CBSE Class 12 Informatics Practices Sample Paper 2026 27 with Solutions PDF Download

Section-A (1 to 21) 21 x 1 = 21 Marks

1. A Pandas Series S1 is created with index labels ['a', 'b', 'c', 'd', 'e']. State whether the following statement is True or False:
"The statement S1['b':'d'] will produce the same result as S1[1:3]." [1 Mark]

Answer: False

Teacher's Note:
a) Slicing with labels includes the end label, so S1['b':'d'] gives the elements at 'b', 'c' and 'd'.
b) Slicing with positions excludes the end position, so S1[1:3] gives only the elements at 'b' and 'c'.

2. Ravi needs to find the total number of characters in the StudentName column. Which SQL function should he use? [1 Mark]
A. COUNT()
B. SIZE()
C. LENGTH()
D. TOTAL()

Answer: C. LENGTH()

Teacher's Note:
a) LENGTH() returns the number of characters in a string.
b) Do not confuse it with COUNT(), which counts rows, not characters.

3. Which type of Intellectual Property Right (IPR) protects an invention by giving the creator exclusive rights to make, use, and sell it for a specific period? [1 Mark]
A. Copyright
B. Trademark
C. Patent
D. Software License

Answer: C. Patent

Teacher's Note:
a) A patent is granted for an invention and gives exclusive rights for a fixed period.
b) Copyright protects creative works and a trademark protects a brand name or logo.

4. While plotting a graph using Matplotlib, which function is used to specify the label for the Y-axis? [1 Mark]
A. label_y()
B. ylabel()
C. yaxis_name()
D. set_y()

Answer: B. ylabel()

Teacher's Note:
a) plt.ylabel() sets the Y-axis label and plt.xlabel() sets the X-axis label.
b) The other options are not Matplotlib functions.

5. I am a networking device that converts digital data from a computer into analog signals for transmission, and then converts incoming analog signals back into digital data for the computer to understand. Who am I? [1 Mark]
A. Repeater
B. Router
C. Modem
D. Switch

Answer: C. Modem

Teacher's Note:
a) Modem stands for MOdulator-DEModulator.
b) Modulation converts digital to analog; demodulation converts analog back to digital.

6. Which of the following is a Data Manipulation Language (DML) command in SQL? [1 Mark]
A. ALTER
B. DROP
C. UPDATE
D. CREATE

Answer: C. UPDATE

Teacher's Note:
a) UPDATE changes the data stored in a table, so it is a DML command.
b) ALTER, DROP and CREATE change the structure of the table, so they are DDL commands.

7. The process of re-selling old electronic goods after minor repairs or modification is called: [1 Mark]
A. Recycling
B. Refurbishing
C. Reducing
D. Leaching

Answer: B. Refurbishing

Teacher's Note:
a) Refurbishing means repairing old goods so that they can be sold and used again.
b) Keywords to match: "minor repairs" and "re-selling".

8. What will be the output of the following code?
import pandas as pd
print(pd.Series(5, index=[0, 1, 2])) [1 Mark]
A. A Series with values 5, 5, 5
B. A Series with value 5 only at index 0
C. A Series with values 0, 1, 2
D. Error

Answer: A. A Series with values 5, 5, 5

Teacher's Note:
a) When a scalar value is given with an index, the value is repeated for every index label.
b) Here the index has 3 labels (0, 1, 2), so 5 appears three times.

9. Fill in the blank:
The SQL clause used to filter the groups formed by the GROUP BY clause based on a specific condition is ____________. [1 Mark]

Answer: HAVING

Teacher's Note:
a) HAVING puts a condition on groups, while WHERE puts a condition on individual rows.
b) HAVING is written after GROUP BY.

10. Riya visited an online shopping website, and it saved small text files on her computer to remember her preferences and session details. What are these files called? [1 Mark]
A. Plug-ins
B. Add-ons
C. Cookies
D. Scripts

Answer: C. Cookies

Teacher's Note:
a) Cookies are small text files that a website stores on the user's computer.
b) They help the website remember preferences and session details.

11. Which keyword is used with the ORDER BY clause to sort data in descending order? [1 Mark]
A. DESC
B. DOWN
C. DSC
D. REVERSE

Answer: A. DESC

Teacher's Note:
a) DESC sorts in descending order and ASC sorts in ascending order.
b) If no keyword is given, ORDER BY sorts in ascending order by default.

12. If we add two Pandas Series that do not have matching index labels, the result for those non-matching indices will be: [1 Mark]
A. 0
B. Error
C. NaN
D. Empty string

Answer: C. NaN

Teacher's Note:
a) Pandas adds values by matching index labels.
b) If a label is present in only one Series, the result for that label is NaN (Not a Number).

13. The process of buying electronic gadgets only when necessary to minimize the generation of electronic waste is an example of which 'R' of e-waste management? [1 Mark]
A. Recycle
B. Reuse
C. Reduce
D. Refurbish

Answer: C. Reduce

Teacher's Note:
a) Reduce means cutting down the generation of e-waste by buying only what is needed.
b) Keyword to match: "only when necessary".

14. Which SQL function is used to extract a specific number of characters from a string starting from a given position? [1 Mark]
A. LEFT()
B. RIGHT()
C. LENGTH()
D. MID()

Answer: D. MID()

Teacher's Note:
a) MID(string, position, n) returns n characters starting from the given position.
b) LEFT() and RIGHT() always start from the ends of the string.

15. Aman is exporting a Pandas DataFrame to a CSV file using the to_csv() function. He wants to save only the data and avoid writing the row indices to the file. Which parameter should he set to False to prevent the indices from being included? [1 Mark]
A. header
B. sep
C. index
D. columns

Answer: C. index

Teacher's Note:
a) Writing df.to_csv('file.csv', index=False) saves the data without the row indices.
b) header=False would drop the column names, not the row indices.

16. Fill in the blank:
The process of storing a website on a web server so that it can be accessed over the internet is known as ________. [1 Mark]

Answer: Web hosting (or Hosting)

Teacher's Note:
a) Web hosting makes the website files available on a server connected to the internet.
b) Either "Web hosting" or "Hosting" is accepted.

17. A HR manager queries an employee database. He wants to retrieve only those records where the Commission field actually contains a value. Which SQL condition should he use? [1 Mark]
A. WHERE Commission != NULL
B. WHERE Commission IS NOT NULL
C. WHERE Commission <> NULL
D. WHERE Commission NOT NULL

Answer: B. WHERE Commission IS NOT NULL

Teacher's Note:
a) NULL values are checked only with IS NULL or IS NOT NULL.
b) Comparison operators like != cannot be used with NULL.

18. When creating a DataFrame from a list of dictionaries, the dictionary keys become: [1 Mark]
A. Row indices
B. Data values
C. Column labels
D. Positional Index

Answer: C. Column labels

Teacher's Note:
a) Each dictionary becomes one row, and its keys become the column labels.
b) A key missing in a dictionary gives NaN in that row.

19. State whether the following statement is True or False:
In SQL, the BETWEEN operator is inclusive of both the lower and upper values specified in the range. [1 Mark]

Answer: True

Teacher's Note:
a) BETWEEN 10 AND 20 includes both 10 and 20.
b) It is the same as writing value >= 10 AND value <= 20.

Q. 20 and Q. 21 are Assertion (A) and Reason (R) type questions. Choose the correct option as:

20. Assertion (A) The statement df.drop('Science', axis=0) will remove the column labeled 'Science' from the DataFrame.
Reason (R) In Pandas drop() method, axis=0 refers to row-wise operations and axis=1 refers to column-wise operations. [1 Mark]
A. Both Assertion (A) and Reason (R) are True and Reason (R) is the correct explanation for Assertion (A).
B. Both Assertion (A) and Reason (R) are True and Reason (R) is not the correct explanation for Assertion (A).
C. Assertion (A) is True and Reason (R) is False.
D. Assertion (A) is False, but Reason (R) is True.

Answer: D. Assertion (A) is False, but Reason (R) is True.

Teacher's Note:
a) With axis=0, drop() looks for a row label 'Science', so it does not remove the column.
b) To remove the column, write df.drop('Science', axis=1).

21. Assertion (A) In SQL, the query select * from emp; and SELECT * FROM EMP; will produce the same result.
Reason (R) SQL is a case-sensitive language. [1 Mark]
A. Both Assertion (A) and Reason (R) are True and Reason (R) is the correct explanation for Assertion (A).
B. Both Assertion (A) and Reason (R) are True and Reason (R) is not the correct explanation for Assertion (A).
C. Assertion (A) is True and Reason (R) is False.
D. Assertion (A) is False, but Reason (R) is True.

Answer: C. Assertion (A) is True and Reason (R) is False.

Teacher's Note:
a) SQL keywords are not case-sensitive, so both queries give the same result.
b) Since SQL is not case-sensitive, the Reason is False.

Section-B (22 to 28) 7X2 = 14 Marks

22. (A) (i) Explain the use of the head() function in a Pandas DataFrame.
(ii) What happens if the parameter n is not specified in the head() function? [2 Marks]

Answer:
(i) The head() function displays the first n rows of a DataFrame.
(ii) If n is not specified in head(), it returns the first 5 rows by default.

Teacher's Note:
a) Write "first n rows" for (i) and "5 rows by default" for (ii); each part carries 1 mark.
b) tail() works the same way but shows the last n rows.

OR

(B) Explain the concept of Boolean Indexing in DataFrames. Write a small Python code example to demonstrate it. [2 Marks]

Answer:
Boolean indexing is a technique used to select subsets of data based on the actual values in the DataFrame rather than on row/column labels.
Example:
import pandas as pd
data = [
    {'Name': 'Aarav', 'Age': 24},
    {'Name': 'Priya', 'Age': 30}
]
df = pd.DataFrame(data)
print(df['Age'] > 25)
Output:
0 False
1 True

Teacher's Note:
a) The condition df['Age'] > 25 gives True or False for every row; 1 mark is for the concept and 1 mark for the example.
b) Pandas also prints "Name: Age, dtype: bool" below the output.
c) Writing df[df['Age'] > 25] would display only the rows where the condition is True.

23. Differentiate between an Active and a Passive digital footprint. [2 Marks]

Answer:
1. Active digital footprint: It is created when a person intentionally shares or submits information online.
2. Passive digital footprint: It is created when information is collected automatically, often without the user's knowledge or direct involvement.

Teacher's Note:
a) The key difference is "intentionally" (active) versus "automatically / without knowledge" (passive).
b) Define both terms; defining only one does not show the difference.

24. Define Data Visualization and state its primary purpose. [2 Marks]

Answer:
1. Definition: Data visualization is the graphical or pictorial representation of data using graphs, charts, etc.
2. Purpose: Its primary purpose is to visualize variations or show relationships between variables. This helps users to infer conclusions that might not be easily visible by looking at raw numerical data.

Teacher's Note:
a) 1 mark is for the definition and 1 mark for the purpose.
b) Keywords: "graphical representation", "relationships between variables", "infer conclusions".

25. (A) Define Star Topology. Mention one major advantage of using it. [2 Marks]

Answer:
1. Definition: In star topology, each node is directly connected to a central controller (hub or switch).
2. Advantage: Failure of one node does not affect the rest of the network.

Teacher's Note:
a) Keywords: "each node" and "central hub or switch".
b) Give only one advantage, as asked.

OR

(B) What is VoIP? State any one advantages of using VoIP for communication. [2 Marks]

Answer:
1. VoIP stands for Voice over Internet Protocol. It allows voice transmission over a computer network rather than traditional telephone lines.
2. Advantage: It is very economical, or even free, compared to traditional international calls.

Teacher's Note:
a) Write the full form of VoIP correctly.
b) 1 mark is for the meaning and 1 mark for the advantage.

26. Write SQL queries for the following requirements:
(i) Display the last 3 characters of the attribute Ename from the EMPLOYEE table.
(ii) Find the position of the substring 'ma' in the string 'Informatics'. [2 Marks]

Answer:
(i) SELECT RIGHT(Ename, 3) FROM EMPLOYEE;
(ii) SELECT INSTR('Informatics', 'ma');

Teacher's Note:
a) RIGHT(str, n) returns the last n characters of a string.
b) INSTR(str, substr) returns the position of the first occurrence of substr; here it returns 6.

27. Mention and briefly explain any two guidelines of netiquette. [2 Marks]

Answer:
1. Be Ethical: Do not violate copyright laws. Always seek permission before using or sharing copyrighted material.
2. Be Respectful: Respect the privacy, opinions and cultural diversity of others, especially in public online forums.

Teacher's Note:
a) Name the guideline and then explain it in one line; 1 mark for each guideline.
b) Give exactly two guidelines, as the question asks.

28. (A) Consider the following two dictionaries:
dict1 = {'a': 10, 'b': 20}
dict2 = {'a': 5, 'b': 10, 'c': 20}
Write Python code to create a DataFrame from a list containing the above two dictionaries. [2 Marks]

Answer:
import pandas as pd
dict1 = {'a': 10, 'b': 20}
dict2 = {'a': 5, 'b': 10, 'c': 20}
df = pd.DataFrame([dict1, dict2])
print(df)

Teacher's Note:
a) Pass the two dictionaries inside a list: pd.DataFrame([dict1, dict2]).
b) Key 'c' is missing in dict1, so row 0 gets NaN in column c.

OR

(B) Mention the purpose of read_csv() and explain the use of its sep parameter. [2 Marks]

Answer:
1. read_csv() is used to load data from a CSV file into a Pandas DataFrame.
2. sep: It specifies the delimiter (separator) used in the file, for example a comma or a semicolon.

Teacher's Note:
a) 1 mark is for the purpose and 1 mark for the sep parameter.
b) Example: pd.read_csv('data.csv', sep=';') reads a file whose values are separated by semicolons.

Section-C (29 to 32) 4X3 = 12 Marks

29. Consider the following digital security scenarios and answer the questions:
(i) Mehak receives an SMS from an unknown number stating she has won a lottery. To claim it, she must click a link and enter her Aadhaar number and bank OTP. What type of cybercrime is this?
(ii) A group of people repeatedly post insulting comments and spread rumors about a classmate on a social media platform to distress them. What is this activity called?
(iii) Suggest one Communication Etiquette that should be followed to maintain credibility while participating in an online discussion forum. [3 Marks]

Answer:
(i) Phishing
(ii) Cyber Bullying
(iii) Be Credible / Use polite language.

Teacher's Note:
a) Phishing tricks people into giving personal details like Aadhaar number or OTP through fake messages or links.
b) Repeated insulting posts and rumors meant to distress someone are cyber bullying.
c) Each part carries 1 mark.

30. (A) (i) Write a Python program to create a Pandas Series named Inventory from the following dictionary:
stock = {'Pens': 150, 'Erasers': 80, 'Sharpeners': 60, 'Notebooks': 200}.
(ii) Consider two Series S1 and S2:
import pandas as pd
S1 = pd.Series([10, 20], index=['a', 'b'])
S2 = pd.Series([30, 40], index=['b', 'c'])
Write the output of the statement: print(S1 + S2) [3 Marks]

Answer:
(i)
import pandas as pd
stock = {'Pens': 150, 'Erasers': 80, 'Sharpeners': 60, 'Notebooks': 200}
Inventory = pd.Series(stock)
print(Inventory)
(ii) Output:
a NaN
b 50.0
c NaN

Teacher's Note:
a) When a Series is made from a dictionary, the keys become the index and the values become the data; the program carries 2 marks.
b) Only label 'b' is common, so b = 20 + 30 = 50; labels 'a' and 'c' give NaN.
c) NaN makes the result float, so 50 is shown as 50.0 (Pandas also prints dtype: float64).

OR

(B) Consider a DataFrame df as shown below:
  | Name | IP | Maths
0 | Arpit | 95 | 88
1 | Vani | 89 | 92
2 | Chetan | 78 | 80
Write Pandas statements to perform the following actions:
(i) Add a new column 'Total' containing the values [183, 181, 158].
(ii) Rename the 'Name' column to 'Student'.
(iii) Delete the 'Maths' column from the DataFrame. [3 Marks]

Answer:
(i) df['Total'] = [183, 181, 158]
(ii) df.rename(columns={'Name': 'Student'}, inplace=True)
(iii) df.drop(columns=['Maths'], inplace=True)

Teacher's Note:
a) Without inplace=True, rename() and drop() return a new DataFrame and df stays unchanged.
b) df.drop('Maths', axis=1, inplace=True) is another correct way to delete the column.
c) Each part carries 1 mark.

31. Consider the table HOSPITAL, which contains the following columns:
Column Name | Remark
PNo | Patient Number
PName | Patient Name
Dept | Department
DOA | Date of Admission
Table: HOSPITAL
PNo | PName | Dept | DOA
101 | Ravi Kumar | Cardiology | 2024-05-12
102 | Anita Sharma | Neurology | 2025-06-01
103 | Mohan Das | Cardiology | 2023-05-18
104 | Seema Verma | Orthopedics | 2022-04-22
105 | Rahul Singh | Cardiology | 2025-03-30
Write SQL queries to perform the following tasks:
(i) Display the names of all patients in the Cardiology department in lowercase.
(ii) Display each patient's number along with the day name of the week on which they were admitted.
(iii) Display the patient names arranged in alphabetical order. [3 Marks]

Answer:
(i) SELECT LOWER(PName) FROM HOSPITAL WHERE Dept = 'Cardiology';
(ii) SELECT PNo, DAYNAME(DOA) FROM HOSPITAL;
(iii) SELECT PName FROM HOSPITAL ORDER BY PName ASC;

Teacher's Note:
a) LOWER() (or LCASE()) converts text to lowercase; DAYNAME() gives the weekday name such as Sunday.
b) ORDER BY sorts in ascending order by default, so ASC is optional.
c) Put text values like 'Cardiology' in quotes.

32. (A) Consider a table named STUDENT containing the following data:
ID | Name | DOB
1 | Aman | 2005-08-15
2 | Vinod | 2006-01-26
3 | Saurabh | 2004-01-01
Write the output of the following SQL queries:
(i) SELECT UPPER(Name), LENGTH(Name) FROM STUDENT WHERE ID = 2;
(ii) SELECT DAY(DOB), YEAR(DOB) FROM STUDENT WHERE ID = 3;
(iii) SELECT RIGHT(Name, 3) FROM STUDENT WHERE ID = 1; [3 Marks]

Answer:
(i)
UPPER(Name) | LENGTH(Name)
VINOD | 5
(ii)
DAY(DOB) | YEAR(DOB)
1 | 2004
(iii)
RIGHT(Name, 3)
man

Teacher's Note:
a) For ID 2, Name is 'Vinod', which has 5 characters.
b) For ID 3, DOB is 2004-01-01, so DAY gives 1 and YEAR gives 2004.
c) The last 3 characters of 'Aman' are 'man'.

OR

(B) Write the output of the following SQL queries:
(i) SELECT POWER(MOD(13, 5), 2);
(ii) SELECT UCASE(MID("Digital India", 9, 5));
(iii) SELECT LENGTH(TRIM(" Informatics ")); [3 Marks]

Answer:
(i) 9
(ii) INDIA
(iii) 11

Teacher's Note:
a) MOD(13, 5) = 3 and POWER(3, 2) = 9.
b) MID("Digital India", 9, 5) gives "India" (position 8 is the space), and UCASE makes it "INDIA".
c) TRIM() removes the spaces at both ends, leaving "Informatics" with 11 characters.

Section-D (33 to 34) 2X4 = 8 Marks

33. Write a Python program using Matplotlib to plot a Line Graph showing the "Monthly Sales" of a shop with the following data:
Months: ['Jan', 'Feb', 'Mar', 'Apr']
Sales: [12000, 15000, 11000, 18000]
The program should include:
- Code to import the required library.
- Code to plot the line graph with a label "Sales".
- A title "Sales Performance".
- Labels for both X-axis ("Month") and Y-axis ("Amount").
- Code to display the legend and show the plot. [4 Marks]

Answer:
import matplotlib.pyplot as plt
months = ['Jan', 'Feb', 'Mar', 'Apr']
sales = [12000, 15000, 11000, 18000]
plt.plot(months, sales, label="Sales")
plt.title("Sales Performance")
plt.xlabel("Month")
plt.ylabel("Amount")
plt.legend()
plt.show()

Teacher's Note:
a) Marks: 1 for the import, 1 for plot() with label, and half a mark each for title, labels, legend and show.
b) plt.legend() shows the legend only if a label is given in plot().
c) Call plt.show() last, after all the settings.

34. (A) Consider the following tables:
Table: SPORTS
RegNo | SName | Game | Fees
101 | Aryan | Cricket | 500
102 | Riya | Tennis | 600
103 | Kabir | Cricket | 500
104 | Ishaan | Tennis | 600
105 | Tejas | Football | 750
Table: COACH
CoachID | CName | Game
C1 | Venkatesh | Cricket
C2 | Rameshwar | Tennis
C3 | Sridhar | Football
Write SQL queries for the following:
(i) Display the Game name and the total fees collected for each game, but only for those games where the total fees exceed 1000.
(ii) Display the Student Name (SName) and their respective Coach Name (CName). [4 Marks]

Answer:
(i) SELECT Game, SUM(Fees) FROM SPORTS GROUP BY Game HAVING SUM(Fees) > 1000;
(ii) SELECT SName, CName FROM SPORTS, COACH WHERE SPORTS.Game = COACH.Game;

Teacher's Note:
a) A condition on SUM() must go in HAVING, not in WHERE; here only Tennis (1200) qualifies.
b) The join condition SPORTS.Game = COACH.Game links each student to the coach of the same game.
c) Each part carries 2 marks.

OR

(B) Consider the following tables:
Table: Employee
EmpID | Name | DeptID | Salary
301 | Aarav | D1 | 5200
302 | Riya | D2 | 7500
303 | Kabir | D2 | 6800
304 | Ananya | D3 | 4000
305 | Ishaan | D1 | 4900
Table: Department
DeptID | DeptName
D1 | HR
D2 | IT
D3 | Sales
Write the output of the following SQL queries:
(i) SELECT DeptID, COUNT(*), MAX(Salary) FROM Employee GROUP BY DeptID HAVING COUNT(*) > 1 ORDER BY DeptID;
(ii) SELECT Name, DeptName FROM Employee, Department WHERE Employee.DeptID = Department.DeptID AND Employee.Salary > 6000; [4 Marks]

Answer:
(i)
DeptID | COUNT(*) | MAX(Salary)
D1 | 2 | 5200
D2 | 2 | 7500
(ii)
Name | DeptName
Riya | IT
Kabir | IT

Teacher's Note:
a) D3 has only one employee, so HAVING COUNT(*) > 1 leaves it out.
b) Only Riya (7500) and Kabir (6800) earn more than 6000, and both are in D2 (IT).
c) Write the column headings along with the rows in output questions.

Section-E (35 to 37) 3X5 = 15 Marks

35. Tech-Innovate Pvt Ltd is a leading technology solutions provider renowned for delivering innovative digital services to clients worldwide. The company operates from a spacious campus comprising four blocks: Block A, Block B, Block C, and Block D.
To ensure smooth communication, centralized data storage, and high-speed connectivity across the campus, the organization plans to set up a structured network connecting all blocks.
The following tables provide the distances between the blocks and the number of computers in each block.
From | To | Distance (meters)
Block A | Block B | 40 m
Block A | Block C | 50 m
Block A | Block D | 160 m
Block B | Block C | 70 m
Block B | Block D | 60 m
Block C | Block D | 120 m
Block | Number of Computers
Block A | 25
Block B | 60
Block C | 15
Block D | 150
As a network engineer, answer the following questions based on the details given above: [5 Marks]

[Figure: Campus layout titled "Tech-Innovate Pvt Ltd" showing four blocks - Block A and Block B in the top row, Block C and Block D in the bottom row.]

(i) Suggest the most suitable block to install the server. Justify your answer. [1 Mark]

Answer: Block D. It is the most suitable block because it has the maximum number of computers (150).

Teacher's Note:
a) The server is placed in the block with the most computers, so that most of the traffic stays within that block.
b) Always give the justification; the block name alone is not enough.

(ii) What type of network (PAN, LAN, MAN, or WAN) will be formed within the campus? [1 Mark]

Answer: LAN (Local Area Network), because the network lies within a single campus (a limited area).

Teacher's Note:
a) A network spread over one building or campus is a LAN.
b) MAN covers a city and WAN covers countries.

(iii) Suggest the placement of a Switch with suitable justification. [1 Mark]

Answer: Every block (A, B, C and D) should have a switch, to connect the multiple computers within that block.

Teacher's Note:
a) A switch connects many computers of the same block to form a network.
b) Mention both the placement (every block) and the reason.

(iv) The company wants to host a website where clients can log in and see real-time project updates. Should they develop a Static or a Dynamic website? Why? [1 Mark]

Answer: Dynamic website. Since it involves user logins and real-time data updates from a database, a dynamic website is required.

Teacher's Note:
a) A static website shows the same fixed content to every visitor.
b) Keywords for the reason: "user login" and "real-time updates".

(v) Identify between which blocks a repeater is needed and justify your answer. [1 Mark]

Answer: A repeater is needed between Block A and Block D, and between Block C and Block D, because the distance exceeds about 100 m for Ethernet.

Teacher's Note:
a) A-D is 160 m and C-D is 120 m, both more than 100 m.
b) A repeater regenerates the weak signal over long cable lengths.

36. (i) Create a DataFrame named StoreDF as shown below using dictionary of series:
  | Items | Quantity | Unit_Price
0 | Bread | 50 | 30
1 | Milk | 100 | 25
2 | Eggs | 120 | 6 [3 Marks]

Answer:
import pandas as pd
data = {
    'Items': pd.Series(['Bread', 'Milk', 'Eggs']),
    'Quantity': pd.Series([50, 100, 120]),
    'Unit_Price': pd.Series([30, 25, 6])
}
StoreDF = pd.DataFrame(data)
print(StoreDF)

Teacher's Note:
a) Each column is made from a separate pd.Series, and the dictionary keys become the column names.
b) The default index 0, 1, 2 is created automatically.

Write suitable Pandas statements to Perform the following operations:
(ii) Add a new row containing data [Butter, 40, 55] [1 Mark]

Answer: StoreDF.loc[3] = ['Butter', 40, 55]

Teacher's Note:
a) loc with a new index label (3) adds a new row at the end.
b) Put the text value 'Butter' in quotes.

(iii) Display values of Items column only, [1 Mark]

Answer: print(StoreDF['Items'])

Teacher's Note:
a) A single column is selected by writing its name in square brackets.
b) StoreDF.Items also selects the same column.

37. (A) Refer to the table given below:
Table: BOOK
BookID | Title | Author | Price
201 | Wings of Fire | A P J Abdul Kalam | 350
202 | The Guide | R. K. Narayan | 299
203 | The God of Small Things | Arundhati Roy | 399
204 | Malgudi Days | R. K. Narayan | 280
Write SQL commands for the following tasks:
(i) Insert a new record into the table with the values: 205, The White Tiger, Aravind Adiga, 350.
(ii) Update the Price of the book with BookID 202 to 325.
(iii) Delete the records of all books written by 'R. K. Narayan'.
(iv) Add a new column Publisher of type VARCHAR(30) to the table.
(v) Drop the table BOOK from the database. [5 Marks]

Answer:
(i) INSERT INTO BOOK VALUES (205, 'The White Tiger', 'Aravind Adiga', 350);
(ii) UPDATE BOOK SET Price = 325 WHERE BookID = 202;
(iii) DELETE FROM BOOK WHERE Author = 'R. K. Narayan';
(iv) ALTER TABLE BOOK ADD Publisher VARCHAR(30);
(v) DROP TABLE BOOK;

Teacher's Note:
a) Never forget the WHERE clause in UPDATE and DELETE, or every row will be changed or deleted.
b) ALTER TABLE changes the structure; DROP TABLE removes the whole table with its data.
c) Each part carries 1 mark.

OR

(B) Consider a table named PRODUCT, which contains the following columns: PCode, PName, Category, Qty, Price, ExpiryDate.
The columns are described as follows:
PCode - A unique code assigned to each product.
PName - The name of the product.
Category - The category or type of the product.
Qty - The available quantity of the product.
Price - The unit price of the product.
ExpiryDate - The expiration date of the product.
Write SQL queries for:
(i) Display PName and its Price rounded to one decimal place.
(ii) Display the names of products that end with the letter 's'.
(iii) Display the PName and Category of those products whose Price is less than or equal to 500.
(iv) Display the total quantity of all products.
(v) Display PName after removing leading spaces only. [5 Marks]

Answer:
(i) SELECT PName, ROUND(Price, 1) FROM PRODUCT;
(ii) SELECT PName FROM PRODUCT WHERE RIGHT(PName, 1) = 's';
(iii) SELECT PName, Category FROM PRODUCT WHERE Price <= 500;
(iv) SELECT SUM(Qty) FROM PRODUCT;
(v) SELECT LTRIM(PName) FROM PRODUCT;

Teacher's Note:
a) ROUND(Price, 1) keeps one digit after the decimal point.
b) For (ii), WHERE PName LIKE '%s' is another correct way.
c) LTRIM() removes only leading spaces, RTRIM() removes trailing spaces and TRIM() removes both.