CBSE Sample Papers for Class 12 Informatics Practices Paper 3 are part of CBSE Sample Papers for Class 12 Informatics Practices. Here we have given CBSE Sample Papers for Class 12 Informatics Practices Paper 3.

CBSE Sample Papers for Class 12 Informatics Practices Paper 3

Board CBSE
Class XII
Subject Informatics Practices
Sample Paper Set Paper 3
Category CBSE Sample Papers

Students who are going to appear for CBSE Class 12 Examinations are advised to practice the CBSE sample papers given here which is designed as per the latest Syllabus and marking scheme, as prescribed by the CBSE, is given here. Paper 3 of Solved CBSE Sample Paper for Class 12 Informatics Practices is given below with free PDF download solutions.

Time : 3 hrs
Maximum Marks : 70

General Instructions

  • All questions are compulsory.
  • Answer the questions after carefully reading the text.


Question 1.
(a) Name any two transmission medium for networking.
(b) How would you extract Manufacturer_Id and Card_No from a MAC address?
(c) What is the geological scope of LAN, MAN, and WAN?
(d) In how many ways can you type Indian scripts on a computer?
(e) Identify the type of topology from the following:
(i) In it, each node is connected with the help of a single coaxial cable.
(ii) In it, each node is connected with the help of independent cable and central switching (communication controller) node.
(f) Which of the following are open standards and which are proprietary standards?
(i) OGG
(ii) WMA
(iii) DOC
(iv) JPEG
(g) Repeaters are used over long network lines. Explain.

Question 2.
(a) Samarth created a program. He wants that variables used in the class can only be accessed by class’s subclass and not by unrelated classes. Help him by providing the solution.
(b) Write the output in jTextFieldl if stucode is 70.

case 30 :
Mark = 80;
break ; 
case 50 :
Mark = 40 ;
break ;
default :
Mark = 10 ;
j TextFieldl.set Text ("'+Mark) ;

(c) (i) Identify the error(s) in the following HTML code. Also, write the correct code.

<BODY color="yellow" text="white">

(ii) Consider the following XML document. Check this for well-formedness.


(d) What will be the content of the jTextAreal after executing the following code (assuming that the j TextAreal had no content before executing this code)?

for (int i=1;i<=4; i++)
j TextAreal.setText ( j TextAreal.getText ()+" "
+Integer. toString (i  + i )) ;

(e) (i) Rewrite the following code using SWITCH statement :

if (test = = 1)
System.out.println("Hello") ;
else if(test==2)
System.out.println("Hi i") ; 
else if(test= =3)
System.out.print1n("Good") ; 
System.out.println("No Match Found") ;

(ii) Write a method in Java that takes two numbers as input from two text fields and display which is greater in another text field.

Question 3.
(a) A table named OFFICE has 6 rows and 10 columns and another table named STAFF has 3 rows and 5 columns. How many rows and columns will be there if we obtain the Cartesian product of these two tables?
(b) Give one difference between CEIL ( ) and FLOOR ( ) functions.
(c) Explain the use of UNIQUE constraint. How is it different from primary key constraint?
(d) Consider the table ‘COMPANY’.
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 1
(e) (i) Aryan a student of class XII created a table ANNUAL. Grade is one of the column of this table. To find the details of students whose grades have not been entered, he wrote the following MySQL query, which did not give the desired result


Help Aryan to run the query by removing the errors from the query and write the correct query.
(ii) Given below is the ‘STUDENT table:
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 2

What will be the output of the following SQL query now?

Question 4.
(a) Sahil created a program using switch case. He used the data type double for selection variable. Is it correct to define selection variable as double? Give reason.
(b) (i) Consider the following code and given output:

String s1 = new String ("Aryan") ;
String s2 = new String ("Aryan") ; 
if (s1.equals (s2)) .
System.out.println ("si is equal to s2"); 
if (s1 == s2)
System.out.println ("s1 is equal to s2");

(ii) Find out tbe error (s) in the following code fragment:

interface Student 
public void method ( ) ;
public class extends Student
public void method ( ) :

(c) (i) “The variable/expression in the switch statement should either evaluate to an integer value or string value”. State Thie or False.
(ii) Write statement to increase the value assigned to variable K by 2 and then to display the value.
(iii) What will be displayed in jTextAreal after the execution of the following loop? Also, write that how many times this loop will be execute?

for (int K=4; K<=20; K+=4) 
j TextAreal . setText (j TextAreal.getText ( )+" "
+ Integer . to String (2 * K)) ;

(d) Ronit Roy is a programmer at LINC Enterprises. He created the following GUI in NetBeans. Help him to write code for the following:
(i) To display series of odd or even numbers (depending on starting number- j TextField 1 is even or odd) in the j TextArea 1 on click of command button [Display The Series].
e.g. If the start number is 5 and last number is 11.
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 5

Then, TextArea content will be 5 7 9 11. If the start number is 2 and last number is 10. Then, Text Area content will be 2 46 8 10.
(ii) To clear both the text fields and text area, on clicking [Reset] button.
(iii) To terminate the application on the click of [Stop] button.

Question 5.
(a) By using which clause, you can specify a condition to specify the values that you want to view in a particular range?
(b) Table FURNITURE has 7 rows and 10 columns. What is the cardinality and degree of this table?
(c) Explain the following functions and give output of each of the statement.

(i) SELECT INSTR('Computer', ’ P') ; 
(ii) SELECT RIGHT( 'Computer'. 3) ;

(iii) How is left join different from a natural join?

(d) Table “BOOK” is shown below. Write commands in SQL for (i) and (ii) and output for (iii) and (iv)
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 6

(i) Display the Book name, price and page of ‘BOOK table whose author name is Priyanka.
(ii) Display the Book_id and Author_Name of Book whose price above 150.

(iii) SELECT C0UNT(*), Price FROM BOOK WHERE Price = 350 ;
(iv) SELECT SUM(Price) FROM BOOK WHERE Page<200 ;

Question 6.
(a) (i) Create table CUSTOMER as per following Table structure :
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 10
(ii) Consider the following tables PRODUCT and CLIENT :
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 11

I. Which column is used to relate the two tables?
II. Is it possible to have a primary key and a foreign key both in one table? Justify your answer with the help of tables given above.

(b) With reference given to the above tables in Q 6 (a) (ii), write SQL commands for the statements (i) and (ii) and give output for SQL query (iii).
(i) To display the details of products whose Price is in range of 50 to 100 (both values included).
(ii) To display the ClientName, City from table CLIENT and ProductName, Price from table PRODUCT with their corresponding matching P_ID.

(iii) SELECT Manufacturer, MAX(Price), MIN (Price), C0UNT ( * )

Question 7.
(a) How is E-Commerce beneficial to businessmen? Write one point.
(b) What issues are still to be worked out for E-Governance to meet all its objectives?
(c) Ridhi is creating a form for registration of annual function. Help her to choose most appropriate controls out of ListBox, ComboBox, TextField, TextArea, RadioButton, CheckBox and CommandButton for the following entries :
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 13


Answer 1.
(a) Two transmission medium for networking are as follows :
(i) Co-axial cable
(ii) Radiowave

(b) The first three bytes of a MAC address represent Manufacturer Jd and the last three bytes of a MAC address represent Card_No.

(c) LAN is confined to relatively small areas such as a building or a group of buildings.
WAN spans a large area, possibly several continents. MAN is between LAN and WAN,
i.e. spanning a small city or town.

(d) Indian scripts can be entered in two different ways which are as follows:
(i) Using phonetic text entry
(ii) Using keymap based text entry

(e) (i) Bus topology (ii) Star topology

(f) Open Standards (i) OGG and (iv) JPEG
Proprietary Standards (ii) WMA and (iii) DOC

(g) When the transmitted data has to travel over a long distance, the signals start degrading after a certain distance. If the signals degrade too much, the data will be lost and it will fail to reach the destination. Therefore, repeaters are used. Repeater is a device that is used to replicate and amplify a signal over long distance transmission.

Answer 2.
(a) He should declare those protected in the superclass. Since, by declaring the variables as protected they can only be accessed by the subclasses of that class.

(b) j TextFieldl will contain 10.

(c) (i) color is not an attribute of <BODY> tag. To specify background color of the Web page, we use bgcolor attribute of the <BODY> tag. Correct code is:

<BODY bgcolor = "yellow" text = "white">

(ii) Given XML document is not well-formed, because it has a number of root elements. Whereas an XML document must have only one root element.
(d) j TextArea1 will contain 2 4 6 8

(i) switch(test)
case 1:
System.out.println("Hello") ; 
break ;
case 2 :
break ; 
case 3 :
break ; 
default :
System.out.println ("No Match Found") ;

(ii) public void findGreater ()
int a = Integer . parselnt ( jTextField1 . get Text () ) ; 
int b = Integer . parselnt ( jTextField2 . getText () ) ; 
if (a > b)
j TextField3 . setText ("a is greater") ; 
jTextField3 . setText ("b is greater") ;

Answer 3.
(a) Number of rows = 6 × 3 = 18 and number of columns = 10 + 5 = 15
If we obtain Cartesian product of these two tables, we would get 18 rows and 15 columns.
(b) CEIL ( ) function returns the smallest integer value that is not less than passed numeric expression, while FLOOR ( ) function returns the largest integer value that is not greater than passed numeric expression, e.g.
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 3
(c) The UNIQUE constraint on a column ensures that all values in a column are distinct, i.e. no two tuples/rows can have same value in that particular column. A column having UNIQUE constraint can have NULL (until explicitly mentioned as NOT NULL), whereas column having a PRIMARY KEY constraint, implicitly means that the field is required to be UNIQUE and NOT NULL


(e) (i) The correct query is :


CBSE Sample Papers for Class 12 Informatics Practices Paper 3 4

Answer 4.
(a) No, he cannot use double datatype as selection variable in switch as it is not good for exact comparisons. Generally, int, short, byte, or char are only used as selection variable in switch.

(b) (i) Here, only first, System.out.println will work because equals method compares the content of string object, where = = operator compares reference of string object. So output will be: s1 is equal to s2.
(ii) I. A class cannot extend an interface. It should only implement.
II. Definition of method should be given in class or it should be declared as abstract.

(c) (i) True

(ii) int K ;
K = K + 2 ;
System.out.println(K) ;

(iii) Output
j TextAreal will display = 8 16 24 32 40
Loop will be 5 times execute.

(d) (i) We have to double click at the Display The Series button (jButton 1) and type the following code:

int start = Integer . parselnt ( jTextFieldl.getText( ) ); 
int last = Integer.parselnt ( jTextField2.getText( ) ); 
for( int i=start; i<=last; i=i+2)
jTextAreal.append(" " + i):

(ii) We have to double click at the Reset button (jButton2) and type the following code :

jTextFieldl.setText (" ") ; 
jTextField2.setText(" ") ; 
jTextAreal.setText(" ") ;

(iii) We have to double click at the Stop button (jButton3) and type the following code :
System. exit (0) ;

Answer 5.
(a) BETWEEN clause.
(b) Cardinality = number of rows = 7
Degree = number of columns = 10

(c) (i) lNSTR (str,substr) function is used to return position of first occurrence of substr in str.

SELECT INSTR ('Computer'. 'p') ;

CBSE Sample Papers for Class 12 Informatics Practices Paper 3 7

(ii) RIGHT (str, len) function returns the specified Ten’ number of characters from the right of the string ‘str’.

SELECT RIGHT ('Computer' ,3) ;

CBSE Sample Papers for Class 12 Informatics Practices Paper 3 8

(iii) Left join is a form of join where all the rows(even non-matching ones) from the first table are returned in the result.
Whereas in natural join, the result consists of only the matched rows.


(i) SELECT BName, Price, Page FROM BOOK
WHERE Author_Name = 'Priyanka' :
(ii) SELECT B00K_id, Author_Name FROM BOOK WHERE Price >150 ;

CBSE Sample Papers for Class 12 Informatics Practices Paper 3 9

Answer 6.

CAddress VARCHAR (20),
Pincode INTEGER,
Contact_No VARCHAR(10)
) ;
(i) I. P_ID

II. Yes, it is possible to have primary key and foreign key columns in one table.
Primary key column is used to uniquely identify each record of the table while foreign key column is used to maintain referential integrity.

As in the given table CLIENT, C_lD column is a primary key while P_lD may act as a foreign key.

(ii) SELECT CLIENT. ClientName, CLIENT.City, PRODUCT. ProductName, 
CBSE Sample Papers for Class 12 Informatics Practices Paper 3 12

Answer 7.
(a) E-Commerce advantage is acquisition of new customers and increased sales.

(b) The following issues need to be worked out in order to make E-Governance meet all its objectives:

  1. All the services of Government offices should be made available through online portals.
  2. Awareness programs should be conducted to make people aware about the availability of the services available online.
  3. Efforts should be made to remove E-literacy.
  4. The available technology in terms of hardware, software and broadband services should be made within reach of all the people.

CBSE Sample Papers for Class 12 Informatics Practices Paper 3 14

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