after comparing the votes received by three candidates .
a.Answer the questions (i) to (iii) based on the following code:
class toys
{
      char Code;
      char Manufacturer [10];
      public:
      toys( );
      void Read_toy_details ( );
      void Disp_toy_details( );
};
class electronic : public toys
{
      int no_of_types;
      float cost_of_toy;
      public:
      void Read_elect_details ( );
      void Disp_elect_details ( );
};
      class infants : private electronic
{
      int no_of_buyers;
      char delivery date[10];
      public:
      void Read_infant_details ();
      void Disp_jnfant_details();
};
void main ( )
{       infants MyToy;      }
(i) Mention the member names which are accessible by MyToy declared in main () function.  (1)
(ii) What is the size of MyToy in bytes?         (1)
(iii) Mention the names of functions accessible from the member function Read_infant_details () of   class printer.            (2)

Q. 3.
a.Write a function in C++ which accepts an integer array and its size as arguments/ parameters and then assigns the elements into a two dimensional array of integers in the following format:  (4)
If the array is 1, 2, 3, 4, 5, 6
The resultant 2 D array is given below
If the array is 1, 2, 3
The resultant 2 D array is given below

b.An array MAT [15] [7] is stored in the memory along the column with each element occupying 2 bytes of memory. Find out the base address and the address of element MAT [2] [5], if the location of MAT [5] [4] is stored at the address 100.        (4)
c.What is circular queue? How is it different from simple queue?
Write a function in C++ to perform Delete operation in dynamically allocated Queue containing names of students.           (4)
d.Write a function in C++ called shift( ) to rearrange the matrix as shown . Do not use parallel matrix .            (2)
Original Matrix    Rearranged Matrix
1 2 -3 -2  -3 -2 1 2
0 -1 2 1  -1 0 2 1
-3 9 -4 4  -3 -4 9 4
e.Evaluate the following postfix expression using a stack and show the contents of the stack after execution of each operation.         (2)
10, 20,*,10,2,/,+

Q. 4.
a.Write a function to count the number of VOWELS present in a text file named “PARA.TXT”.  (3)
b.Write a function in c++ to open the text file “oneindia.dat” and add one more record of following structure type. The file has already existed with some records.     (3)
struct  India
{
char name[25];
float amount;
};

Q. 5.
a.   What do you understand by Foreign  key and cardinality in a relation.     (2)
b. Consider the following tables SCHOOL and ADMIN. Write SQL commands for  the statements (i) to (iv) and give outputs for SQL queries (v) to (viii).       (1x4 + ½ x 4 = 6)
Table: SCHOOL        
CODE
TEACHERNAME
SUBJECT
DOJ
PERIODS
EXPERIENCE
1001
RAVI SHANKAR
ENGLISH
12/03/2000
24
10
1009
PRIYA RAI
PHYSICS
03/09/1998
26
12
1203
LISA ANAND
ENGLISH
09/04/2000
27
5
1045
YASHRAJ
MATHS
24/08/2000
24
15
1123
GANAN
PHYSICS
16/07/1999
28
3
1167
HARISH B
CHEMISTRY
19/10/1999
27
5
1215
UMESH
PHYSICS
11/05/1998
22
16
Table: ADMIN
CODE
GENDER
DESIGNATION
1001
MALE
VICE PRINCIPAL
1009
FEMALE
COORDINATOR
1203
FEMALE
COORDINATOR
1045
MALE
HOD
1123
MALE
SENIOR TEACHER
1167
MALE
SENIOR TEACHER
1215
MALE
HOD

i)To display TEACHERNAME, PERIODS of all teachers whose periods less than 25 and  name start with either R or U..
ii)Display all from table SCHOOL from where period is between 10 and 20.
iii)To display TEACHERNAME, CODE  and DESIGNATION from  tables SCHOOL  and    ADMIN for female teacher..
iv)To display CODE, TEACHERNAME and SUBJECT of all teachers who have joined the   school after 01/01/1999.
v) SELECT MAX(EXPERIENCE), SUBJECT FROM SCHOOL GROUP BY SUBJECT;
vi) SELECT TEACHERNAME, GENDER
      FROM SCHOOL, ADMIN
      WHERE DESIGNATION = ‘COORDINATOR’ AND
      SCHOOL.CODE=ADMIN.CODE ;
vii)  SELECT DESIGNATION, COUNT(*) FROM ADMIN
       GROUP BY DESIGNATION HAVING COUNT(*) <3;
viii)  SELECT COUNT(DISTINCT SUBJECT) FROM SCHOOL;

Q. 6.
a.State and verify Absorption law.          (2)
b.Write the equivalent expression for the following logical circuit:      (2)

c.Express P’ + QR’ in canonical SOP form.       (2)
d.Reduce the following Boolean expression using K-Map:      (2)
F(P,Q,R,S)=∑(l,3,5,8,11,12,15)

Q. 7.
(a)  Write the difference between coaxial and optical fiber cable.      (1)
(b)  Explain the following terms in short :         (1)
(i) GSM  ii) CDMA
(c)  What us the difference between Message switching technique and Packet switching technique ? (1)
(d) Expand the following :          (1)
TCP/IP, XML, CDMA, WLL
(f)  Haldiram Private Ltd. has decided to network all its offices spread in five buildings of Company (Shown below). No. of computers given in square brackets [ ].    

The distance between buildings are  given below:
Between 1 & 2
20 Mts

Between 3 & 5
70 Mts
Between 2 & 3
50 Mts

Between 1 & 5
65 Mts
Between 3 & 4
120 Mts

Between 2 & 5
50 Mts
Between 4 & 5
30 Mts

(i)  Suggest cable layout(s) for connecting the buildings.       1
(ii)  Suggest the most suitable building to install the server of this organization with a suitable reason, with justification.            1
(iii)  Building-3 is used for many critical operations. It is tried that PC gets maximum possible bandwidth. Which network device is/should be used for this?       1
(iv)  The company also has another office in the same city but at a distant location about 25-30 kms away. How can link be established with this building. (i.e. suggest the transmission medium).  1