Students must start practicing the questions from CBSE Sample Papers for Class 12 Informatics Practices with Solutions Set 12 are designed as per the revised syllabus.
CBSE Sample Papers for Class 12 Informatics Practices Set 12 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 has 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 02 questions carrying 04 marks each.
- Section E has 03 questions carrying 05 marks each.
- All programming questions are to be answered using Python Language only.
Section – A
Question 1.
Sumona has invented a new theory in Physics. She wants to protect it legally against unauthorised use. She should take its ____.
(a) Copyright
(b) Patent
(c) Trademark
(d) None
Answer:
(a) Copyright
Question 2.
The trail that is automatically created when a person uses the internet on any digital devices like Laptops, smartphones, tablets, etc is called ____.
(a) Cyberbullying
(b) Phishing
(c) Digital Footprint
(d) Digital Activity
Answer:
(c) Digital Footprint
Question 3.
Given a Pandas series called Sequences, the command which will display the first 4 rows is
(a) print(Sequences.head(4})
(b) print(Sequences.Head (4))
(c) print(Sequences.heads(4))
(d) print(Sequences.Heads (4))
Answer:
(a) print(Sequences.head(4))
Question 4.
Which of the following does not come inside the Creative Common License?
(a) Movie
(b) Image
(c) Book
(d) Software
Answer:
(d) Software
Question 5.
What is the meaning of Remark LIKE “%5%5%”?
(a) Column Remark begin with two 5s
(b) Column Remark ends with two 5s
(c) Column Remark has more than two 5s
(d) Column Remark has two 5s in it, at any position
Answer:
(d) Column Remark has two 5s in it, at any position
Question 6.
Which Python library is not used for data science?
(a) Panda
(b) Numpy
(c) Matplotlib
(d) Tkinter
Answer:
(d) Tkinter
Question 7.
The software which can be used and copied freely but cannot be modified is _____.
(a) Freeware
(b) Shareware
(c) Proprietary software
(d) Open source software
Answer:
(a) Freeware
Question 8.
To change the 5th column’s value at 3rd row as 35 in DataFrame DF, we can write
(a) DF[4, 6] = 35
(b) DF.iat[4, 6] = 35
(c) DF[3, 5] = 35
(d) DF.iat [3, 5] = 35
Answer:
(d) DF.iat[3, 5] = 35
Question 9.
PHP language is used to create ____.
(a) Dynamic Website
(b) Static Website
(c) Both the types of website
(d) It is not a programming language
Answer:
(c) Both the types of website
Question 10.
Consider the following table namely Employee
Employee_id | Name | Salary |
1001 | Misha | 6000 |
1009 | Khushi | 4500 |
1018 | Japneet | 7000 |
Which of the names will not be displayed by the below given query?
SELECT Name FROM Employee WHERE Employee_id>1009;
(a) Misha, Khushi
(b) Khushi, Japneet
(c) Japneet
(d) Misha, Japneet
Answer:
(a) Misha, Khushi
Question 11.
Which is incorrect?
(a) EULA contains do’s and don’ts with respect to the software being purchased.
(b) Copyright protects the idea itself not its form of expression.
(c) Copyright infringement means using creator’s work without his permission or without paying for it.
(d) Using other’s work without giving him/her citation is called plagiarism.
Answer:
(b) Copyright protects the idea itself not its form of expression.
Question 12.
In SQL, which of the following will select only one copy of each set of duplicate rows from a table?
(a) SELECT UNIQUE
(b) SELECT DISTINCT
(c) SELECT DIFFERENT
(d) All of the above
Answer:
(b) SELECT DISTINCT
Question 13.
When the signal from one wire bleeds into another wire, it is called as
(a) Radio waves
(b) Infrared
(c) Laser
(d) None of these
Answer:
(d) None of these
Question 14.
What will be returned by the given query?
SELECT ROUND(153.669.2);
(a) 153.6
(b) 153.66
(c) 153.67
(d) 153.7
Answer:
(c) 153.67
Question 15.
Consider the following SQL statement. What type of statement is this?
INSERT INTO instructor VALUES (10211, ‘SHREYA’, ‘BIOLOGY’, 69000);
(a) Procedure
(b) DML
(c) DCL
(d) DDL
Answer:
(b)DML
Question 16.
Which operator tests a column for the absence of data(i.e. NULL value)?
(a) Exist Operator
(b) NOT Operator
(c) IS Operator
(d) None of the above
Answer:
(c) IS Operator
Question 17.
Assertion (A) In March 1989, Tim Berners-Lee took the initiative towards the invention of WWW and wrote the first proposal for the World Wide Web.
Reason (R) World Wide Web is a way of exchanging information between computers on the Internet.
(a) Both A and R are true and R is the correct explanation for A.
(b) Both A and R are true and R is not the correct explanation for A.
(c) A is true but R is false.
(d) A is false and R is true.
Answer:
(b) Both A and R are true and R is not the correct explanation for A.
Question 18.
Assertion (A) DataFrame is two dimensional data structure which labelled axes i.e. rows and columns.
Reason (R) Columns of DataFrame can be heterogeneous.
(a) Both A and R are true and R is the correct explanation for A.
(b) Both A and R are true and R is not the correct explanation for A.
(c) A is true but R is false.
(d) A is false and R is true.
Answer:
(b) Both A and R are true and R is not the correct explanation for A.
Section – B
Question 19.
What is the difference between STAR and BUS topologies?
Or
What is the deference between the http and https websites?
Answer:
STAR Topology is topology in which all the nodes are connected with central computer. But in Bus topology, a single wire runs across the network and all the nodes are connected to the central bus.
Or
http is the normal HyperText Transfer Protocol but https is the Secured HyperText Transfer Protocol.
Question 20.
Identify the problem/issue with the following SQL query :
SELECT house, COUNT(*) FROM Student;
Answer:
The problem with the given SQL query is that there is no GROUP BY clause is given, and thus it will lead to an error. The reason being that the select list use COUNT() function, which is an aggregate function, along with a field. When we use an aggregate function in the select list along with a database field, we need to add a GROUP BY clause. To correct the error it should use GROUP BY clause.
SELECT house, COUNT(*) FROM Student GROUP BY house;
Question 21.
Consider the following SQL string : ‘Preoccupied’. Write commands to display:
(a) ‘occupied’
(b) ‘cup’
Answer:
(a) SELECT SUBSTR(‘’Preoccupied’, 4);
(b) SELECT SUBSTR(”Preoccupied’, 6, 3);
Question 22.
The python code written below has
syntactical errors. Rewrite the correct code and underline the corrections made.
Import pandas as Pd data = ('A': [1, 2, 3], 'B’: [4, 5, 6]} df = Pd.DataFrame(data) result = df[A] + df[B]
Answer:
import pandas as pd data = {'A': [1, 2, 3], 'B': [4, 5, 6]} df = pd.DataFrame(data) result = df[’A'] + df['B']
Question 23.
What are the primary interest of online attackers in spyware?
Answer:
Primary interest of online attackers in spyware is using it to steal personal information for financial crimes such as carding and identity theft or to sell that information to someone else who, then executes more traditional financial crimes.
Question 24.
Complete the given Python code: to given a DataFrame ‘df’, add a new column ‘Total’ that contains the sum of the ‘Math’ and ‘Science’ columns.
import ____ as pd data = ('Name': ['John', 'Jane', 'Mike', 'Emily'], 'Math': [80, 90, 75, 85], 'Science': [70, 88, 92, 78]) df = pd.DataFrame(____) df ['Total'] = df ['____'] + df ['____'] print(df)
Answer:
import pandas as pd data = {'Name': ['John', 'Jane', ’Mike’, 'Emily'], 'Math': [80, 90, 75, 85], 'Science': [70, 88, 92, 78]} df = pd.DataFrame(data) df['Total'] = df['Math'] + df['Science’] print(df)
Question 25.
Consider the following DataFrame dfn :
Write the output of the following statement.
(i) dfn [[‘A’, ’B’]]
(ii) dfn.loc[‘Purchase’, :]
Answer:
(i)
A | B | |
Order | 450 | 180 |
Purchase | 330 | 550 |
Sell | 250 | 410 |
Target | 1050 | 980 |
(ii)
A | 330 |
B | 550 |
C | 610 |
Question 26.
A relation Vehicles is given below:
Vno | Type | Company | Price | Qty |
AW125 | Wagon | Maruti | 250000 | 25 |
J0083 | Jeep | Mahindra | 4000000 | 15 |
S9090 | SUV | Mitsubishi | 2500000 | 18 |
M0892 | Mini van | Datsun | 1500000 | 26 |
W9760 | SUV | Meruti | 2500000 | 18 |
R2409 | Mini van | Mahindra | 350000 | 15 |
Write SQL Commands to:
(i) Display the average price of each type of vehicle having quantity more than 20.
(ii) Count the type of vehicles manufactured by each company.
(iii) Display the total price of all the types of vehicles.
Or
Write SQL queries for (i) to (iii), which are based on the following table PARTICIPANTS:
PNO | EVENT | SNAME | CLASS | DOB |
P1 | DEBATE | SANYAM | 12 | 2001-12-25 |
P2 | DEBATE | SHRUTI | 10 | 2003-11-10 |
P3 | DEBATE | MEHER | 12 | 2001-11-10 |
P4 | QUIZ | SAKSHI | 11 | 2002-10-12 |
P5 | QUIZ | RITESH | 12 | 2001-10-12 |
P6 | QUIZ | RAHUL | 10 | 2003-10-12 |
P7 | CROSSWORD | AMEER | 11 | 2002-05-09 |
P8 | CROSSWORD | MINAKSHI | 12 | 2001-05-09 |
(i) To display details of all PARTICIPANTS of class 10 and 12.
(ii) To display the SNAME and Class of all PARTICIPANTS in ascending order of their SNAME.
(iii) To display the number of PARTICIPANTS along with their respective CLASS, of every CLASS.
Answer:
(i) SELECT Type, AVG(Price) FROM Vehicle GROUP BY Type HAVING Qty>20;
(ii) SELECT Company, COUNT(DISTINCT Type) FROM Vehicle GROUP BY Company;
(iii) SELECT Type, SUM(Price*Qty) FROM Vehicle GROUP BY Type;
Or
(i) SELECT * FROM PARTICIPANTS WHERE CLASS IN(10,12);
(ii) SELECT SNAME, CLASS FROM PARTICIPANTS ORDER BY SNAME;
(iii) SELECT COUNT(*), CLASS FROM PARTICIPANTS GROUP BY CLASS;
Question 27.
Give an example to create a DataFrame from the list of dictionary. Also, display its output.
Answer:
import pandas as pd A = {‘0ne’:23, 'Two-, 44, 'Three': 54, ‘Four’ : 77) B = (‘One’ : 44, ‘Two’ : 75, ‘Three’ : 89, ‘Four’ : 29) C = (‘One’ : 29, ‘Two’ : 52, ‘Three’ : 63, ‘Four’ : 38) D = (‘One’ : 12, ‘Two’ : 42, ‘Three’ : 7, ‘Four’ : 16) data = [A, B, C, D] df=pd.Data Frame(data) print(df)
Question 28.
Consider the following DataFrame dfn that contain vegetables.
Color | Quantity | Price | |
Capsicum | Red | 12 | 60 |
Capsicum | Green | 22 | 100 |
Chfilli | Red | 50 | 40 |
Chilli | Green | 65 | 55 |
Lime | Green | 20 | 35 |
Write the code statement to the following:
(i) Find all rows with the label “Chilli”. Extract all columns.
(ii) List 2nd, 3rd and 4th rows.
(iii) List only the columns Quantity and Price using loc.
Answer:
(i) dfn.loc[‘Chilli’, :]
(ii) dfn.iloc[0:3, :]
(iii) dfn.loc[: , [‘Quantity’, ‘Price’]]
Question 29.
List any three guidelines to avoid plagiarism.
Or
What are the disadvantages of E-waste recycling?
Answer:
- IT Act 2000 is not applicable on the attestation for making will of any body.
- Attestation for giving power of attorney of property is not possible via electronic record.
- A contract of sale of any immovable property.
Or
Disadvantages of E-waste recycling are as follows
(i) More Pollution and Energy Consumption
It’s contradicting, but the reality is that recycling tons of garbage will require waste to be transported, sorted, cleaned and processed in separate factories, all of which need energy and may result in by-products that can pollute air, water or soil when more trucks are employed to pick up recyclable products.
(ii) Good Products are not Guaranteed
Not all recycled items are of high quality or even safe to use. As previously mentioned, recycled products may contain toxic chemicals that were previously present with the original material.
Question 30.
Reena is working with functions of MySQL. Explain her following:
(i) What is the purpose of NOW( ) function?
(ii) How many parameters does it accept?
(iii) What is the general format of its return type?
Answer:
(i) The NOW( function returns the system date and time.
(ii) 0 parameters
(iii) “YYYY-MM-DD HH: MM : SS”
Section – D
Question 31.
Consider the following table CLUB.
COACH_ID | COACH NAME | AGE | SPORTS | Date_of_Joining | PAY |
1 | Rajesh | 30 | Karate | 1999-08-25 | 1000 |
2 | Anuj | 35 | Swimming | 2000-01-05 | 750 |
3 | Shuchi | 25 | Basketball | 2005-01-04 | 1200 |
4 | Reetika | 28 | Badminton | 2002-08-25 | 1400 |
5 | Virendra | 32 | Cricket | 1996-05-17 | 1500 |
Give the answer of the following questions
on the basis of the above table.
(i) Write a query to display the substring of 4 characters of the name of each coach, starting from second character, with their age.
(ii) What will be the output of the following query?
mysql>SELECT CONCAT(COACHNAME,AGE) FROM CLUB WHERE AGE > 30;
(iii) Write a query to display the day for the Date_of_Joining column.
(iv) What will be the output of the following query?
mysql > SELECT PAY *0.25+1000
FROM CLUB
WHERE COACHNAME LIKE ‘R%’;
Answer:
(i) mysql >SELECT SUBSTR (C0ACHNAME, 2, 4), AGE FROM CLUB;
(ii)
(iii) mysql >SELECT DAY (Date_of Joining);
(iv)
Question 32.
Write one Python program to find the following from the given DataFrame DF:
Rollno | Name | Age | Marks |
1 | Arun | 18 | 68 |
2 | Mohit | 14 | 47 |
3 | Karan | 13 | 78 |
4 | Lai it | 16 | 87 |
5 | Ravi | 14 | 60 |
(i) Write the statement to display
(a) Maximum marks
(b) minimum marks
(ii) Sum of all the marks
(iii) Mean and mode of age of the students
Or
(Option for part (iii) only)
Count the number of rows present in the DataFrame.
Answer:
(i) (a) print(“Maximum marks =”, DF[“Marks”], max() )
(b) print(“Minimum marks =”, DF[“Marks”].min() )
(ii) print(“Sum of marks =”, DF[“Marks”].sum() )
(iii) print (“Mean of Age =”, DF[“Age”].mean( ) )
print(“Mode of Age =”, DF[“Age”].mode())
Or
print(“No of rows = ”,DF.count())
Section – E
Question 33.
Consider the table EXAM given below. Write the queries for (i) to (v).
Table : Exam
SNo | Name | Stipend | Subject | Average | Division |
1 | Karan | 400 | English | 68 | 1st |
2 | Aman | 680 | Mathematics | 72 | 1st |
3 | Javed | 500 | Accounts | 67 | Ist |
4 | Bishakh | 200 | Informatics | 55 | IInd |
5 | Sugandha | 400 | History | 35 | IIIrd |
6 | Suparna | 550 | Geography | 45 | IIIrd |
(i) To list the names of those students, who have obtained division as 1st in ascending order of Name.
(ii) To count the number of students, who have either Accounts or Informatics as Subject.
(iii) To display maximum average.
(iv) To display a report listing Name, Subject and annual Stipend received assuming that the Stipend column has monthly stipend.
(v) Identify primary key from given attributes.
Or
Give the output of following commands.
(i) mysql >SELECT TRUNCATE (200.91,1);
(ii) mysql>SELECT LEFT( ‘Swati’ ,4);
(iii) mysql>SELECT CHAR (83, 72, 85, 67, 72, 73);
(iv) mysql>SELECT RTRIM(‘!!!!!Study is important !!!!!’);
Where !!!!! denotes blank spaces
(v) SELECT ROUND (3234.343, 1);
Answer:
(i) SELECT Name FROM EXAM WHERE Division = “Ist” ORDER BY Name;
(ii) SELECT COUNT (*) FROM EXAM WHERE Subject = “Accounts” OR Subject = “Informatics”;
(iii) SELECT MAX (Average) “Highest Average” FROM EXAM;
(iv) SELECT Name, Subject, Stipend * 12 “Stipend” FROM Exam;
(v) SNo
Or
(i) 200.9
(ii) Swat
(iii) SHUCHI
(iv) !!!!! Study is important
(v) 3234.3
Question 34.
Learn Together is an educational NGO. It is setting up its new campus at Jabalpur for its web-based activities. The campus has four compounds as shown in the diagram below:
Centre to centre distance between various compounds as per architectural drawing (in m) is as follows
Main Compound to Resource Compound | 110 m |
Main Compound to Training Compound | 115 m |
Main Compound to Finance Compound | 35 m |
Resource Compound to Training Compound | 25 m |
Resource Compound to Finance Compound | 135 m |
Training Compound to Finance Compound | 100 m |
Expected number of computers in each compound are as follows :
Main Compound | 5 |
Resource Compound | 15 |
Training Compound | 150 |
Finance Compound | 20 |
(i) Suggest a cable layout of connections between the compounds.
(ii) Suggest the most suitable place (i.e. compound) to house the server for this NGO.
Also, provide a suitable reason for your suggestion.
(iii) Suggest the placement of the following devices with justification :
(a) Repeater
(b) Hub/Switch
(iv) The NGO is planning to connect its international office situated in Mumbai, which out of the following wired communication link, will you suggest for a very high speed connectivity?
(a) Telephone analog line
(b) Optical fibre
(c) Ethernet cable
(v) Expand the following:
LAN
PAN
Answer:
(i)
(ii) The most suitable place to house the server is Training Compound as it has maximum number of computers.
(iii) (a) Repeater As per one layout (shown in (i)), the repeater can be avoided as all distances between the compounds are < = 100 m.
(b) Hub/Switch Training compound as it is hosting the server.
(iv) (b) Optical fibre
(v) LAN Local Area Network
PAN Personal Area Network
Question 35.
Write the code for the following graph which display the different style multiline in same plot.
Or
Python provides the facility to draw multiple bar charts in same plot. Shrey used this feature and made multiple bar charts in same plot but by mistake the code of graph has deleted. Now, help him to write the code of given graph.
Answer:
import matplotlib.pyplot as plt x1 = [10, 20, 30] y1 = [20, 40, 10] x2 = [10, 20, 30] y2 = [40, 10, 30] plt.xlabe1(‘x - axis’) plt.ylabe1(‘y - axis’) plt.plot(x1, y1, color=‘black’, linewidth = 5, labe1 = ‘line1-dotted’, linestyle=‘dashed’) plt.plot(x2, y2, color=‘magenta’, linewidth = 3, label = ‘line2-dashed’, linestyle=‘dotted’) plt.title(“Plot with different styles”) plt.legend( ) plt.show( )
Or
import numpy as np import matplotlib.pyplot as pit groups = 5 boys = (45, 23, 62, 16, 33) girls = (55, 18, 31, 46, 29) fig, ax = plt.subplots( ) index = np.arrange(groups) bar_width = 0.35 opacity = 0.8 rects1 = plt.bar(index, boys, bar_width, alpha=opacity, color=‘Red’, label=‘Boys’) rects2 = plt.bar(index + bar_width, girls, bar_width, al pha=opacity, col or=‘ Blue ’, label = ‘Girls’) plt.xlabel(‘Person’) plt.ylabel(‘Scores’) plt.title(‘Multiple Bar Chart’) plt.xticks(index + bar_width, (‘G1’, ‘G2’, ‘G3, ‘G4’, G5’)) plt.legend() plt.tight_layout() plt.show()