Computer Science (083)

CLASS XII
Time: 3 Hours Max. Marks: 70
General Instructions:
1. This question paper contains 37 questions.
2. All questions are compulsory. However, internal choices have been provided in some questions. Attempt
only one of the choices in such questions
3. The paper is divided into 5 Sections- A, B, C, D and E.
4. Section A consists of 21 questions (1 to 21). Each question carries 1 Mark.
5. Section B consists of 7 questions (22 to 28). Each question carries 2 Marks.
6. Section C consists of 3 questions (29 to 31). Each question carries 3 Marks.
7. Section D consists of 4 questions (32 to 35). Each question carries 4 Marks.
8. Section E consists of 2 questions (36 to 37). Each question carries 5 Marks.
9. All programming questions are to be answered using Python Language only.
10. In case of MCQ, text of the correct answer should also be written.

SECTION A

1. State True or False

“A tuple is a immutable data type.”

2. The alternate to math.pow() function is______operator.

(a) ** (b) c $
(c) + = (d) /

3. Two tables are joined using a common field known as ______.

(a) Alternate key (b) Foreign key
(c) Candidate key (d) None of these

4. To print all elements of tuple in reverse order using______.

(a) [: – 1] (b) [: : – 1]
(c) [1 : : ] (d) [: : 1]

5. Given : s=“Rajkumar@gmail.com”. What will be the output of print(s[2: :2])?

(a) ‘juagalcm’ (b) ‘jua@galcm’
(c) ‘ajua@galcm’’ (d) ‘jua@gmalcm’’
6. What will be the output of the following code snippet?
sentence = “Learning Python”
print(sentence[8:15])

7. Which of the following Python functions do not require importing of a module?

(a) type() (b) input()
(c) sqrt() (d) Both (a) and (b)

8. Which of the following modes open a text file, such that the new data is written in it keeping the existing
contents ?
(a) r+ (b) rw+
(c) w+ (d) a

9. The_____clause with the update command specifies the attribute to be modified.

(a) FIELD (b) ATTRIBUTE
(c) CHANGE (d) SET

10. Complete the code by filling in the blank with the appropriate line to move the file pointer:
file = open(“output.txt”, “r”)
data = file.read(20)
file.seek(5) # Move the file pointer to position 5
next_data = file.read(10)
file.close()

11. State whether the following statement is True or False:

The `raise` statement in Python is used to manually trigger an exception.

12. Which type of network is typically used for a single site, covering a small range around an individual, such
as in a home or office setup?
(a) DSL (b) RAM
(c) WAN (d) PAN

13. Determine the output of the following code:

s1 = ‘Hello’
s2 = ‘World’
s = s1 + s2
print(s)
(a) Hello World (b) HelloWorld
(c) ‘Hellow’ ‘World’ (d) Error

14. The_____clause with GROUP BY, can filter groups from the query output.
(a) WHERE (b) FILTER
(c) HAVING (d) CHECK
15. Given a list L= [6,12,9,40,2,1]. Which of the following statements will arrange the list in reverse order
(a) L.arrange() (b) L.sort()
(c) L.sort(reverse=True) (d) L.sort(reverse=False)

16. Which method returns the next row from the result set as a tuple?
(a) fetchone( ) (b) fetchmany( )
(c) fetchall( ) (d) rowcount

17. An alternate key can be

(a) only 1 in a table. (b) a table can have maximum 2 alternate keys.
(c) a table can have at most 3 alternate keys. (d) multiple in a relation.

18. Which SQL category provides statements for manipulating database objects?
(a) DDL (b) DML
(c) DCL (d) TCL

19. Which attribute is used to return access mode with that file was opened?
(a) file.mode (b) mode.file
(c) file*mode (d) None of these

Directions : (Q. Nos. 20 and 21) are Assertion and Reason based questions.

20. Assertion (A) : A python function can return more than one value to the calling function.
Reason (R) : The return statement takes only a list as parameter.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

21. Assertion (A) : While opening a binary file the mode may not be specified.
Reason (R) : The open function for file opening by default takes the mode parameter as ‘rb’ for binary files,
if no mode is specified.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
 SECTION B
22. Find the output of the following code :
i = 1
while(i < 5):
print(i)
i = i * 2

23. (a) Correct the error if any in the following statement.

(i) a + 5 = b
(ii) 1 = 2b + c * d
(iii) name = Aryan
(iv) a = 20
print a;
(b) Evaluate the following expression
If a = b = 10, c = 5
a = b*3//4 + c//4 + 4– b + 5//6

24. Provide one appropriate example of a URL and a domain name.

o
Is it possible to use a URL to access a webpage? If so, how?

25. Explain the UPDATE command in SQL, including its basic syntax and an example.

26. (a) Write any two characteristics of IP address.

(b) What is VoIP?

27. Write the one example of following terms.

(i) Identifier (ii) Punctuator
(iii) Keyword (iv) Constant


o
What will be the output of the following code?
a, b = 8, 4
x, y = a + b, b - 2
z = x - y
print(“x:”, x, “y:”, y, “z:”, z)

28. Expand the following abbreviation :

(i) SQL (ii) DML
(iii) DDL (iv) TCL


o
Mention two characteristics of SQL.
 SECTION C
29. Write a Python function that accepts a sentence and counts the occurrences of the words “is” and “was”.
Example
Input: “It is what it is. The situation was complex and still is.”
Output:
Number of “is”: 3
Number of “was”: 1


o
Write a definition of a function that takes input a sentence and display the list of words that start with a
lowercase vowel and list of words that start with a uppercase vowel separately.
Example
Input : A quick black elephant enters Into a jungle.
Output
List of words starting with lowercase vowels [‘elephant’, ‘enters’, ‘a’]
List of words starting with uppercase vowels [‘A’, ‘Into’]

30. How can you create a Python function to repeatedly accept person names and add them to a list, ensuring
that each name only contains letters, spaces, and periods (.) without any digits?


o
Find the final contents of a stack that encounters the following tokens.
Assume that an operand is pushed to stack and a binary operator pops two operands from stack and pushes
the result to the stack.
100,8,3,*,50,2,+,+,*

31. Write a program that calculates the sum and mean of a series of numbers entered by the user.


o
A user-defined method to open a text file “para.txt” and write its contents to another file fter removing the
3rd line
def Func():
with open (‘Para.txt’, ‘r’) as f:
l=f.readlines()
f.close()
print(l)
del l[3]
print(l)
f=open (‘Para.txt’, ‘w’)
f...........
f.close()
(a) Which module needs to be imported to use operating system functions like rename() and remove().
(b) Write the function name to open a text file.
(c) Fill the blank as marked in above code.
 SECTION D
32. (a) Write a Python program to find maximum and minimum elements in a tuple.
(b) Consider the table MobileStock with following fields
M_Id, M_Name, M_Qty, M_Supplier
Write the Python code to fetch all records with fields M_Id, M_Name and M_Supplier from database
Mobile.


o
(a) Which of the following are invalid names and why?
(i) Paidlnterest (ii) S-num
(iii) Percent (iv) 123
(b) Write the steps for Database connectivity with short explanation of each step.

33. What does tell() method do?

(a) AddRegistration() :To accept more student registration data and store them to the binary file keeping
the existing registration data.
A Binary file “Registration.dat” exists storing details of students who have been registeredfor CBSE
board exams. The file stores following data of students :
RegnNo StudName class No of subjects
(b) CountRegistrations() : Display count of registrations using the functions.

34. Consider the following tables PRODUCT and CLIENT

TABLE : PRODUCT
PID ProductName Manufacturer Price
TP01 Powder LAK 40
FW05 Face Cleaner ABC 45
BS01 Liquid Soap ABC 55
SH06 Dove Shampoo XYZ 120
FW12 Face Wash XYZ 95

TABLE : CLIENT
C_ID ClientName City P_ID
01 Cosmetic Shop Delhi FW05
06 Total Health Mumbai BS01
12 Life care Delhi SH06
15 Pretty Store Delhi FW12
16 Dreams Bengaluru TP01
(a) To display the ClientName, City from table CLIENT and ProductName and Price from table PRODUCT,
with their corresponding matching P_ID.
(b) Write SQL queries for statements (i) to (iv)
 (i) To display the details of those Clients, whose City is Delhi.
(ii) To display the details of products, whose Price is in the range of 50 to 100 (both values included).
(iii) To display product name and their manufacturer whose Price is more than 100.
(iv) To display client name for those whose product id is FW12.

35. Write SQL commands (i) to (iv) for the following tables :

TABLE : STUDENT
S NO NAME STREAM FEES AGE SEX AID
1 RAJAN KUMAR COMPUTER 750.00 17 M A1
2 DEEPA JENEJA COMPUTER 750.00 18 F A2
3 KESHAR MEHRA BIOLOGY 500.00 16 M A2
4 SACHIN SINGH ENG. DR 350.00 18 M A1
5 PRACHI ECONOMICS 300.00 19 F A3
6 NISHA ARORA COMPUTER 750.00 15 F A3
7 NEEL KUMAR ECONOMICS 300.00 16 M A1
8 SARIKA VASWANI BIOLOGY 500.00 15 F A1

TABLE: ADDRESS
AID City
Al Jaipur
A2 Bengaluru
A3 Delhi
(i) List the name of all the students, who have taken stream as COMPUTER.
(ii) To count the number of female students.
(iii) To display the number of students stream wise.
(iv) To display names of the students with corresponding cities.


o
Write the command to display all the tables in the database.
 SECTION E
36. Expertia Professional Global (EPG) is an online corporate training provider specializing in IT-related
courses. The company is establishing a new campus in Mumbai, and as a network expert, you are tasked
with analyzing the physical layout of various buildings and determining the optimal number of computers
to be installed in each location. During the planning phase, you must provide the most effective solutions
for the queries (i) to (v) that have been raised by the company..
Physical locations of the buildings of EPG

Building to building distance (in metre)

From To Distance
Administrative Building Finance Building 60
Administrative Building Faculty Studio Building 120
Finance Building Faculty Studio Building 70
Expected computers to be installed in each building

Buildings Computers
Administrative Building 20
Finance Building 40
Faculty Studio Building 120
(i) Suggest the most appropriate building, where EPG should plan to install the server.
(ii) Suggest the most appropriate building to building cable layout to connect all three buildings for efficient
communication.
(iii) Which type of network out of the following is formed by connection the computers of these three
buildings?
(a) LAN (b) MAN (c) WAN
(iv) Write the difference between LAN and MAN.
(v) Expand the following
(a) WAN (b) MAN
37. Consider the following table ORDERS :

TABLE : ORDERS
O_Id Order Date OrderPrice Customer
1 2008/11/12 1000 Hansen
2 2008/10/23 1600 Nilsen
3 2008/09/02 700 Hansen
4 2008/09/03 300 Hansen
5 2008/08/30 2000 Jensen
6 2008/10/04 100 Nilsen
(i) Write a statement to create the above table.
(ii) Write a command to change the width of Customer column to varchar(30)
(iii) Write statements to :
(a) Display the field names, their type , size and constraints .
(b) Display details of orders where orderprice is in the range 500 to 1500

(Option for part iii only)

o
(a) Write a command to increase orderprice of all orders by 15%.
(b) Name the constraint that will restrict both NULL and DUPLICATE values in the O_Id field.