COMPUTER SCIENCE[CBSE 2015]

Time allowed : 3 hours ] [ Maximum marks : 70

General Instructions :
(i) All questions are compulsory.
(ii) Programming Language : Section A refers to C++
(iii) Programming Language : Section B refers to Python.
(iv) Attempt either Section A or Section B.
(v) Section C is compulsory for all.
(vi) It is compulsory to mention ‘Section A’ or ‘Section B’ before attempting the
question paper.

Section – A

(Only for C++ Candidates)
1. (a) Find the correct identifiers out of the following, which can be used for naming
variable, constants or functions in a C++ program : 2
While, for, Float, new, 2ndName, A%B, Amount2, _Counter

(b) Observe the following program very carefully and write the names of those header
file(s), which are essentially needed to compile and execute the following program
successfully : 1
typedef char TEXT[80];
void main()
{
TEXT Str[] = “Peace is supreme”;
int Index=0;
while (Str[Index]!=’\0’)
if (isupper(Str[Index]))
Str[Index++]=’#’;
else
Str[Index++]=’*’;
puts(Str);
}
(c) Observe the following C++ code very carefully and rewrite it after removing
any/all syntactical errors with each correction underlined. 2
Note : Assume all required header files are already being included in the program.
#Define float Max=70.0;
Void main()
{
int Speed
char Stop=’N’;
cin>>Speed;
if Speed>Max
Stop=’Y’;
cout<<Stop<<end;
}
(d) Write the output of the following C++ program code : 2
Note : Assume all required header files are already being included in the program.
void Position(int &C1,int C2=3)
{
C1+=2;
C2+=Y;
}
void main()
{
int P1=20, P2=4;
Position(P1);
cout<<P1<<”,”<<P2<<end1;
Position(P2,P1);
cout<<P1<<”,”<<P2<<end1;
}

(e) Write the output of the following C++ program code : 3
Note : Assume all required header files are already being included in the program.
class Calc
{
char Grade;
int Bonus;
public:
Calc() {Grade=’E’;Bonus=0;}
void Down(int G)
{
Grade–=G;
}
Void Up(int G)
{
Grade+=G;
Bonus++;
}
void Show()
{
cout<<Grade<<”#”<<Bonus<<end1;
}
};
void main()
{
Calc c;
C.Down(2);
C.Show();
C.Up(7);
C.Show();
C.Down(2);
C.Show();
}
(f) Study the following program and select the possible output(s) from the options (i)
to (iv) following it. Also, write the maximum and the minimum values that can be
assigned to the variable NUM. 2
Note :
– Assume all required header files are already being included in the program.
– random(n) function generates an integer between 0 and n – 1.
void main()
{
randomize();
int NUM;
NUM=random(3)+2;
char TEXT[]=”ABCDEFGHIJK”;
for (int I=1;I<=NUM; I++)
{
for(int J=NUM; J<=7;J++)
cout<<TEXT[J];
cout<<end1;
}
}
(i) FGHI (ii) BCDEFGH (iii) EFGH (iv) CDEFGH
FGHI BCDEFGH EFGH CDEFGH
FGHI EFGH
FGHI EFGH
2. (a) What is a copy constructor ? Give a suitable example in C++ to illustrate with its
definition within a class and a declaration of an object with the help of it. 2
(b) Observe the following C++ code and answer the questions (i) and (ii) :
class Traveller
{
long PNR;
char TName[20];
public :
Traveller() //Function 1
{cout<<”Ready”<<end1;}
void Book(long P,char N[]) //Function 2
{PNR = P; strcpy(TName, N);}
void Print() //Function 3
{cout<<PNR << TName <<end1;}
~Traveller() //Function 4
{cout<<”Booking cancelled!”<<end1;}
};
(i) Fill in the blank statements in Line 1 and Line 2 to execute Function 2 and
Function 3 respectively in the following code : 1
void main()
{
Traveller T;
_________ //Line 1
_________ //Line 2
}//Stops here
(ii) Which function will be executed at }//Stops here ? What is this function
referred as ? 1
(c) Write the definition of a class PIC in C++ with following description : 4
Private Members
Pno //Data member for Picture Number (an integer)
 Category //Data member for Picture Category (a string)
 Location //Data member for Exhibition Location
(a string)
 FixLocation //A member function to assign


Category Location //Exhibition Location as per category
Classic Amina //as shown in the following table
Modern Jim Plaq
Antique Ustad Khan
Public Members
– Enter() //A function to allow user to enter values
//Pno, category and call FixLocation() function
– SeeAll() //A function to display all the data members
(d) Answer the questions (i) to (iv) based on the following : 4
class Exterior
{
int OrderId;
char Address[20];
protected:
float Advance;
91/1 6
public:
Exterior();
void Book(); void View();
};
class Paint:public Exterior
{
int WallArea,ColorCode;
protected:
char Type;
public:
Paint();
void PBook();
void PView();
};
class Bill : public Paint
{
float Charges;
void Calculate();
public :
Bill();
void Billing();
void Print();
};
(i) Which type of Inheritance out of the following is illustrated in the above
example ?
– Single Level Inheritance
– Multi Level Inheritance
– Multiple Inheritance
(ii) Write the names of all the data members, which are directly accessible from
the member functions of class Paint.
(iii) Write the names of all the member functions, which are directly accessible
from an object of class Bill.
(iv) What will be the order of execution of the constructors, when an object of
class Bill is declared ?
91/1 7 [P.T.O.
3. (a) Write the definition of a function Alter(int A[], int N) in C++, which should
change all the multiples of 5 in the array to 5 and rest of the elements as 0. For
example, if an array of 10 integers is as follows : 2
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[9]
55 43 20 16 39 90 83 40 48 25
After executing the function, the array content should be changed as follows :
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[9]
5 0 5 0 0 5 0 5 0 5
(b) A two dimensional array P[20] [50] is stored in the memory along the row with
each of its element occupying 4 bytes, find the address of the element P[10] [30],
if the element P[5] [5] is stored at the memory location 15000. 3
(c) Write the definition of a member function Pop( ) in C++, to delete a book from a
dynamic stack of TEXTBOOKS considering the following code is already
included in the program. 4
struct TEXTBOOKS
{
char ISBN[20]; char TITLE[80];
TEXTBOOKS *Link;
};
class STACK
{
TEXTBOOKS *Top;
public:
STACK(){Top=NULL;}
void Push();
void Pop();
~STACK();
};
(d) Write a function REVCOL (int P[] [5], int N, int M) in C++ to display the content
of a two dimensional array, with each column content in reverse order. 3
Note : Array may contain any number of rows.
For example, if the content of array is as follows :
15 12 56 45 51
13 91 92 87 63
11 23 61 46 81
The function should display output as :
11 23 61 46 81
13 91 92 87 63
15 12 56 45 51
91/1 8
(e) Convert the following infix expression to its equivalent Postfix expression,
showing the stack contents for each step of conversion. 2
X / Y + U* (V–W)
4. (a) Write function definition for SUCCESS( ) in C++ to read the content of a text file
STORY.TXT, count the presence of word STORY and display the number of
occurrence of this word. 2
Note :
– The word STORY should be an independent word
– Ignore type cases (i.e. lower/upper case)
Example :
If the content of the file STORY.TXT is as follows :
Success shows others that we can do it. It is possible to
achieve success with hard work. Lot of money does not mean
SUCCESS.
The function SUCCESS( ) should display the following :
3
(b) Write a definition for function Economic ( ) in C++ to read each record of a binary
file ITEMS.DAT, find and display those items, which costs less than 2500.
Assume that the file ITEMS.DAT is created with the help of objects of class
ITEMS, which is defined below : 3
class ITEMS
{
int ID;char GIFT[20]; float Cost;
public :
void Get()
{
cin>>CODE;gets(GIFT);cin>>Cost;
}
void See()
{
cout<<ID<<”:”<<GIFT<<”:”<<Cost<<end1;
}
float GetCost(){return Cost;}.
};
(c) Find the output of the following C++ code considering that the binary file
CLIENTS.DAT exists on the hard disk with records of 100 members. 1
class CLIENTS
{
int Cno;char Name[20];
public :
void In(); void Out();
};
void main()
{
fstream CF;
CF.open(“CLIENTS.DAT”,ios::binary|ios::in);
CLIENTS C;
CF.read((char*) &C, sizeof(C));
CF.read((char*) &C, sizeof(C));
CF.read((char*) &C, sizeof(C));
int POS=CF.tellg()/sizeof(C);
cout<<”PRESENT RECORD:”<<POS<<end1;
CF.close();
}
5. (a) Observe the following table carefully and write the names of the most appropriate
columns, which can be considered as (i) candidate keys and (ii) primary key. 2

(b) Consider the following DEPT and WORKER tables. Write SQL queries for (i) to
(iv) and find outputs for SQL queries (v) to (viii) : 6

Note : DOJ refers to date of joining and DOB refers to date of Birth of workers.
(i) To display Wno, Name, Gender from the table WORKER in descending
order of Wno.
(ii) To display the Name of all the FEMALE workers from the table WORKER.
(iii) To display the Wno and Name of those workers from the table WORKER
who are born between ‘1987-01-01’ and ‘1991-12-01’.
(iv) To count and display MALE workers who have joined after ‘1986-01-01’.
(v) SELECT COUNT(*), DCODE FROM WORKER
GROUP BY DCODE HAVING COUNT(*)>1;
(vi) SELECT DISTINCT DEPARTMENT FROM DEPT;
(vii) SELECT NAME, DEPARTMENT, CITY FROM WORKER W,DEPT D WHERE
W.DCODE=D.DCODE AND WNO<1003;
(viii) SELECT MAX(DOJ), MIN(DOB) FROM WORKER;
6. (a) Verify the following using Boolean Laws. 2
X + Y' = X.Y+X.Y'+X'.Y'
(b) Draw the Logic Circuit for the following Boolean Expression : 2
(U + V').W' + Z
(c) Derive a Canonical SOP expression for a Boolean function F, represented by the
following truth table : 1

(d) Reduce the following Boolean Expression to its simplest form using K-Map : 3
F(X,Y,Z,W) = S(0,1,6,8,9,10,11,12,15)
7. (a) Illustrate the layout for connecting 5 computers in a Bus and a Star topology of
Networks. 1
(b) What is a spam mail ? 1
(c) Differentiate between ftp and http. 1
(d) Out of the following, which is the fastest (i) wired and (ii) wireless medium of
communication ?
Infrared, Coaxial Cable, Ethernet Cable, Microwave, Optical Fiber 1
(e) What is Worm ? How is it removed ? 1
(f) Out of the following, which all comes under cyber crime ? 1
(i) Stealing away a brand new computer from a showroom.
(ii) Getting in someone’s social networking account without his consent and
posting pictures on his behalf to harass him.
(iii) Secretly copying files from server of a call center and selling it to the other
organization.
(iv) Viewing sites on a internet browser.
(g) Perfect Edu Services Ltd. is an educational organization. It is planning to setup its
India campus at Chennai with its head office at Delhi. The Chennai campus has 4
main buildings – ADMIN, ENGINEERING, BUSINESS and MEDIA.
You as a network expert have to suggest the best network related solutions for
their problems raised in (i) to (iv), keeping in mind the distances between the
buildings and other given parameters.

(i) Suggest the most appropriate location of the server inside the CHENNAI
campus (out of the 4 buildings), to get the best connectivity for maximum
no. of computers. Justify your answer. 1
(ii) Suggest and draw the cable layout to efficiently connect various buildings
within the CHENNAI campus for connecting the computers. 1
(iii) Which hardware device will you suggest to be procured by the company to
be installed to protect and control the internet uses within the campus ? 1
(iv) Which of the following will you suggest to establish the online face-to-face
communication between the people in the Admin Office of CHENNAI
campus and DELHI Head Office ? 1
(a) Cable TV
(b) Email
(c) Video Conferencing
(d) Text Chat
___________