Students must start practicing the questions from CBSE Sample Papers for Class 12 Informatics Practices with Solutions Set 10 are designed as per the revised syllabus.
CBSE Sample Papers for Class 12 Informatics Practices Set 10 with Solutions
Time Allowed: 3 hours
Maximum Marks: 70
General Instructions:
- This question paper contains five sections, Section A to E.
- All questions are compulsory.
- Section A have 18 questions carrying 01 mark each.
- Section B has 07 Very Short Answer type questions carrying 02 marks each.
- Section C has 05 Short Answer type questions carrying 03 marks each.
- Section D has 03 Long Answer type questions carrying 05 marks each.
- Section E has 02 questions carrying 04 marks each. One internal choice is given in Q35 against part c only.
- All programming questions are to be answered using Python Language only.
Section – A
Multiple Choice Questions
Question 1.
Which of the following indexing capabilities is used as a concise means of selecting data from a pandas object?
(A) In
(B) ix
(C) ipy
(D) iy [1]
Answer:
(B) ix
Explanation: ix attribute is primarily label location based indexer, with integer position fallback. It is used as a concise means of selecting data from a pandas object. [1]
Question 2.
What will be syntax for pandas dataframe?
(A) pandas.DataFrame( data, index, dtype, copy)
(B) pandas.DataFrame( data, index, rows, dtype, copy)
(C) pandas_DataFrame( data, index, columns, dtype, copy)
(D) pandas.DataFrame( data, index, columns, dtype, copy) [1]
Answer:
(D) pandas.DataFrame( data, index, columns, dtype, copy)
Explanation: Pandas DataFrame is two-dimensional size-mutable, potentially heterogeneous tabular data structure with labeled axes (rows and columns). [1]
3. plot( ) is used to create ______
(A) line chart
(B) bar chart
(C) pie chart
(D) histogram [1]
Answer:
(A) line chart
Explanation: The plot( ) function is used to draw points (markers) in a diagram. By default, the plot) function draws a line from point to point. [1]
Question 4.
Which of the following is not a network topology?
(A) Star
(B) Mesh
(C) Tree
(D) Gateway [1]
Answer:
(D) Gateway
Explanation: A gateway is a network device used in telecommunications that connects two networks with different transmission protocols together. Gateways serve as an entry and exit point for a network as all data must pass through or communicate with the gateway prior to being routed. [1]
Question 5.
Which topology in general uses less wire length compare to other ?
(A) Star Topology
(B) Ring Topology
(C) Bus Topology
(D) All use same Length of Wire [1]
Answer:
(C) Bus Topology
Explanation: A bus topology is a topology for a Local Area Network (LAN) in which all the nodes are connected to a single cable. The cable to which the nodes connect is called a “backbone”. If the backbone is broken, the entire segment fails. [1]
Question 6.
Intellectual property is legally protected by:
(A) copyright
(B) patents
(C) trademarks
(D) all of these [1]
Answer:
(D) all of these
Explanation: Intellectual Property (IP) is protected in law by, for example, patents, copyright and trademarks, which enable people to earn recognition or financial benefit from what they invent or create. [1]
Question 7.
The following cannot be exploited by assigning or by licensing the rights to others.
(A) Patents
(B) Designs
(C) Trademark
(D) All of the above [1]
Answer:
(C) Trademark
Explanation: A trademark is a sign capable of distinguishing the goods or services of one enterprise from those of other enterprises. [1]
Question 8.
Write the output of the following SQL command. SELECT SUBSTR(“WORLD”,2,3);
(A) ORL
(B) WO
(C) WOR
(D) LD [1]
Answer:
(A) ORL
Explanation: The SUBSTRO function extracts some characters from a stringSyntax SUBSTR(string, start, length) [1]
Question 9.
What is the result of the following? SELECT MOD (75,8);
(A) 1
(B) 2
(C) 3
(D) 4 [1]
Answer:
(C) 3
Explanation: SQL MODO function is used to get the remainder from a division. [1]
Commonly Made Error:
Sometime students base number as exponent and exponent as base number in Power function and dividend as divider and divider as dividend in Mod function
Answering Tip:
Students should remember that first argument is base value and second argument as exponent value in power function and in Mod function, first argument represents dividend and second argument represents divider.
Question 10.
Write the output of the following SQL query SELECT POW (INSTR(‘Wonders’,’n’),3);
(A) 12
(B) 9
(C) 16
(D) 25 [1]
Answer:
(B) 9
Explanation: INSTR( ) is a string function in standard query language (SQL) which returns the starting position or location of a substring or pattern in the given input string. [1]
Question 11.
Which of the following digital footprints can be created without the user’s consent?
(A) Active digital footprint
(B) Passive digital footprint
(C) Massive digital footprint
(D) Interactive digital footprint [1]
Answer:
(B) Passive digital footprint
Explanation: A passive digital footprint is a data trail you unintentionally leave online. [1]
Question 12.
It is OK to forward or post an email message that you received if:
(A) the message is typed in all capitals.
(B) the author of the message has given you permission to forward or post it.
(C) it does not contain any copyrighted material.
(D) the author of the message hasn’t marked it as confidential. [1]
Answer:
(B) the author of the message has given you permission to forward or post it. [1]
Question 13.
F’in FOSS stands for:
(A) Free
(B) Forever
(C) Fire
(D) Freezing [1]
Answer:
(A) Free
Explanation: Free and open-source software (FOSS) is software that can be classified as both free software and open-source software. [1]
Question 14.
Which type of values will not be considered by SQL while executing the following statement? SELECT COUNT(column name) FROM Student;
(A) Null value
(B) Integer value
(C) Name value
(D) Address value [1]
Answer:
(A) Null value
Explanation: The COUNT( ) function returns the number of records returned by a select query. Note: NULL values are not counted. Syntax COUNT(expression) [1]
Question 15.
If column “Marks” contains the data set (500,800,750,500,800), what will be the output after the execution of the given query? SELECT MAX (DISTINCT Fees) FROM College;
(A) 750
(B) 800
(C) 500
(D) Error [1]
Answer:
(B) 800
Explanation: DISTINCT statement is used to return only distinct (different) values. [1]
Question 16.
Find the output of: SELECT LEFT (‘Schooľ, 2);
(A) SC
(B) ch
(C) ol
(D) Sch [1]
Answer:
(A) SC
Explanation: LEFTO is used to return a specified number of characters from the left of the string. The number of characters returned is determined by the second argument. [1]
Assertion & Reason
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice’as: (A) Both assertion
(A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(B) Both assertion (A) and reason (R) are true but reason (R) is NOT the correct explanation of assertion (A).
(C) Assertion (A) is true but reason (R) is false.
(D) Assertion (A) is false but reason (R) is true.
Question 17.
Assertion (A): SMTP stands for Simple Mail Transfer Protocol.
Reason (R): SMTP is the standard protocol for sending emails across the Internet.
Answer:
(A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
Explanation: SMTP is used to send and receive email. It is sometimes paired with IMAP or POP3 (for example, by a user-level application), which handles the retrieval of messages, while SMTP primarily sends messages to a server for forwarding. [1]
Question 18.
Assertion (A): The axis labels are collectively called index.
Reason (R): Pandas Series is nothing but a column in an excel sheet.
Answer:
(B) Both assertion (A) and reason (R) are true but reason (R) is NOT the correct explanation of assertion (A).
Explanation: Pandas Series is a one dimensional labeled array capable of holding data of any type (integer, string, float, python objects, etc.). The axis labels are collectively called index. Pandas Series is nothing but a column in an excel sheet. [1]
Section – B
Question 19.
Distinguish between web browser and web server.
OR
Priyanka, a beginner in IT field has just started learning web technologies. Help her in understanding the difference between website and web pages with the help of a suitable general example of each.
Answer:
Difference between web browser and web server are as follows: [2]
| Web browser | Web server |
| It requests the server for the web documents and services. | Web server accepts, approve and respond to the request made by the web browser for a web document or services. |
| The web browser sends an HTTP request and gets an HTTP response. | The web server gets HTTP requests and sends HTTP responses. |
OR
The difference between a website and a web page is that a website is a collection of different web pages containing information on a particular topic. A web page is an individual page of a big website usually containing more specific information. If we compare a website with a book, then a webpage can be compared with a single page of that book.
Question 20.
Explain the MOD( ) functions with an example. [2]
Answer:
MOD( ) function is used to return the remainder of one expression by dividing it by another expression.
Syntax
MOD (nm)
e.g.
SELECT MOD(20,3);
Ouput
2 [2]
Question 21.
Consider the following SQL string: “Shutterstock” Write commands to display:
(a) “stock”
(b) “ter” [2]
Answer:
(a) SELECT MID (“Shutterstock”, 8);
(b) SELECT SUBSTR(“Shutterstock”,5,3);
Question 22.
Give the output: import pandas as pd
data = [[‘Alex’, 10], [ ‘Bob’, 12], [‘Claske’, 13]]
df = pd. DataFrame (data, columns = [ ‘Name’,’Age’])
print (df)
Answer:
Output
| – | Name | Age |
| 0 | Alex | 10 |
| 1 | Bob | 12 |
| 2 | Claske | 13 |
Question 23.
Write examples of identity theft.
OR
What do you mean by copyright ?
Answer:
(i) Financial identity theft: When the stolen identity is used for financial gain.
(ii) Criminal identity theft: Criminals use a victim’s Stolen identity to avoid detection of their true identity.
(iii) Medical identity theft: Criminals can seek medical drugs or treatments using a stolen identity. [2]
OR
It grants legal rights to creators and authors. Copyright law gives the copyright holder a set of rights, that they alone can avail legally. The rights include right to copy (reproduce) a work, right to create derivative Works based upon it, right to distribute copies of the work to the public and right to publicly display or perform the work. It prevents others from copying, using or selling the work. [2]
Question 24.
Differentiate between Series data structure and Dataframe data structure?
Answer:
A series is one dimensional object that can hold any data type such as integers, floats, and strings. It has only one axis. A DataFrame is two dimensional object that can hold different data types. Individual columns of a Dataframe can act as an separate series object. [2]
Question 25.
Consider a given series, M1:
Write a program in Python Pandas to create the series.
Answer:
import pandas as pd
Mi = pd. Series 45, 65, 24, 89), index = [‘Terml’, “Term2′, ‘Term3’, ‘Term4’])
print(MI) [2]
Section – C
Question 26.
Given SchoolBus table as follows
| Rtna | Area_Covered | Capacity | Noofstudents | Distance | Transporter | Charges |
| 1. | Vasant Kunj | 100 | 120 | 10 | Shivam Travels | 100000 |
| 2. | Hauz Khas | 80 | 80 | 10 | Anand Travels | 85000 |
| 3. | Patampura | 60 | 55 | 30 | Anand Travels | 60000 |
| 4. | Rohini | 100 | 90 | 35 | Anand Travels | 100000 |
| 5. | Yamuna Vihar | 50 | 60 | 20 | Bhalla Travels | 55000 |
| 6. | Krishna Nagar | 70 | 80 | 30 | Yadav Travels | 80000 |
| 7. | Vasundhara | 100 | 110 | 20 | Yadav Travels | 100000 |
| 8. | Paschim Vihar | 40 | 40 | 20 | Speed Travels | 55000 |
| 9. | Saket | 120 | 120 | 10 | Kisan Tours | 100000 |
| 10. | Janakpuri | 100 | 100 | 20 | Transporter | 95000 |
What values will the following statements return?
(a) select sum(Distance) from SchoolBus where Transporter=“Yadav travels”;
(b) select min(Noofstudents) from SchoolBus;
(c) select avg(Charges) from SchoolBus where Transporter=”Anand travels”;
Answer:
(i) 50
(ii) 40
(iii) 81666.66 [3]
Question 27.
How to import pandas library?
Answer:
Importing pandas library:
You need to import or load the Pandas library first in order to use it. By “Importing a library, it means loading it into the memory and then you can use it. Run the following code to import pandas library: import pandas as pd The “pd” is an alias or abbreviation which will be used as a shortcut to access or call pandas functions. To access the functions from pandas library, you just need to type pd.function instead of pandas, function every time you need to apply it. [3]
Question 28.
In a Dataframe how will you change:
(i) a column
(ii) a row
(iii) an individual data value
Answer:
(i) To change a column use syntax.
<dataframe> [<columnname>] = <new value>
(ii) To change a row, use syntax
<dataframe>.[<rowname>, <new value>
(iii) To change an individual data value use syntax: ,
<dataframe> <columnname> (<row name/ label>] = <newvalue> [3]
Commonly Made Error:
Sometimes Students get confused in programming syntax.
Answering Tip:
Student should learn the proper syntax of programming.
Question 29.
What is software license? Also write its types.
OR
How technology affects the following things:
(i) Eyes strain
(ii) Sleep disorders
(iii) Physical inactivity
Answer:
Software license is a document that provides legally binding guidelines for the use and distribution of software Software licenses typically provide end users with the right to create one or more copies of the software without violating copy rights.
Types of software license
(i) Proprietary license is a license where the copyright stays with the producer and the user is granted the right to use the software.
(ii) GNU General Public License (GPL) are agreements under which open source software usually licensed
(iii) End User License Agreement (EULA) indicates the terms under which the end user may use the software.
(iv) Creative commons (CC) License is a public copyright license that enables free distribution of a copyrighted work.[3]
OR
(i) Eyes strain: When we gaze at a screen for long periods of time, we often forget to blink. In fact, research has shown that digital eye strain reduces our blink rate by half, which means the tears that protect our eyes evaporate without being replaced. Additionally, reading the smaller fonts on a smartphone or other portable device can intensify the strain
(ii) Sleep Disorders: We love our devices so much that many of us even sleep with them. One study found that 72% of smartphone owners keep their phone next to their bed at night to ensure they do not miss a thing. It might see like a harmless habit but late night technology use can interfere with your ability to sleep. To avoid sleep disruption, try replacing late night technology use with sleep conducive activities such as taking a bath or reading in bed. Resisting the urge to keep your phone on your nightstand can also help minimize night time interruptions.
(iii) Physical Inactivity: When we are using technology like computers, video games or TVs, we generally are not exercising. That’s why there’s an increasing body of research linking the overuse of digital devices to decreasing exercise and fitness levels. Logically, spending more time on watching TV or playing video games reduces the time you spend staying active. [3]
Question 30.
Name any one single row function and any one aggregate function. Also mention the difference in their working. [3]
OR
Write the output of the following SQL queries :
(i) SELECT INSTR(‘INFORMATION TECHNOLOGY, TECH’);
(ii) SELECT LENGTH(CONCAT(‘HEALTH’, ‘WEALTH’));
(iii) SELECT RIGHT(“PUBLICATION WORLD”,4);
Answer:
Single row function: LENGTH ( )
Aggregate function: MAX( )
A single row function works on every row of a table and hence gives output for each row in the table An aggregate function also known as multiple row function works on a group of rows and returns only one output. [3]
OR
(i) 13
(ii) 12
(iii) ORLD
Commonly Made Error:
Sometime Students execute the nested function from outward to inward direction, that gives wrong output.
Answering Tip:
Students should remember that nested functions always processed from inward to outward direction
Section – D
Question 31.
Which function extracts a given number of characters from the right side of a specified character string? Explain with example. [5]
OR
Consider a table ABC with following fields:
PID
City
Name
Pin_Code
Gender
Basic_salary
Write SQL commands to :
(i) Display the name and city of all the females getting Basic Salary above 40,000.
(ii) Display Name and Basic salary of all the persons whose name starts with ‘G‘.
(iii) Delete the record of those whose pin code is 182141.
(iv) Display PID, City and Pin code of ABC in descending order of pin code.
(v) Identify the primary key from table ABC.
Answer:
The RIGHTO) function extracts a given number of characters from the right side of a specified character string. For example, RIGHT(‘SQL Server’, 6) returns Server.
The syntax of the RIGHT( ) function is as follows: RIGHT (input_string, number of characters ) In this syntax: The input_string can be a literal string variable, or column. The result of the input string can be in any data type, except for TEXT or NTEXT, that is implicitly converted to VARCHAR or NVARCHAR. The number of characters is a positive integer that specifies the number of characters of the input_string will be returned.
Note that the RIGHT ( ) function returns a value of VARCHAR when the input_string is a non-Unicode character data type or NVARCHAR if the input string is a Unicode character data type. The following statement uses RIGHT() to return the three rightmost characters of the character string
SQL Server:
SELECT RIGHT(‘SQL Server”,6) Result_string
Here is the output:
Result_string
…………
Server: [5]
OR
(i) SELECT Name, City FROM ABC WHERE Gender = ‘F and Basic_salary> 40,000;
(ii) SELECT Name, Basic salary FROM ABC WHERE Name LIKE’G%’;
(iii) DELETE FROM ABC WHERE Pin_Code = 182141;
(iv) SELECT PID, City, Pin Code FROM ABC ORDER By Pin Code DESC;
(v) PID [5]
Question 32.
Perfect Edu services Ltd. is as educational organization. It is planning to setup its India campus at Karnataka with its head office at Delhi. The Karnataka 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 (v), keeping in mind the distances between the buildings and other given parameters.
Shortest distances between various buildings :
| Admin to Engineering | 55 mt |
| Admin to Business | 90 mt |
| Admin to Media | 90 mt |
| Engineering to Business | 55 mt |
| Engineering to Media | 90 mt |
| Business to Media | 456 mt |
| Delhi head office to Karnataka Campus | 2175 km |
Number of computers installed at various buildings are a follows:
| Admin
Engineering Business |
110
75 40 |
| Media | 12 |
| Delhi Head Office | 20 |
(i) Suggest the most appropriate location of the server inside the Karnataka campus to get the best connectivity for maximum no. of computers.
(ii) Draw the cable layout to efficiently connect various building with the Karnataka campus for connecting the computers.
(iii) Which hardware device will you suggest to be procured by the company to be installed to protect and control the internet usage within the campus ?
(iv) Which of the following will you suggest to establish the online face to face communication between the people in the admin office Karnataka campus and Delhi Head office
E-mail
Text Chat
Video Conferencing
Cable TV
(v) Suggest a device and protocol that shall be needed to provide wireless Internet access to all smartphone/ laptop users in the Karnataka campus.
Answer:
(i) Admin (Due to maximum number of computers)
(ii) 
(iii) Firewall or router
(iv) Video conferencing
(v) IEEE 802.11 Wi-Fi Router and IEEE 802.11 Wi-Fi Router [5]
Question 33.
Consider a Dataframe study having following data where 1, 2, 3, 4, 5, 6 are index labels that represent Roll Nos. [5]
| RollNo. | Name | Sub1 | Sub2 | Sub3 |
| 1. | Anubhav | 56 | 91 | 63 |
| 2. | Tishya | 39 | 78 | 45 |
| 3. | Arnav | 80 | 33 | 78 |
| 4. | Siddhant | 78 | 42 | 23 |
| 5. | Garvit | 23 | 98 | 43 |
| 6. | Gungun | 38 | 89 | 56 |
(i) Which method is used to delete row from dataFrame?
(ii) Print data type of column sub3.
(iii) Print record of student named ‘Siddhant’.
(iv) Print record of rollnos between 2 and 6(both included).
(v) Print total number of columns.
OR
Write the code for given bar graph
Answer:
(i) drop ( )
(ii) print(df (sub3].dtype)
(iii) print(df'[Name’).str. contains(“Siddhant”))
(iv) print(df.loc(2:7])
(v) print(len(df.columns)) [5]
OR
from matplotlib import pyplot as plt
plt.bar([0.25, 1.25, 2.25, 3.25, 4.25), [50, 40, 70, 80, 20],
label = “Science”, width = 5)
plt.bar((-75, 1.75, 2.75, 3.75, 4.75], [80, 20, 20, 50, 60),
label = “Maths”, color = ‘r’, width = 5)
plt.legend( )
plt.xlabel(‘Months’)
plt.ylabel(‘Subject’)
plt.title(‘Information’)
plt.show( )
commonly Made Error:
Some students are good in theory but not in programming, so they did mistake in coding.
Answering Tip:
Students should practice the program and coding practically so that their concepts could be clear.
Section – E
Case based Subjective Questions
Question 34.
Consider the table EXAM given below.
| No. | Name | Stipend | Subject | Average | Division |
| 1. | Karan | 400 | English | 68 | FIRST |
| 2. | Aman | 680 | Mathematics | 72 | FIRST |
| 3. | Javed | 500 | Accounts | 67 | FIRST |
| 4. | Bishakh | 200 | Informatics | 55 | SECOND |
| 5. | Sugandha | 400 | History | 35 | THIRD |
| 6. | Suparna | 550 | Geography | 45 | THIRD |
(i) To list the names of those students who have obtained DIVISION as FIRST in the ascending order of NAME. [1]
(ii) To count the number of students who have either accounts or informatics as subject. [1]
(iii) SELECT COUNT(DISTINCT Subject) FROM EXAM; [2]
OR (Option for part iii only)
SELECT MIN(Average) from EXAM WHERE Subject=”English”;
Answer:
(i) SELECT Name FROM EXAM WHERE
Division ‘FIRST’ ORDER BY Name ASC [1]
(ii) SELECT COUNT(*) FROM EXAM WHERE
Subject IN (‘Accounts, Informatics’); [1]
(iii) count
6 [2]
OR
MIN (average)
68
Question 35.
Consider the following DataFrame df
| ID | Name | Age | Fav_Color | Points |
| T01 | Rahul Anand | 32 | Blue | 73 |
| T02 | Mohak Girdhar | 25 | Green | 82 |
| T03 | Rajeev Tyagi | 45 | Orange | 29 |
| T04 | Rohini Malik | 30 | Pink | 39 |
(a) Answer the following questions
(i) Write down the command that will add a column “eligible” with default values as ‘yes’.
(ii) Which command will be used to drop a row from dataframe ‘df’ labelled as ‘T04′ ?
(iii) Write the command to extract the complete row “T03′ and also define this command.
OR (Option for part iii only)
Write the statement to list the first three entries of the DataFrame’df’. Also, define this command.
Answer:
(a) (i) df[‘eligible’]=’yes’
(ii) df.drop(‘T04) [1]
(b) df.loc[T03,:)
DataFrame.locl) method is a method that takes only index labels and returns row or dataframe if the index label exists in the caller data frame. [2]
OR
df.head(3)
head(n) is used to get the first n rows of the DataFrame. It takes one optional argument n (number of rows you want to get from the start). By default n = 5, it return first 5 rows if value of n is not passed to the method.
Commonly Made Error:
Some students get confused between Series and Dataframe and they write about Series instead of Dataframe.
Answering Tip:
Students should be clear all definition and their applications.