SAMPLE QUESTION PAPER (THEORY)
CLASS: XII SESSION: 2024-25
COMPUTER SCIENCE (083)
Time allowed: 3 Hours
Maximum Marks: 70
General Instructions:
● This question paper contains 37 questions.
● All questions are compulsory. However, internal choices have been provided in some questions. Attempt only one of the choices in such questions
● The paper is divided into 5 Sections- A, B, C, D and E.
● Section A consists of 21 questions (1 to 21). Each question carries 1 Mark.
● Section B consists of 7 questions (22 to 28). Each question carries 2 Marks.
● Section C consists of 3 questions (29 to 31). Each question carries 3 Marks.
● Section D consists of 4 questions (32 to 35). Each question carries 4 Marks.
● Section E consists of 2 questions (36 to 37). Each question carries 5 Marks.
● All programming questions are to be answered using Python Language only.
● In case of MCQ, text of the correct answer should also be written.
Section A
1. State True or False:
The Python interpreter handles logical errors during code execution
Ans: False
2. Identify the output of the following code snippet:text = "PYTHONPROGRAM"(a) #THONPROGRAM
text=text.replace('PY','#')
print(text)
(b) ##THON#ROGRAM
(c) #THON#ROGRAM
(d) #YTHON#ROGRAM
3. Which of the following expressions evaluates to False?
(a) not (True) and False
(b) True or False
(c) not (False and True)
(d) True and not (False)
4. What is the output of the expression?country='International'
print(country.split("n"))
(a) ('I', 'ter', 'atio', 'al')
(b) ['I', 'ter', 'atio', 'al']
(c) ['I', 'n', 'ter', 'n', 'atio', 'n', 'al']
(d) Error
5. What will be the output of the following code snippet?message= "World Peace"
print(message[-2::-2])
Ans: ce lo
6. What will be the output of the following code?tuple1 = (1, 2, 3)
tuple2 = tuple1
tuple1 += (4,)
print(tuple1 == tuple2)
(a) True
(b) False
(c) tuple1
(d) Error
7. If my_dict is a dictionary as defined below, then which of the following statements will raise an exception?my_dict = {'apple': 10, 'banana': 20, 'orange': 30}
(a) my_dict.get('orange')
(b) print(my_dict['apple', 'banana'])
(c) my_dict['apple']=20
(d) print(str(my_dict))
8. What does the list.remove(x) method do in Python?
(a) Removes the element at index x from the list
(b) Removes the first occurrence of value x from the list
(c) Removes all occurrences of value x from the list
(d) Removes the last occurrence of value x from the list
9. If a table which has one Primary key and two alternate keys. How many Candidate keys will this table have?
(a) 1
(b) 2
(c) 3
(d) 4
10. Write the missing statement to complete the following code:file = open("example.txt", "r")
data = file.read(100)
________ #Move the file pointer to the
beginning of the file
next_data = file.read(50)
file.close()
Ans: file.seek(0) ( OR file.seek(0,0) )
11. State whether the following statement is True or False:
The finally block in Python is executed only if no exception occurs in the try block.
Ans: False
12. What will be the output of the following code?c = 10
def add():
global c
c = c + 2
print(c,end='#')
add()
c=15
print(c,end='%')
(a) 12%15#
(b) 15#12%
(c) 12#15%
(d) 12%15#
13. Which SQL command can change the degree of an existing relation?
Ans: ALTER
14. What will be the output of the query?SELECT * FROM products WHERE product_name LIKE 'App%';
(a) Details of all products whose names start with ‘App’
(b) Details of all products whose names end with ‘App’
(c) Names of all products whose names start with ‘App’
(d) Names of all products whose names end with ‘App’
15. In which datatype the value stored is padded with spaces to fit the specified length.
(a) DATE
(b) VARCHAR
(c) FLOAT
(d) CHAR
16. Which aggregate function can be used to find the cardinality of a table?
(a) sum()
(b) count()
(c) avg()
(d) max()
17. Which protocol is used to transfer files over the Internet?
(a) HTTP
(b) FTP
(c) PPP
(d) HTTPS
18. Which network device is used to connect two networks that use different protocols?
(a) Modem
(b) Gateway
(c) Switch
(d) Repeater
19. Which switching technique breaks data into smaller packets for transmission, allowing multiple packets to share the same network resources.
Ans: Packet Switching
Q20 and Q21 are Assertion(A) and Reason(R) based questions. Mark the correct choice as:
(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 but R is True
20. Assertion (A): Positional arguments in Python functions must be passed in the exact order in which they are defined in the function signature.
Reasoning (R): This is because Python functions automatically assign default values to positional arguments.
Ans: (c) A is True but R is False
21. Assertion (A): A SELECT command in SQL can have both WHERE and HAVING clauses.
Reasoning (R): WHERE and HAVING clauses are used to check conditions, therefore, these can be used interchangeably
Ans: (c) A is True but R is False
Section-B
22. How is a mutable object different from an immutable object in Python?
Identify one mutable object and one immutable object from the following:(1,2), [1,2], {1:1,2:2}, ‘123’
Ans: A mutable object can be updated whereas an immutable object cannot be
updated.
Mutable object: [1,2]
Immutable object: (1,2)
23. Give two examples of each of the following:
(i) Arithmetic operators
Ans: +, –
(ii) Relational operators
Ans: >, <=
24. If L1=[1,2,3,2,1,2,4,2, . . . ], and L2=[10,20,30, . . .], then (Answer using builtin functions only)
(i) a) Write a statement to count the occurrences of 4 in L1.
Ans: L1.count(4)
OR
b) Write a statement to sort the elements of list L1 in ascending order.
Ans: L1.sort()
(ii) a) Write a statement to insert all the elements of L2 at the end of L1.
Ans: L1.extend(L2)
OR
b) Write a statement to reverse the elements of list L2.
Ans: L2.reverse()
25. Identify the correct output(s) of the following code. Also write the minimum and the maximum possible values of the variable b.
import random
a="Wisdom"
b=random.randint(1,6)
for i in range(0,b,2):
print(a[i],end='#')(a) W#
(b) W#i#
(c) W#s#
(d) W#i#s#
Ans: (a) and (c); Minimum and maximum possible values of the variable b: 1,6
26. The code provided below is intended to swap the first and last elements of a given tuple. However, there are syntax and logical errors in the code.
Rewrite it after removing all errors. Underline all the corrections made.
def swap_first_last(tup)
if len(tup) < 2:
return tup
new_tup = (tup[-1],) + tup[1:-1] + (tup[0])
return new_tup
result = swap_first_last((1, 2, 3, 4))
print("Swapped tuple: " result)def swap_first_last(tup):
if len(tup) < 2:
return tup
new_tup = (tup[-1],) + tup[1:-1] + (tup[0],)
return new_tup
result = swap_first_last((1, 2, 3, 4))
print("Swapped tuple:", result)27. (i) (a) What constraint should be applied on a table column so that duplicate values are not allowed in that column, but NULL is allowed.
Ans: UNIQUE
OR
(b) What constraint should be applied on a table column so that NULL is not allowed in that column, but duplicate values are allowed.
Ans: NOT NULL
(ii) (a) Write an SQL command to remove the Primary Key constraint from a table, named MOBILE. M_ID is the primary key of the table.
Ans: ALTER TABLE MOBILE DROP PRIMARY KEY;
OR
(b) Write an SQL command to make the column M_ID the Primary Key of an already existing table, named MOBILE.
Ans: ALTER TABLE MOBILE ADD PRIMARY KEY (M_ID);
28. (a) List one advantage and one disadvantage of star topology.
Ans: Advantage: Network extension is easy.
Disadvantage: Failure of switch/hub results in failure of the network.
OR
(b) Expand the term SMTP. What is the use of SMTP?
Ans: Simple Mail Transfer Protocol. It is used for sending e-mails from client to server
Section C
29. (a) Write a Python function that displays all the words containing @cmail from a text file “Emails.txt”.
def show():
f=open("Email.txt",'r')
data=f.read()
words=data.split()
for word in words:
if '@cmail' in word:
print(word,end=' ')
f.close()OR
(b) Write a Python function that finds and displays all the words longer than 5 characters from a text file “Words.txt”.
def display_long_words():
with open("Words.txt", 'r') as file:
data=file.read()
words=data.split()
for word in words:
if len(word)>5:
print(word,end=' ')30. A) You have a stack named BooksStack that contains records of books. Each book record is represented as a list containing book_title, author_name, and publication_year.
Write the following user-defined functions in Python to perform the specified operations on the stack BooksStack:
(i) push_book(BooksStack, new_book): This function takes the stack BooksStack and a new book record new_book as arguments and pushes the new book record onto the stack.
def push_book(BooksStack, new_book):
BooksStack.append(new_book)(ii) pop_book(BooksStack): This function pops the topmost book record from the stack and returns it. If the stack is already empty, the function should display “Underflow”.
def pop_book(BooksStack):
if not BooksStack:
print("Underflow")
else:
return(BookStack.pop())(iii) peep(BookStack): This function displays the topmost element of the stack without deleting it. If the stack is empty, the function should display ‘None’.
def peep(BooksStack):
if not BooksStack:
print("None")
else:
print(BookStack[-1])OR
(B) Write the definition of a user-defined function push_even(N) which accepts a list of integers in a parameter N and pushes all those integers which are even from the list N into a Stack named EvenNumbers.
Write function pop_even() to pop the topmost number from the stack and returns it. If the stack is already empty, the function should display “Empty”.
Write function Disp_even() to display all element of the stack without deleting them. If the stack is empty, the function should display ‘None’.
For example:
If the integers input into the list VALUES are:
[10, 5, 8, 3, 12]
Then the stack EvenNumbers should store:
[10, 8, 12]
def push_even(N):
EvenNumbers = []
for num in N:
if num % 2 == 0:
EvenNumbers.append(num)
return EvenNumbers
VALUES = []
for i in range(5):
VALUES.append(int(input("Enter an integer: ")))
EvenNumbers = push_even(VALUES)
def pop_even():
if not EvenNumbers:
print("Underflow")
else:
print(EvenNumbers.pop())
pop_even()
def Disp_even():
if not EvenNumbers:
print("None")
else:
print(EvenNumbers[-1])
Disp_even()31. Predict the output of the following code:
d = {"apple": 15, "banana": 7, "cherry": 9}
str1 = ""
for key in d:
str1 = str1 + str(d[key]) + "@" + “\n”
str2 = str1[:-1]
print(str2)Output: 15@
7@
9
OR
Predict the output of the following code:
line=[4,9,12,6,20]
for I in line:
for j in range(1,I%5):
print(j,’#’,end=””)
print()Output: 1 #2 #3#
1 #2 #3 #
1 #
Section D
32. Consider the table ORDERS as given below.
Note: The table contains many more records than shown here
| O_Id | C_Name | Product | Quantity | Price |
|---|---|---|---|---|
| 1001 | Jitendra | Laptop | 1 | 12000 |
| 1002 | Mustafa | Smartphone | 2 | 10000 |
| 1003 | Dhwani | Headphone | 1 | 1500 |
(a) Write the following queries:
(i) To display the total Quantity for each Product, excluding Products with total Quantity less than 5.
Ans: select Product, sum(Quantity) from orders group by product having sum(Quantity)>=5;
(ii) To display the orders table sorted by total price in descending order.
Ans: select * from orders order by Price desc;
(iii) To display the distinct customer names from the Orders table.
Ans: select distinct C_Name from orders;
(iv) Display the sum of Price of all the orders for which the quantity is null.
Ans: select sum(price) as total_price from orders where Quantity IS NULL;
(b) Write the output:
(i) Select c_name, sum(quantity) as total_quantity from orders group by c_name;
| C_Name | Quantity |
|---|---|
| Jitendra | 1 |
| Mustafa | 2 |
| Dhwani | 1 |
(ii) Select * from orders where product like ‘%phone%’;
| O_Id | C_Name | Product | Quantity | Price |
|---|---|---|---|---|
| 1002 | Mustafa | Smartphone | 2 | 10000 |
| 1003 | Dhwani | Headphone | 1 | 1500 |
(iii) Select o_id, c_name, product, quantity, price from orders where price between 1500 and 12000;
| O_Id | C_Name | Product | Quantity | Price |
|---|---|---|---|---|
| 1001 | Jitendra | Laptop | 1 | 12000 |
| 1002 | Mustafa | Smartphone | 2 | 10000 |
| 1003 | Dhwani | Headphone | 1 | 1500 |
(iv) Select max(price) from orders;
| MAX(Price) |
|---|
| 12000 |
33. A csv file “Happiness.csv” contains the data of a survey. Each record of the file contains the following data:
- Name of a country
- Population of the country
- Sample Size (Number of persons who participated in the survey in that country)
- Happy (Number of persons who accepted that they were Happy)
For example, a sample record of the file may be:[‘Signiland’, 5673000, 5000, 3426]
Write the following Python functions to perform the specified operations on this file:
(i) Read all the data from the file in the form of a list and display all those records for which the population is more than 5000000.
def show():
import csv
f=open("happiness.csv",'r')
records=csv.reader(f)
next(records, None) #To skip the Header row
for i in records:
if int(i[1])>5000000:
print(i)
f.close()(ii) Count the number of records in the file.
def Count_records():
import csv
f=open("happiness.csv",'r')
records=csv.reader(f)
next(records, None) #To skip the Header row
count=0
for i in records:
count+=1
print(count)
f.close()34. Saman has been entrusted with the management of Law University Database. He needs to access some information from FACULTY and COURSES tables for a survey analysis. Help him extract the following information by writing the desired SQL queries as mentioned below.
Table: FACULTY
| F_ID | FName | LName | Hire_Date | Salary |
|---|---|---|---|---|
| 102 | Amit | Mishra | 12-10-1998 | 12000 |
| 103 | Nitin | Vyas | 24-12-1994 | 8000 |
| 104 | Rakshit | Soni | 18-5-2001 | 14000 |
| 105 | Rashmi | Malhotra | 11-9-2004 | 11000 |
| 106 | Sulekha | Srivastava | 5-6-2006 | 10000 |
Table: COURSES
| C_ID | F_ID | CName | Fees |
|---|---|---|---|
| C21 | 102 | Grid Computing | 40000 |
| C22 | 106 | System Design | 16000 |
| C23 | 104 | Computer Security | 8000 |
| C24 | 106 | Human Biology | 15000 |
| C25 | 102 | Computer Network | 20000 |
| C26 | 105 | Visual Basic | 6000 |
(i) To display complete details (from both the tables) of those Faculties whose salary is less than 12000.
Ans: Select * from FACULTY natural join COURSES where Salary<12000;
(ii) To display the details of courses whose fees is in the range of 20000 to 50000 (both values included).
Ans: Select * from courses where fees between 20000 and 50000;
(iii) To increase the fees of all courses by 500 which have “Computer” in their Course names.
Ans: Update courses set fees=fees+500 where CName like ‘%Computer%’;
(iv) (A) To display names (FName and LName) of faculty taking System Design.
Ans: Select FName, LName from faculty natural join courses where Came=”System Design”;
OR
(b) To display the Cartesian Product of these two tables.
Ans: Select * from FACULTY, COURSES;
35. A table, named STATIONERY, in ITEMDB database, has the following structure:
| Field | Type |
|---|---|
| itemNo | int(11) |
| itemName | varchar(15) |
| price | float |
| qty | int(11) |
Write the following Python function to perform the specified operation:AddAndDisplay(): To input details of an item and store it in the table STATIONERY. The function should then retrieve and display all records from the STATIONERY table where the Price is greater than 120.
Assume the following for Python-Database connectivity:
Host: localhost, User: root, Password: Pencil
def AddAndDisplay():
import mysql.connector as mycon
mydb=mycon.connect(host="localhost",user="root", passwd="Pencil",database="ITEMDB")
mycur=mydb.cursor()
no=int(input("Enter Item Number: "))
nm=input("Enter Item Name: ")
pr=float(input("Enter price: "))
qty=int(input("Enter qty: "))
query="INSERT INTO stationery VALUES ({},'{}',{},{})"
query=query.format(no,nm,pr,qty)
mycur.execute(query)
mydb.commit()
mycur.execute("select * from stationery where price>120")
for rec in mycur:
print(rec)SECTION E
36. Surya is a manager working in a recruitment agency. He needs to manage the records of various candidates. For this, he wants the following information of each candidate to be stored:
Experience – float
Candidate_ID – integer
Candidate_Name – string
Designation – string
You, as a programmer of the company, have been assigned to do this job for Surya.
(i) Write a function to input the data of a candidate and append it in a binary file.
import pickle
def input_candidates():
candidates = []
n = int(input("Enter the number of candidates you want to add: "))
for i in range(n):
candidate_id = int(input("Enter Candidate ID: "))
candidate_name = input("Enter Candidate Name: ")
designation = input("Enter Designation: ")
experience = float(input("Enter Experience (in years): "))
candidates.append([candidate_id, candidate_name, designation, experience])
return candidates
candidates_list = input_candidates()
def append_candidate_data(candidates):
with open('candidates.bin', 'ab') as file:
for candidate in candidates:
pickle.dump(candidate, file)
print("Candidate data appended successfully.")
append_candidate_data(candidates_list)(ii) Write a function to update the data of candidates whose experience is more than 10 years and change their designation to “Senior Manager”.
import pickle
def update_senior_manager():
updated_candidates = []
try:
with open('candidates.bin', 'rb') as file:
while True:
try:
candidate = pickle.load(file)
if candidate[3] > 10: # If experience > 10 years
candidate[2] = 'Senior Manager'
updated_candidates.append(candidate)
except EOFError:
break # End of file reached
except FileNotFoundError:
print("No candidate data found. Please add candidates first.")
return
with open('candidates.bin', 'wb') as file:
for candidate in updated_candidates:
pickle.dump(candidate, file)
print("Candidates updated to Senior Manager where applicable.")
update_senior_manager()(iii) Write a function to read the data from the binary file and display the data of all those candidates who are not “Senior Manager”.
import pickle
def display_non_senior_managers():
try:
with open('candidates.bin', 'rb') as file:
while True:
try:
candidate = pickle.load(file)
if candidate[2] != 'Senior Manager': # Check if not Senior Manager
print(f"Candidate ID: {candidate[0]}")
print(f"Candidate Name: {candidate[1]}")
print(f"Designation: {candidate[2]}")
print(f"Experience: {candidate[3]}")
print("--------------------")
except EOFError:
break # End of file reached
except FileNotFoundError:
print("No candidate data found. Please add candidates first.")
display_non_senior_managers()37. Event Horizon Enterprises is an event planning organization. It is planning to set up its India campus in Mumbai with its head office in Delhi. The Mumbai campus will have four blocks/buildings – ADMIN, FOOD, MEDIA, DECORATORS. You, as a network expert, need to suggest the best network-related solutions for them to resolve the issues/problems mentioned in points (I) to (V), keeping in mind the distances between various blocks/buildings and other given parameters.
Block to Block distances (in Mtrs.)
| From | To | Distance |
| ADMIN | FOOD | 42 m |
| ADMIN | MEDIA | 96 m |
| ADMIN | DECORATORS | 48 m |
| FOOD | MEDIA | 58 m |
| FOOD | DECORATORS | 46 m |
| MEDIA | DECORATORS | 42 m |
Distance of Delhi Head Office from Mumbai Campus = 1500 km
Number of computers in each of the blocks/Center is as follows:
| ADMIN | 30 |
| FOOD | 18 |
| MEDIA | 25 |
| DECORATORS | 20 |
| DELHI HEAD OFFICE | 18 |
(i) Suggest the most appropriate location of the server inside the MUMBAI campus. Justify your choice.
Ans: ADMIN Block as it has maximum number of computers.
(ii) Which hardware device will you suggest to connect all the computers within each building?
Ans: Switch
(iii) Draw the cable layout to efficiently connect various buildings within the MUMBAI campus. Which cable would you suggest for the most efficient data transfer over the network?
Ans: -image-
Cable: Coaxial cable
(iv) Is there a requirement of a repeater in the given cable layout? Why/ Why not?
Ans: There is no requirement of the Repeat as the optical fibre cable used for the network can carry the data to much longer distances than within the campus.
(v) A) What would be your recommendation for enabling live visual communication between the Admin Office at the Mumbai campus and the DELHI Head Office from the following options:
a) Video Conferencing
b) Email
c) Telephony
d) Instant Messaging
OR
(b) What type of network (PAN, LAN, MAN, or WAN) will be set up among the computers connected in the MUMBAI campus?
Ans: LAN