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2nd puc computer science question papers with answers 2020
PART - A
Answer all questions. Each
question carries 1 mark. (10 X 1 = 10)
1) what is a port?
Ans: ports are used to connect external devices like printers, keyboards or scanners to the computer.
2) Which gate is called as inverter gate?
Ans: NOT gate is called as inverter gate.
3) Define root node in a binary tree.
Ans: node at the top of a tree- the one from which all operations on the tree commence.
4) Mention the operator used to access member of a class.
Ans: . (dot) operator is used to access member of a class.
5) How to declare a pointer?
Ans: data_type *variable_name;
6) What is meant by data mining?
Ans: data mining is concerned with the analysis and picking out relevant information.
7) Expand MIME.
Ans: Multipurpose Internet Mail Extensions.
8) Name any one type of UTP cable.
Ans: CAT-1, CAT-2, CAT-3, CAT-4
9) Give an example for web browser
Ans: Internet explorer, Firefox Mozilla, Google Chrome, Netscape Navigator etc.
10) What is web scripting?
Ans: The process of creating and embedding scripts in a web page is known as web scripting.
PART - B
answer any five
questions.each question carries 2 marks. (5 X 2 =10)
11) prove that xy+xy'=x.
Ans: LHS: xy+xy'
=x(y+y')
=x.1
=x
12) What is tautology and fallacy?
Ans: if the result of any logical statement is always TRUE is called Tautology and if the result is always FALSE is called Fallacy.
13) Define polymorphism. Give an example.
Ex: int addition(int a, int b)
int addition( float a, float b)
Consider the addition operation. In addition of two numbers the result is the sum of two numbers.
In addition of two strings the operation is string concatenation. When an operator behaves differently based on operands, then it is said that operator is overloaded. Similarly when same function is used for multiple tasks in the same program by changing argument type and number, it is known as function overloading.
PART - C
answer any five questions. Each question carries 3 marks. (5 X 3 = 15)19) define cache memory. Mention the types of cache memory.
Ans: The cache memory is a very high speed memory placed in between RAM and CPU. Cache memory stores data that is used more often, temporarily and makes it available to CPU at a fast rate. During processing, the CPU first checks cache for the required data. If data is not found in cache, then it looks in the RAM for data.
Cache memory is very expensive, so it is smaller in size. Computers have cache memory of sizes 256 KB to 2 MB
Cache memory is built into the processor and may also be located next to it on a separate chip between CPU and RAM. Cache built into CPU is faster than separate cache almost at the speed of the microprocessor itself. However separate cache is roughly twice as fast as RAM. The CPU has a built –in level 1(L1) cache and level2 (L2) cache high end processor nowadays comes with built-in L3 cache, processor like Intel Core i7
|
Mode |
Explanation |
|
ios :: in |
Open a file for reading |
|
ios :: out |
Open a file for writing |
|
ios :: app |
Appends data to the end of the file |
|
ios :: ate |
File
pointer moves to the end of the file but allows to writes data |
Ans:
1) Entity: An entity may be any object, place, or person. In E-R diagram an entity is represented using rectangles.
Weak entity: it depends on another entity. It represented as double rectangle
2) Attribute: An attribute describes a property or characteristic of an entity. For example, name, age, address etc. can attributes of employee. An attribute is represented using ellipse.
PART - D
answer any seven questions. Each
question carries 5 marks. (7 X 5 =35)
27) given Boolean function F(A,B,C,D)=∑(0,1,2,3,6,10,13,14,15) reduce it by
using Karnaugh map.
Ans:
28) write an algorithm to search an element in an array using linear search
method.
Ans:
step 1: LOC=-1
step 2: for P=0 to N-1
if(A[P]=ELE)
LOC=P
GOTO 3
end of if
end of for
step 3: if(LOC>=0)
PRINT LOC
else
PRINT "Search is unsuccessful"
step 4: exit
29) explain different operations on linked list.
Ans:
operations on linked list:
Creating a linked list: linked list is a linear data structure which contains a group of nodes and the nodes are sequentially arranged. nodes are composed of data and address of the next node or reference of the next node.the pointer START contains the location of the first node. Also the next pointer field of the last node must be assigned to NULL. Elements can be inserted anywhere in the linked list and any node can be deleted.
struct Node
{
int data;
Node *link;
};
Node *node1, *node2;
here data is the information field and link is the link field. the link field contains a pointer variable that refers the same node structure. such a reference is called as self referencing pointer.
Traversing a linked list:
Traversing is the process of accessing each node of the linked list exactly once to perform some operation.
Algorithm:
step 1: p=START
step 2: while p=NULL
PROCESS data(p)
p=lik(p)
end of while
step3: return
30) give the differences between procedural programming and object oriented programming.
Ans:
31) write the general syntax for defining and declaring a class with programming example.
Ans:
A class definition is a process of naming a class, data and functions of the class.
A class declaration specifies, representing objects and functions that operate on objects.
The definition and declaration of a class includes the following
- The data members of the class describes the characteristics of the class
- The function members are the set of operations that are performed on the objects of the class.
- The access control specifiers (private, protected and public) to the class members within a program are specified
- Class name is used for external operations for accessing and manipulating the instance of a class
Syntax of a class:
class class_name
{
private: data member;
function member;
protected: data member;
function member;
public: data member;
function member;
};
Example:
class student
{
private: int rollno;
char name[15];
float percentage;
public: void getdata();
void putdata();
};
32) what is function overloading? Explain the needs for function overloading.
Ans: function overloading means two or more functions have same name, but differ in the number of arguments or data type of arguments. Therefore, it is said that function name is overloaded. The advantages of overloaded functions are:
- When functions are overloaded, then the compiler automatically decides and executes appropriate function based on type of arguments and calls the required function. Thus the code is executed faster
- It is easier to understand the flow of information and debug
- Code maintenance is easy
- Easier interface between programs and real world objects
33) what is a constructor? Write the syntax and programming example for default
constructor.
Ans: Constructor is a special member function used to initialize the data members of the class.
Syntax:
class_name calss_name()
{
}
Example:
#include<iostream.h>
#include<conio.h>
class c
{
int a,b;
public: c()
{
a=10;
b=20;
}
void display()
{
cout<<a<<b;
}
};
void main()
{
c obj;
obj.display();
getch();
}
34) what are the advantages of inheritance in C++?
Ans:
- Reusing existing code
- Faster development time
- Easy to maintain
- Easy to extend
- Memory utilization
35) explain the features of database system.
Ans: in the database approach, the data is stored at a central location and is shared among multiple users. Thus, the main advantage of DBMS is centralized data management. The advantages of centralized database system are as follows:
- Controlled data redundancy: elimination of duplication of data item in different files ensures consistency and saves the storage space. The redundancy in the database cannot be eliminated completely as there could be some performance and technical reasons for having some amount of redundancy.
- Enforcing data integrity: data integrity refers to the validity of data and it can be compromised in a number of ways.
- Data sharing: the data stored in the database can be shared among multiple users or application programs. It is possible to satisfy the data requirements of the new applications without creating any additional data or with minimal modification.
- Ease of application development: the application programmer needs to develop the application programs according to user’s needs. The other issues like concurrent access, security, data integrity etc are handled by the RDBMS itself.
- Data security: since the data is stored centrally data security checks can be carried out whenever access is attempted to sensitive data. To ensure security, a RDBMS provides security tools such as used codes and passwords. Different checks can be established for each type of access like addition, modification, deletion etc to each piece of information in the database.
- Multiple user interfaces: For various users having different technical knowledge DBMS provides different types of interfaces such as query languages, application program interfaces, and graphical user interfaces (GUI).
- Backup and recovery: RDBMS provides backup and recovery subsystem that is responsible for recovery from hardware and software failures. For example, if the failure occurs in between the transaction, the RDBMS recovery subsystem either reverts back the database to the state to the previous state of the transaction or resumes the transaction from the point it was interrupted so that its complete effect can be recorded in the database.
36) explain the various group functions in SQL.
Ans:
i) count(): this function returns the number of rows that satisfies a condition written in WHERE clause.
Example:
a) select count(*) from employee;
b) select count(*) from employee where dept=’computer science’;
i) max(): this function returns the maximum value from the column.
Ex: select max(salary) from employee;
ii) min(): this function returns the minimum value from the column.
Ex: select min(salary) from employee;
iii) avg(): this function returns the average value of a numeric column.
Ex: select avg(salary) from employee;
iv) sum(): this function returns the sum of a numeric column.
Ex: select sum(salary) from employee;
37) Give the measures for preventing virus.
Ans:
- Never use a foreign disk or CD without scanning it for viruses.
- Always scan files downloaded from the internet or other sources.
- Write protect your disks.
- Use licensed software.
- Password protect your PC to prevent unauthorized access.
- Install and use antivirus software.
- Keep antivirus software up to date.
2nd puc computer science previous year question papers with answers,2nd puc computer science question papers with answers 2020,2nd puc computer science answer key 2020,2nd puc computer science question papers with answers,2nd puc computer science key answer 2020
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September 24, 2020
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