### 12th Standard CBSE Computer Science Study material & Free Online Practice Tests - View and download Sample Question Papers with Solutions for Class 12 Session 2019 - 2020 CBSE

#### 12th CBSE Computer Science Review of C++ Model Question Paper 2 - by Ekta Bhalla - Kottayam Aug 20, 2019 - View & Download

• 1)

Generally there are four data types, each of which can be signed or unsigned.Write names of all four data types.

• 2)

If v is an identifier of int type and is holding value 255. Is the following statement correct?
char code = v;

• 3)

Do you see any similarity between a typedef name and a reference name? If yes, what is it?

• 4)

Which value of x will be printed in following case and why?
int x=9;
void main()
{
int x = 10;
cout<<x;
}

• 5)

In the following program:
i) How many times will the while loop run?
ii) What would be the last value of A displaced out?
#include<iostream.h>
void main()
{
int A=10;
while(++A<15)
{
cout<<A++;
}
}

#### 12th Standard CBSE Computer Science Unit 7 Communication Technologies Model Question Paper - by Ekta Bhalla - Kottayam Aug 03, 2019 - View & Download

• 1)

Which of the network (out of LAN, PAN and MAN) is formed, When you connect two mobiles using Bluetooth to transfer a picture file?

• 2)

Write one advantage of bus topology of the network. Also, illustrate how four computers can be connected with each other using star topology of network?

• 3)

Expand the following abbreviations:

(i) HTTP                     (ii) ARPANET

• 4)

What is a protocol? Which is used to search information from internet using an internet.

• 5)

What is the advantage of using SWITCH over HUB?

#### 12th Standard CBSE Computer Science Unit 6 Boolean Algebra Sample Question Paper - by Ekta Bhalla - Kottayam Jul 31, 2019 - View & Download

• 1)

Write the Product of Sum(POS) form of the function F(X, Y, Z) for the following truth table representation of F:

 X Y Z F 0 0 0 1 0 0 1 0 0 1 0 0 0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 1 1 1 1 1
• 2)

Write the dual of the boolean expression $(A+0).(A.1.\bar { A } )$

• 3)

Find the complement of the following boolean function ${ F }_{ 1 }=A.B+\bar { C } .\bar { D }$ :

• 4)

Why are NAND and NOR gates called Universal gates?

• 5)

Express $P+\bar { Q } .R$ in canonical SOP form

#### 12th CBSE Computer Science Unit 5 Database and SQL Important Question Paper - by Ekta Bhalla - Kottayam Jul 29, 2019 - View & Download

• 1)

What are DDL and DML?

• 2)

Differentiate between SQL commands DROP TABLE and DROP VIEW.

• 3)

Write a query on the SALESPEOPLE table, whose output will exclude all salespeople with a rating >=100, unless they are located in Delhi.

• 4)

What is the difference between degree and cardinality of a table? What is the degree and cardinality of the following table?

 Eno Name salary 101 John Fedrick 45000 102 Raya Mazumdar 50600

Differentiate between the terms degree and cardinality in context of RDBMS.

• 5)

Explain the concept of candidate keys with the help of an appropriate example.

#### 12th CBSE Computer Science Unit 4 Data Structure and Pointers Important Question Paper - by Ekta Bhalla - Kottayam Jul 27, 2019 - View & Download

• 1)

An array circular queue[10] of integers exixt,where currently
Rear=0, Front=1
Answer the following questions based on the above given data:
(i) How many values arte there in queue?
(ii) If five valuesare deleted,whatwould be the new value of Front?

• 2)

How wil you know that a linear queue is full?

• 3)

Suppose a circular queue maintained by an array Q with 12 memory locations and Front and Rear are the two pointers.
Find the number of elements in Q when:
(i) Front=4, Rear=8
(ii) Front=10, Rear=3
(iii) Front=5, Rear=6
and then two elements are deleted.

• 4)

What are the drawbacks of linear queue?

• 5)

Write code for a function void Convert(int T[], int Num) in c++, which reposition all the elements of the array by shifting the element to the last position.

 0 1 2 3 4 22 25 70 32 12

The changed content will be:

 0 1 2 3 4 25 70 32 12 22

#### 12th Standard CBSE Computer Science Unit 3 Data File Handling in C++ Important Question Paper - by Ekta Bhalla - Kottayam Jul 26, 2019 - View & Download

• 1)

Write a function COUT_TO() in C++ to cout the presence of aworld 'to' in text file NOTES.TXT is as it is very important to know that smoking is injurious to health,let us take initiative to stop it.The function COUT_TO()will display the following message cout of-to=in file:3

• 2)

Write a function EUCout() in C++,which should reads each character of a a text file.IMP.TXT,should count and display the occurrence of
alphabets E and U (including small case e and u too). e.g. if the file contain is as follows: Update information is simplified by official websites.The EUCount() function should display the output as:
E:4
U:1

• 3)

Write a function in C++ to search for the details(phone no and Calls) of those phons, which have more than 1000 calls from a binary file phons.dat. Assuming that this binary file contains records? objects of class phone, which is defined below.
class phone
{
char phoneno[10];
int calls;
public:
void get(){gets(phoneno);
cin>>calls;
void billing(){cout<<int getCalls(){return calls;}
};

• 4)

Write a function in C++ to count the words "to" and "the" present in a text file POEM.TXT.(Note that the words "to" and "the" are complete words.)

• 5)

Write a function to count the member of words prsent in a text file named PAPER.TXT.Assume that each word is separated by a single blank/space in the beginning and end of the file.

#### 12th CBSE Computer Science Unit 2 Object Oriented Programming in C++ Important Question Paper - by Ekta Bhalla - Kottayam Jul 25, 2019 - View & Download

• 1)

How are the object's behaviour and object's characteristics represented in OOP?

• 2)

• 3)

How are abstraction and encapulation interrelated?

• 4)

Inheritance allows code reusability in OOp.Explain how?

• 5)

Observe the program segment carefully and answer the question that follows: class member
{
int member_no;
char member_name[20];
public:
void enterDetail( );
void showDetail( );
int getMember_no( ){ return member_no;}
};
void update(member NEW )
{
fstream File;
File.open( “member.dat”, ios::binary|ios::in|ios::out) ;
member i;
while(File .read((char*) & i , sizeof (i)))
{
if(NEW . getMember_no( ) = = i . getMember_no( ))
{
___________//missing statement
File.write((char*) &NEW , sizeof (NEW));
}
}
File.close() ;
}
If the function update( ) is supposed to modify the member_name field of a record in the file “ member.dat” with the values of member NEW passed as argument, write the appropriate statement for the missing statement using seekp( ) or seekg( ), whichever is needed, in the above code that would write the modified record at its proper place.

#### CBSE 12th Computer Science Unit 1 Review Of C++ Important Question Paper - by Ekta Bhalla - Kottayam Jul 24, 2019 - View & Download

• 1)

Generally there are four data types, each of which can be signed or unsigned.Write names of all four data types.

• 2)

How 'I' operator is different from '%' operator?

• 3)

What is wrong with the following C++ statement?
long float y;

• 4)

Differentiate between an identifier and keywords.

• 5)

Show two different ways to declare as integer variable named intname and set its value to 15.

#### Computer Science CBSE Class 12 Pre Public Model Exam Question Paper with Answer Key - by KARTHIK S M Dec 29, 2018 - View & Download

• 1)

Which value of x will be printed in following case and why?
int x=9;
void main()
{
int x = 10;
cout<<x;
}

• 2)

• 3)

Create a table named PROGRAMMERS with the following structure:

 P_Name 20 Characters DOJ Date SAL NUMBER

i) Display the name of the programmer, which has the highest salary.
ii) Update the salary of all programmer by 2000 whose name start with letter 'R'.

• 4)

State the distributive laws of boolean algebra. How do they differ from the distributive laws of ordinary algebra?

• 5)

What is the difference between video conferencing and chat?

#### 12th Grade CBSE Computer Science HOTs question paper and answer key - by KARTHIK S M Dec 29, 2018 - View & Download

• 1)

Is it necessary to include a header file in a program? If it is not done, what happens?

• 2)

How does a compiler decide as to which function should be invoked when there are many functions with the same name?

• 3)

Give the SQL statement to create a table STUDENT with Roll Number, Name, Age and Marks.

• 4)

Write the Product of Sum(POS) form of the function F(X, Y, Z) for the following truth table representation of F:

 X Y Z F 0 0 0 1 0 0 1 0 0 1 0 0 0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 1 1 1 1 1
• 5)

Write the full form of the following:
(i) GNU
(ii) XML

#### Computer Science CBSE Class 12 NCERT based Questions and Answer - by KARTHIK S M Dec 29, 2018 - View & Download

• 1)

How 'I' operator is different from '%' operator?

• 2)

How does a compiler decide as to which function should be invoked when there are many functions with the same name?

• 3)

Differentiate between SQL commands DROP TABLE and DROP VIEW.

• 4)

Write the Product of Sum(POS) form of the function F(X, Y, Z) for the following truth table representation of F:

 X Y Z F 0 0 0 1 0 0 1 0 0 1 0 0 0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 1 1 1 1 1
• 5)

What is voip?

#### 12th CBSE Computer Science Data Structure and Pointers Important Questions - by KARTHIK S M Dec 14, 2018 - View & Download

• 1)

Suppose a data structure is stored in a circular queue with N memory locations what will be the queue full condition?

• 2)

How wil you know that a linear queue is full?

• 3)

What do Front and Rear signify in a queue? if in a queue, the Rear points to the Front, how many elements are there in queue?

• 4)

Consider a queue of size 5.Insert elements 2,4,6,8 and then delete first two elements.After deleting, insert 10,12 in the queue.Show the status of Front and Rear in each step.

• 5)

Write a Get1From2() function in c++ to transfer the content from two array FIRST[] and SECOND[] to array ALL[].the even places(0,2,4...) of array ALL[] should get the content from the array First[] and odd places (1,3,5,...) of the array ALL[] should get the content from the array SECOND[].
e.g if the FIRST[]array contain
30,60,90
and the SECOND[] array contains
10,50,80
The ALL[] array should contain
30,10,60,50,90,80

#### 12th Computer Science Database and SQL Important Question Paper - by KARTHIK S M Dec 10, 2018 - View & Download

• 1)

What are DDL and DML?

• 2)

Give the SQL statement to create a table STUDENT with Roll Number, Name, Age and Marks.

• 3)

Create a table named PROGRAMMERS with the following structure:

 P_Name 20 Characters DOJ Date SAL NUMBER

i) Display the name of the programmer, which has the highest salary.
ii) Update the salary of all programmer by 2000 whose name start with letter 'R'.

• 4)

Explain the concept of candidate keys with the help of an appropriate example.

• 5)

Explain the concept of cartesian product between two tables, with the help of an appropriate example.

#### 12th CBSE Computer Science Boolean Algebra Important Question - by KARTHIK S M Dec 01, 2018 - View & Download

• 1)

Write the Sum of Product(SOP) form of the function F(P,Q, R) for the following truth table representation of F:

 P Q R F 0 0 0 1 0 0 1 0 0 1 0 0 0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 1 1 1 1 1
• 2)

Write the dual of the boolean expression $(A+0).(A.1.\bar { A } )$

• 3)

How many input combinations can be there in the truth table of a logic system having(N) input binary variables?

• 4)

Verify the following using boolean laws:

$A+C=A+\overset { - }{ A } .C+B.C$

• 5)

Verify the following algebraically:$\bar { X } .Y+X.\bar { Y } =(\bar { X } +\bar { Y } ).(X+Y)$

#### 12th CBSE Computer Science Communication Technologies Important Question Paper - by KARTHIK S M Nov 30, 2018 - View & Download

• 1)

Which of the network (out of LAN, PAN and MAN) is formed, When you connect two mobiles using Bluetooth to transfer a picture file?

• 2)

Write one advantage of star topology of network? Also, illustrate how five computers can be connected with each other using star topology of ntework

• 3)

Name any two components required for networking.

• 4)

Expand the following abbreviations:

(i) HTTP                     (ii) ARPANET

• 5)

Which of the following crime(s) is/are covered under cyber crime?

(i) stealing brand new hard disk a shop.

(ii) getting into unknown person's social networking account and start messaging on his behalf .

(iii) Copying some important data from a computer without taking permission from the owner of the data.

#### 12th Standard Computer Science Revision Model Question Paper 1 - by KARTHIK S M Nov 29, 2018 - View & Download

• 1)

Generally there are four data types, each of which can be signed or unsigned.Write names of all four data types.

• 2)

Observe the following C++ code and write the name(s) of the header file(s), which will be essentially required to run it in a C++ compiler.
void main()
{
char Text[20],C;
cin>>Text;
C=tolower(Text[0]);
cout<<c<<"is the first char of"<<Text<<endl;
}

• 3)

Write the names of the header files, which is/are essentially required to run/execute the following C++ code.
void main()
{
char CH,Text[]="+ve Attitude";
for(int I=0;Text[I]!='\0';I++)
if(Text[I]=='  ')
cout<<endl;
else
{
CH=toupper(Text[I]);
cout<<CH;
}
}

• 4)

A function printing is defined as
void printing(char c= '*', int l=40)
{
for(int x=0;x<1;x++)
cout<<c;
cout<<endl;
}
How will you invoke the function printing for following output:
i) to print '*' 40 times
ii) to print '=' 30 times

• 5)

What are nested structures? Give an example.

#### Class 12 CBSE Computer Science Important Questions - by KARTHIK S M Sep 15, 2018 - View & Download

• 1)

Create a table named PROGRAMMERS with the following structure:

 P_Name 20 Characters DOJ Date SAL NUMBER

i) Display the name of the programmer, which has the highest salary.
ii) Update the salary of all programmer by 2000 whose name start with letter 'R'.

• 2)

How many input combinations can be there in the truth table of a logic system having(N) input binary variables?

• 3)

Why are NAND and NOR gates called Universal gates?

• 4)

Consider the following supplier table:
TABLE: Supplier

 Suppcode Lastname Firstname City 1 Jain Anuj Noida 2 Goel Pooja Kanpur 3 Sharma Raman Delhi 4 Gupta Satish Noida

Write a query to find all suppliers, who reside in Noida and also give the resultant table.

• 5)

What is the need of normalization?

#### 12th Standard CBSE Computer Science Model Test - by KARTHIK S M Sep 15, 2018 - View & Download

• 1)

Give the output of the following program:
int a=44;
cout<<a++<<"\t"<<a<<"\n"<<++a;
cout<<endl<<a<<endl;

• 2)

What is the effect of absence of break in switch-case statement?

• 3)

How many times is the loop executed?
int i=0, j=0;
do
{
i=j;
}
while(j<5);

• 4)

Observe the following C++ code and write the name(s) of the header file(s), which will be essentially required to run it in a C++ compiler.
void main()
{
char Text[20],C;
cin>>Text;
C=tolower(Text[0]);
cout<<c<<"is the first char of"<<Text<<endl;
}

• 5)

Observe the following C++ code and write the name(s) of the header file(s),which will be essentially required to run it in a C++ compiler.
void main()
{
int Number;
cin>>Number;
if(abs(Number)==Number);
cout<<"Positive"<<endl;
}

#### Communication Technologies - Important Questions Model Paper In 12th Computer Science - by KARTHIK S M Jul 31, 2018 - View & Download

• 1)

Which of the network (out of LAN, PAN and MAN) is formed, When you connect two mobiles using Bluetooth to transfer a picture file?

• 2)

Write one advantage of star topology of network? Also, illustrate how five computers can be connected with each other using star topology of ntework

• 3)

What is the function modem?

• 4)

What is hub?

• 5)

What is the advantage of using SWITCH over HUB?

#### Boolean Algebra - Important Questions Model Paper In 12th Computer Science - by KARTHIK S M Jul 30, 2018 - View & Download

• 1)

Write the Sum of Product(SOP) form of the function F(P,Q, R) for the following truth table representation of F:

 P Q R F 0 0 0 1 0 0 1 0 0 1 0 0 0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 1 1 1 1 1
• 2)

Write the Product of Sum(POS) form of the function F(X, Y, Z) for the following truth table representation of F:

 X Y Z F 0 0 0 1 0 0 1 0 0 1 0 0 0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 1 1 1 1 1
• 3)

Write the product of Sum (POS) form of the function G(U,V,W) for the following truth table representation of G:

 U V W G 0 0 0 1 0 0 1 0 0 1 0 1 0 1 1 0 1 0 0 1 1 0 1 0 1 1 0 0 1 1 1 1
• 4)

Write the Sum of Product(SOP) form of the function F(A,B,C) for the following truth table representation of F:

 A B C F 0 0 0 0 0 0 1 0 0 1 0 1 0 1 1 1 1 0 0 1 1 0 1 0 1 1 0 0 1 1 1 1
• 5)

Write the dual of the boolean expression $(A+0).(A.1.\bar { A } )$

#### Database And Sql - Important Questions Model Paper In 12th Computer Science - by KARTHIK S M Jul 30, 2018 - View & Download

• 1)

What are DDL and DML?

• 2)

Write a query on the SALESPEOPLE table, whose output will exclude all salespeople with a rating >=100, unless they are located in Delhi.

• 3)

What is the difference between degree and cardinality of a table? What is the degree and cardinality of the following table?

 Eno Name salary 101 John Fedrick 45000 102 Raya Mazumdar 50600

Differentiate between the terms degree and cardinality in context of RDBMS.

• 4)

What do you mean by the union and cartesian product operation in relational algebra?

• 5)

Give a suitable example of a table with sample data and illustrate primary and alternate keys in it.

#### Data Structure And Pointers - Important Questions Model Paper In 12th Computer Science - by KARTHIK S M Jul 30, 2018 - View & Download

• 1)

An array circular queue[10] of integers exixt,where currently
Rear=0, Front=1
Answer the following questions based on the above given data:
(i) How many values arte there in queue?
(ii) If five valuesare deleted,whatwould be the new value of Front?

• 2)

How wil you know that a linear queue is full?

• 3)

What are the drawbacks of linear queue?

• 4)

Write a Get1From2() function in c++ to transfer the content from two array FIRST[] and SECOND[] to array ALL[].the even places(0,2,4...) of array ALL[] should get the content from the array First[] and odd places (1,3,5,...) of the array ALL[] should get the content from the array SECOND[].
e.g if the FIRST[]array contain
30,60,90
and the SECOND[] array contains
10,50,80
The ALL[] array should contain
30,10,60,50,90,80

• 5)

Write a function in c++, with accept an integer array and its size as parameters and replace the elements having odd values with the thrice its value and the element having even with twice its values.

e.g.If an array contains the elements as 3,4,5,16,9. then the function should rearrange the array as 9,8,15,32,27

#### Data File Handling In C++ - Important Questions Model Paper In 12th Computer Science - by KARTHIK S M Jul 30, 2018 - View & Download

• 1)

Write a function COUT_TO() in C++ to cout the presence of aworld 'to' in text file NOTES.TXT is as it is very important to know that smoking is injurious to health,let us take initiative to stop it.The function COUT_TO()will display the following message cout of-to=in file:3

• 2)

Write a function EUCout() in C++,which should reads each character of a a text file.IMP.TXT,should count and display the occurrence of
alphabets E and U (including small case e and u too). e.g. if the file contain is as follows: Update information is simplified by official websites.The EUCount() function should display the output as:
E:4
U:1

• 3)

Write the function in C++ to read the content of a text file PLACES.TXT and display all those lines on screen,which are either starting with'P' or starting with'S'

• 4)

Assuming the class GAMES as declard below, write a function in C++ to read the objects of GAMES from binary file GAMES.DAT and
display those details of those GAMES, which are meant for children of Age Range"8 to 13"
class GAMES
{
int Gamecode;
char GameName[10];
char *AgeRange;
public:
void Enter()
{
cin>>GameCode;
gets(GameName);
gets(AgeRange);
}
void Display()
{
cout<cout<        }
char *AgeR() {return AgeRange;}
};

• 5)

Write a function in C++ to search for the details(phone no and Calls) of those phons, which have more than 1000 calls from a binary file phons.dat. Assuming that this binary file contains records? objects of class phone, which is defined below.
class phone
{
char phoneno[10];
int calls;
public:
void get(){gets(phoneno);
cin>>calls;
void billing(){cout<<int getCalls(){return calls;}
};

#### Object Oriented Programming In C++ - Important Questions Model Paper In 12th Computer Science - by KARTHIK S M Jul 27, 2018 - View & Download

• 1)

How are the object's behaviour and object's characteristics represented in OOP?

• 2)

• 3)

• 4)

Is this possible to declare two functions with same name and same argument but different return type in C++?

• 5)

How are abstraction and encapulation interrelated?

#### Review Of C++ - Important Questions Model Paper In 12th Computer Science - by KARTHIK S M Jul 27, 2018 - View & Download

• 1)

Generally there are four data types, each of which can be signed or unsigned.Write names of all four data types.

• 2)

Give the output of the following program:
int a=44;
cout<<a++<<"\t"<<a<<"\n"<<++a;
cout<<endl<<a<<endl;

• 3)

How 'I' operator is different from '%' operator?

• 4)

Write the difference between = and ==

• 5)

If v is an identifier of int type and is holding value 255. Is the following statement correct?
char code = v;

### CBSE Education Study Materials

#### 12th CBSE Computer Science 2019 - 2020 Academic Syllabus Ekta Bhalla - Kottayam Aug 21, 2019

Computer Science 2019 - 2020 Academic Syllabus

#### Tips by Experts to score full marks in CBSE Class 12 Computer Science KARTHIK S M Jan 24, 2019

CS is a fairly easy subject, you have very less to study and prepare. If you have been consi...

#### Useful Tips to score full marks in CBSE Class 12 Computer Science KARTHIK S M Jan 24, 2019

Computer Science is an important subject which has a lot scope and career opportunities with high...

#### CBSEStudy Material - Sample Question Papers with Solutions for Class 12 Session 2019 - 2020

Latest Sample Question Papers & Study Material for class 12 session 2019 - 2020 for Subjects Biology, Physics, Maths, Chemistry, Accountancy, Business Studies, Economics, Introductory Microeconomics and Macroeconomics in PDF form to free download for practice. Download QB365 Free Mobile app & get practice question papers.

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