CBSE class 12 computer science model paper for 2021, Exams of Computer science

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Computer Science [083] | Based on Latest CBSE Exam Pattern Xs for the Session 2021-22 Class - XII QUESTION BA TERM - 1 Mero Meta NTT NTS 1 DISTRIBUTION OF MARKS 06 DISTRIBUTION OF MARKS 05 SYLLABUS 07-10 SYLLABUS 06-09 COMPUTATIONAL TH! 12-57 COMPUTER NETWORKS 97-129 PRCT -2 DATABASE MANAGEMEN 130-158 4 | MODEL QUESTION PAPER 58-92 MODEL QUESTION PAPER 159-180 SET1 SET1L SET2 SET2 SET3 SET3 5|Page TABLE OF CONTENTS Unit lll: Database Management « Database concepts: introduction to database concepts and its need * Relational data model: relation, attribute, tuple, domain, degree, cardinality, keys [candidate key, primary key, alternate key, foreign key) Structured Query Language: introduction, Data Definition Language and Data Manipulation Language, data type (char(n}, varchar(n}, int, float, date), constraints (not null, unique, primary key), create database, use database, show databases, drop database, show tables, create table, describe table, alter table (add and remove an attribute, add and remove primary key), drop table, insert, delete, select, operators (mathematical, relational amd logical), aliasing, distinct clause, where clause, in, between, order by, meaning of null, is null, is mot null, like, update command, delete command Aggregate functions (max, min, avg, sum, count), group by, having clause, joins “Cartesian product ‘on two tables, equi-jain and natural join Interface of python with an SQ) database: connecting SQL with Python, performing insert, update, delete queries using cursor, display data by using fetchone(), fetchall[), rowcount, creating database connectivity applications 5, Practical S.No Mora | Term-1 Term-2 freet so) | [23 Marks) | [13 Merks] 1 Lab Test: 1. Python program & 6 2 2. 3-501 Queries based on one/two table(s), 2 output 4 _ 4 questions based on SO). queries Report file: T 4 3 Term — 1: Minimum 15 Python programs based on Term - 1 Syllabus Term —2: ® Minimum 3 Python programs based on Term-2 ‘Syllabus: ® SOL Queries — Minimum 5 sets using one table / twa tables. ® Minimum 2 programs based om Python - SOL Project (using concepts learntin Classes 11 and 12) & 3 5 Term — 1: Synopsis of the project to be submitted by the students (documentation only, may not submit the code during Term - 1) Term - 2: Final coding + Viva voce: (Student will be allowed to modify their Term 1 document and submit the final executable code.| Viva voce 3 2 1 8| Page 6. Suggested Practical List: Term-1 Python Programming «© Read a text file line by line and display each word separated by a #. ©) Read a text file and display the number of vowels/consonants/uppercase/lowercace characters in the file. ® Remove all the lines that contain the character ‘a’ in a file and write it to another file. ©) Create a binary file with name and roll number. Search for a given roll number and display the name, if not found display appropriate message. ©) Greate a binary file with roll number, name and marks. Input a roll number and update the marks. ©) Write a random number generator that generates random numbers between 1 and 6 (simulates a dice). ©) Create a CSV file by entering user-id and password, read and search the password for given user- id. Term-2 Python Programming ©) Write a Python program to implement a stack using list. Database Management ®) Create a student table and insert data. Implement the following SQL commands on the student table: o ALTER table toadd new attributes / modify data type,’ drop attribute © UPDATE table to modify data o ORDER By to display data in ascending / descending order o DELETE to remove tuple(s} o «GROUP BY and find the min, max, sum, count and average o Joining of two tables. © Similar exercise may be framed for other cases. © Integrate SQL with Python by importing suitable module. Database Management ©) Greate a student table and insert data. Implement the following SQL commands on the student table: ALTER table to add new attributes / modify data type,’ drop attribute UPDATE table to modify data ORDER By to display data in ascending / descending order DELETE to remove tuple(s) GROUP BY and find the min, max, sum, count and average © Similar exercise may be framed for other cases. © integrate SOL with Python by importing suitable module. 9|Page 11|Page 7. Suggested Reading Material ©) NCERT Textbook for COMPUTER SCIENCE (Class XII) © Support Materials on the CASE website. 8. Project ‘The aim of the class project is to create something that is tangible and useful using Python file handling! Python-SOL connectivity. This should be done in groups of two te three students and should be started by students at least 6 months before the submission deadline. The aim here is tofind areal world problem that is worthwhile to solve. Students are encouraged to visit local businesses and ask them about the problems that they are facing. For example, if a business is finding it hard to create invoices for filing GST claims, then students can do @ project that takes the raw data [list of transactions), groups the transactions by category, accounts for the GST tam rates, and creates invoices in the appropriate format. Students can be extremely creative here. They can use a wide variety of Python libraries to create user friendly applications such as games, software for their school, software for their disabled fellow students, and mobile applications, of course to do some of these projects, some additional learning is required; this should be encouraged. Students should know how to teach themselves. The students should be sensitised to avoid plagiarism and violations of copyright issues while working on projects. Teachers should take necessary measures for this. ¢ Precedence of operators: () Parentheses Highest ** Exponentiation ~ x Bitwise nor +x, -x Positive, Negative (Unary +, -) *(multiply), / (divide),//(floor division), %(modulus) +(add),-(subtract) & Bitwise and * Bitwise XOR | Bitwise OR <(less than),<=(less than or equal),>(greater than), >=(greater than or equal to), ==(equal),!=(not equal) is , is not not x Boolean NOT and Boolean AND v or Boolean OR Low Data type: There are following basic types of variable in as explained in last chapter: Type Description bool Stores either value True or False. int Stores whole number. float Stores numbers with fractional part. Complex Stores a number having real and imaginary part (a+bj) String Stores text enclosed in single or double quote List Stores list of comma separated values of any data type between square [ ] brackets.(mutable ) Tuple pores list of comma separated values of any data type etween parentheses ( ) (immutable) Dictionary Unordered set of comma-separated key:value pairs , within braces { } 14|Page All questions are of 1 mark. Q.No. 1. 2. 3. 10. ii. 12. 13. 14, 15. 16. 17. 18. 19. 20. Question Which of the following is a valid identifier: i. Stype ii. _type iii. Same-type iv. True Which of the following is a relational operator: i. > ii, // iii. or iv, ** Which of the following is a logical operator: i. + ii, /= iii. and iv. in Identify the membership operator from the following: i. in ii. notin iii. bothi& ii iv. Onlyi Which one is a arithmetic operator: i. not ii, ** iii. both i&ii iv. Only ii What will be the correct output of the statement : >>>4//3.0 i. 1 ii, 1.0 iii 1.3333 iv. None of the above What will be the correct output of the statement : >>> 44+2**2*10 i. 18 ii, 80 iii. 44 iv. None of the above Give the output of the following code: >>> a,b=4,2 >>> atb**2*10 i. 44 ii. 48 iii. 40 iv. 88 Give the output of the following code: >>> a,b=4,2.5 >>> a-b//2**2 i. 40 ii 4 iii. O iv. None of the above Give the output of the following code: >>>a,b,c=1,2,3 >>> a//b**c+a-c¥a i. -2 ii. -2.0 iii. 2.0 iv. None of the above If a=1,b=2 and c= 3 then which statement will give the output as : 2.0 from the following: i. >>>a%b%c+1 ii. >>>a%b%c+1.0 iii. >>>a%b%c iv. a%b%c-1 Which statement will give the output as : True from the following : i. >>>not -5 ii. >>>not 5 iii. >>>not 0 iv. >>>not(5-1) Give the output of the following code: >>>7*(8/(5//2)) i. 28 ii. 28.0 iii. 20 iv. 60 Give the output of the following code: >>>import math >>> math.ceil(1.03)+math.floor(1.03) i. 3 ii. -3.0 iii. 3.0 iv. None of the above What will be the output of the following code: >>>import math >>>math.fabs(-5.03) i. 5.0 ii. 5.03 iii. -5.03 iv . None of the above Single line comments in python begin with................... symbol. i. # i. “ iii. % iv. _ Which of the following are the fundamental building block of a python program. i. Identifier ii. Constant iii. Punctuators iv. Tokens The input() function always returns a value of ..type. i. Integer ii. float iii. string iv. Complex .. function is used to determine the data type of a variable. type() ii. id) iii. print() iv. str() The smallest individual unit in a program is known as a.. i. Token ii. keyword iii. punctuator iv. identifier 15|Page FLOW OF EXECUTION #Decision making statements in python Statement if statement if...else statement if...elif...else nested if... else statements Description An if statement consists of a boolean expression followed by one or more statements. An if statement can be followed by an optional else statement, which executes when the boolean expression is false. If the first boolean expression is false, the next is checked and so on. If one of the condition is true , the corresponding statement(s) executes, and the statement ends. It allows to check for multiple test expression and execute different codes for more than two conditions. #Iteration or Looping construct statements in python Loop for loop: for<ctrl_var>in<sequence>: <statement in loop body> else: <statement> while loop: while<test_exp>: body of while else: body of else 16|Page Description It is used to iterate/repeat ifself over a range of values or sequence one by one. The while loop repeatedly executes the set of statement till the defined condition is true. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. Which of the following is not a python legal string operation. i. ‘abe’+’aba’ ii. ‘abe’*3 iii. ‘abe’+3 iv. ‘abe’ lower() Which of the following is not a valid string operation. i. Slicing ii. concatenation iii. Repetition iv. floor Which of the following is a mutable type. i. string ii. tuple iii. int iv. list What will be the output of the following code str1="I love Python” strlen=len(str1)+5 print(strlen) i. 18 ii, 19 iii, 13 iv. 15 Which method removes all the leading whitespaces from the left of the string. i. split ii. remove() iii. IstripQ iv rstripQ It returns True if the string contains only whitespace characters, otherwise returns False. i)isspace() ii. strip) iii. islower() _ iv. isupper() It converts uppercase letter to lowercase and vice versa of the given string. i. IstripQ. ii. swapcase() iii. istitle() iv. count() What will be the output of the following code. Str="Hello World! Hello Hello’ Str.count(‘Hello’,12,25) i. 2 ii. 3 iti, 4 iv. 5 What will be the output of the following code. Str="123456” print(Str.isdigitQ)) ii. True ii. False iii. None iv. Error What will be the output of the following code. Str="python 38” print(Str.isalnum()) iii True ii. False iii. None iv. Error What will be the output of the following code. Str="pyThOn” print(Str.swapcase()) i. PYtHoN ii. pyThon iii. python iv. PYTHON What will be the output of the following code. Str=”Computers” print(Str.rstrip(“rs”)) i. Computer ii. Computers iii. Compute iv. compute What will be the output of the following code. Str="This is Meera\ pen” print(Str.isdigitQ)) i. 21 ii. 20 iii. 18 iv. 19 How many times is the word ‘Python’ printed in the following statement. s="T love Python” for ch in s[3:8]: print(‘Python’) i. lltimes ii. 8times iii. 3 times iv. 5 times 19|Page 45. 46. 47. 48. 49. 50. Which of the following is the correct syntax of string slicing: i. str_name[start:end] iii. str_name[start:step] ii. str_name[step:end] iv. str_name[step:start] What will be the output of the following code? A="Virtual Reality” print(A.replace(‘ Virtual’ ,’ Augmented’)) i. Virtual Augmented iii. Reality Augmented ii. Augmented Virtual iv. Augmented Reality What will be the output of the following code? print(“ComputerScience” split(“er”,2)) i. [“Computer”,”Science”] ui. [“Comput”,”Science”] u. [“Comput”,”erScience”] iv. [“Comput”,”er’,”Science”] Following set of commands are executed in shell, what will be the output? >>>str="hello" >>>str[:2] i. he ii. lo iii. olleh iv. hello ..........function will always return tuple of 3 elements. i. index() ii. split) iii. partition iv. stripQ What is the correct python code to display the last four characters of “Digital India” i. str[-4:] ii. str[4:] iii. str[*str] iv. str[/4:] LIST: A list is a collection of comma-separated values (items) of same or different type within square brackets. List types can be of three types: 1. Empty list 2. Long List 3. Nested List 2. Built-in Function (Manipulating Lists Function Description append() It adds a single item to the end of the list. extend() It adds one list at the end of another list insert() It adds an element at a specified index. reverse() It reverses the order of the elements in a list. index() It returns the index of first matched item from the list. len() Returns the length of the list i.e. number of elements in a list sort() This function sorts the items of the list. clear() It removes all the elements from the list. count() It counts how many times an element has occurred in a list and returns it. non) It removes the element from the end of the list or from the specified index and also returns it. 20|Page del Statement It removes the specified element from the list It is used when we know the element to be deleted, not the index of the remo) element. max() Returns the element with the maximum value from the list. min() Returns the element with the minimum value from the list. 51. Given the list L=[11,22,33,44,55], write the output of print(L[: :-1]). i. [1,2,3,4,5] ii. [22,33,44,55] iii. [55,44,33,22,11] iv. Error in code 52. Which of the following can add an element at any index in the list? i. insert() ii. append( ) iii. extend() iv. all of these 53 Which of the following function will return a list containing all the words of the given string? i. split) ii. index() iii. count iv. listQ 54. Which of the following statements are True. a. [1,2,3,4]>[4,5,6] b. [1,2,3,4]<[1,5,2,3] ce. [1,2,3,4]>[1,2,0,3] d. [1,2,3,4]<[1,2,3,2] i. a,b,d ii, acd iii, a,b,c iv. Only d 55. If 11=[20,30] 12=[20,30] 13=[‘20°,30’] 14=[20.0,30.0] then which of the following statements will not return ‘False’: a, >>>1l==12 b. >>>14>11 cc. >>>11>12.— d. >>> 12==12 i. b,c ii. a,b,c iii. a,c,d iv. ad 56. >>>11=[10,20,30,40,50] >>>12=11[1:4] What will be the elements of list 12: i. [10,30,50] ii. [20,30,40,50] _ iii. [10,20,30] iv. [20,30,40] 57. >>>l=[‘red’,’blue’] >>>1=1+ ‘yellow’ What will be the elements of list 1: i. [‘red’blue’,’yellow’] ii. [‘red’,’yellow’] iii. [‘ted’,”blue’,’yellow’] _ iv. Error 58. What will be the output of the following code: >>>1=[1,2,3,4] >>>m=[5,6,7,8] >>>n=m+1 >>>print(n) i. [1,2,3,5,6,7,8] ii. [1,2,3,4,5,6,7,8] iii. [1,2,3,4][5,6,7,8] iv. Error 59. What will be the output of the following code: >>>I=[1,2,3,4] >>>m=1*2 >>>n=m*2 >>>print(n) i [1,2,3,4,1,2,3,4,1,2,3,4] ii. [1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4] iii. [1,2,3,4][4,5,6,7] iv. [1,2,3,4] 60. Match the columns: if >>>|=list(‘computer’) Column A Column B 21|Page 71. 72. 723. 74. 75. It returns a list of values from key-value pairs in a values) dictionary et() It returns the value for the given key ,if key is not 8 available then it returns None copy( ) It creates the copy of the dictionary. len() Returns the length of the Dictionary i.e. number of key:value pairs in a Dictionary fromkeys( ) It is used to create dictionary from a collection of ys keys(tuple/list) clear( ) It removes all the elements from the Dictionary. It sorts the elements of a dictionary by its key or SEEK) values. me * epitem6) It removes the last item from dictionary and also Pop returns the deleted item. mar) Returns the key having maximum value in the Dictionary. : Returns the key having minimum value in the min() Dictionary. Which of the statement(s) is/are correct. i. Python dictionary is an ordered collection of items. ii. Python dictionary is a mapping of unique keys to values iii. Dictionary is mutable. iv. All of these. beceeeees function is used to convert a sequence data type into tuple. i. List() ii tuple) iti TUPLE iv. tup() It tup=(20,30,40,50), which of the following is incorrect i. print(tup[3]) ii. tup[2]=55 iii. print(max(tup)) iv. print(len(tup)) Consider two tuples given below: >>>tup1=(1,2,4,3) >>>tup2=(1,2,3,4) What will the following statement print(tup1<tup2) i. True ii. False iii. Error iv. None of these Which function returns the number of elements in the tuple i. len() ii. max() iii. min() iv. count( ) 24|Page 76. 77. 78. 79. 80. 81. 82. 83 84 85 86 87 88 89 91 Which function is used to return a value for the given key. i. len() ii. get() iii. keys() iv. None of these Keys of the dictionary must be i. similar ii. unique iii. can be similar or unique iv. All of these Which of the following is correct to insert a single element in a tuple . i. T=4 ii. T=(4) iii. T(4,) iv. T=[4,] Which of the following will delete key-value pair for key=’red’ form a dictionary D1 i. Delete Dl(“‘ted”) ii. del. D1(“‘red”) iti. del D1[“red”] iv. del D1 Which function is used to remove all items form a particular dictionary. i. clear() ii. pop() iii. delete iv. rem() In dictionary the elements are accessed through i. key ii. value iii. index iv. None of these Which function will return key-value pairs of the dictionary i. key() ii. values( ) iii. items() iv. get() Elements in a tuple can be of ............. type. i. Dissimilar ii. Similar iii. bothi & ii iv. None of these To create a dictionary , key-value pairs are separated by................ i. (@) i. (,) iii © iv. (/) Which of the following statements are not correct: a. An element in a dictionary is a combination of key-value pair b. A tuple is a mutable data type c. We can repeat a key in dictionary d. clear( ) function is used to deleted the dictionary. i. a,b,c ii. b,c,d iii. b,c,a_ iv. a,b,c,d Which of the following statements are correct: a. Lists can be used as keys in a dictionary b. A tuple cannot store list as an element c. We can use extend() function with tuple. d. We cannot delete a dictionary once created. i. a,b,c ii. b,c,d iii. b,c,a_ iv. None of these Like lists, dictionaries are................/ which mean they can be changed. i. Mutable ii. immutable iii. variable iv. None of these To create an empty dictionary , we use i. d=[] ii. d=() iii, d={} iv. d=<> To create dictionary with no items , we use ii. Dict _ ii. dict() iii. d=[] iv. None of these What will be the output >>>d1=({‘rohit’ :56,”Raina”:99} >>>print(“Raina” in d1) i. True ii. False iii. No output iv. Error Rahul has created the a tuple containing some numbers as >>>t=(10,20,30,40) now he wants to do the following things help him 1. He want to add a new element 60 in the tuple, which statement he should use out of the given four. 25|Page 92 93 94 95 96 97 98 99 i. >>>t+(60) ii. >>>t+ 60 iii. >>>t + (60,) iv. >>>t + (©60’) Rahul wants to delete all the elements from the tuple, which statement he should use i. >>>delt ii. >>>t.clear() iii. >>>t.remove() iv. >>>None of these Rahul wants to display the last element of the tuple, which statement he should use i. >>> tdisplay() ii. >>>tpop() iii. >>>tL-1] iv. >>>tlast() Rahul wants to add a new tuple t! to the tuple t, which statement he should use i. >>>t+tl ii. >>>t.add(tl) iii. >>>e*tl iv. None of these Rahul has issued a statement after that the tuple t is replace with empty tuple, identify the statement he had issued out of the following: i. >>> delt ii. >>>t= tuple() iii. >>>t=TupleQ iv. >>>delete t Rahul wants to count that how many times the number 10 has come: i. >>>t.count(10) ii. >>>t[10] iii. >>>count.t(10) iv. None of these Rahul want to know that how many elements are there in the tuple t, which statement he should use out of the given four i. >>>t.count() ii >>>len(t) >>>count(t) iv. >>>t.sum() >>>t=(1,2,3,4) Write the statement should be used to print the first three elements 3 times i. >>>print(t*3) ii. >>>0*3 iii. >>>t[:3]*3 iv. >>>t+t Match the output with the statement given in column A with Column B 1. >>>tuple({10,20,30]) a. >>> (10,20,30) 2. >>>(“Tea”,)* 3 b. >>>2 3. >>>tuple(“Item”) c. >>> ('Tea’, 'Tea’, 'Tea') 4. >>>print(len(tuple({1,2]))) d. >>> (T, 't’,'e’, 'm') i. 1-b,2-c,3-d,4-a ii. 1-a,2-c,3-d,4-b iii. 1-c,2-d,3-a,4-a iv. 1-d,2-a,3-b,4-c 26|Page Built-in Functions Function eval() min() and max() abs() type() round() len() range() Description It is used to evaluate the value of a string and returns numeric value Both can take two or more arguments and returns the smallest and largest value respectively. It returns the absolute value of a single number. It is used to determine the type of variable. It returns the result up to a specified number of digit . Returns the length of an object. It is used to define a series of numbers. Functions form math module ceil(x) floor(x) pow(x,y) sqrt(x) It returns the smallest integer that is greater than or equal to x. It returns the largest integer that is less than or equal to x. It returns the value of x” , where x and y are numeric expressions, and returns the output in floating point number. Returns the square root of x. Functions from random module random() randrange() choice() shuffled It generates a random number from 0 to 1. It generates an integer between its lower and upper argument. By default the lower argument is 0 and upper argument is 1 It is used for making a random selection from a sequence like list, tuple or string. It is used to shuffle or swap the contents of a list. 101 A function in python begins with which keyword? i. void ii. return iii. int iv. Def 102 Name the statement that sends back a value from a function i. print ii. input iii. return iv. None 103 What is the output of the program given below: x=50 def func(x): x=2 func(x) print(‘x is now’x) 29|Page 104 105 106 107 108 109 110 iil 112 113 i. x is now 50 iii. xisnow 2 ii. xisnow 100 iv. Error What is the output of the program given below: import random x = random.random() y= random.randint(0,4) print(int(x),”:”, y+int(x)) i. 0:0 iii, 2:4 ii. 1:6 iv. 0:5 def cal(a,b,c): return a*3,b*3,c*3 val=cal(10,12,14) print(type(val)) print(val) i. (30, 24, 28] iii. [30,36,42] ii. [10, 20, 30] iv. [10,12,14] What is the output of the expression:round(4.576) i. 45 ii. 5 iii, 4 iv. 4.6 What is the output of the function shown below? import math abs(math.sqrt(25)) i. Error ii. -5 iii, 5 iv. 5.0 What is the output of the functions shown below?>>min(max (False,-3,-4), 2,7) i. 2 ii. False iii. -3 iv. -4 What are the outcomes of the function shown below? >»>x=3 >>>eval('x**2') i. Error ii, 1 iii, 9 iv. 6 Which of the following functions does not throw an error? i. ord() ii. ord ‘) iii. ord@’) iv. ord(‘”’”) What is the output of below program? def say(message, times = 1): print(message * times , end=" ‘) say(‘Hello and’) say(‘World', 5) i. Hello and WorldWorldWorldWorldWorld ii. Hello and World 5 iii. Hello and World, World, World, World, World iv. Hello and HelloHelloHelloHelloHello What is a variable defined inside a function referred to as? i. A global variable ii. A volatile variable iii. A local variable iv. An automatic variable How many keyword arguments can be passed to a functionin a single function call? i. zero ii. one iii. zeroormore iv. one or more 30| Page 114 How are required arguments specified in the functionheading? i. identifier followed by an equal to sign and the default value ii. identifier followed by the default value within backticks (“) iii.identifier followed by the default value within squarebrackets ([ ]) iv. identifier 115 What is returned by >>> math.ceil(3.4)? i. 3 ii, 4 iii, 4.0 iv. 3.0 116 What is the value returned by >>> math.floor(3.4) a) ii. 4 iii. 4.0 iv. 3.0 117 What is returned by >>> math.ceil(-3.4)? ii. 3 ii, 4 iii, 4.0 iv. -3 118 What is the value returned by >>> math.floor(-3.4) ii, 3 ii. -4 iii, 4.0 iv. 3.0 119 What is displayed on executing print(math.fabs(-3.4))? i -3.4 ii. 34 iii. 3 iv. -3 120 What is output of print(math.pow(3, 2))? i. 9 ii. 9.0 iti, None iv. None of these 121 What is the value of x if x = math.sqrt(4)? i. 2 ii. 2.0 iii. (2, -2) iv. (2.0, -2.0) 122 To include the use of functions which are present in the random library, we must use the option: i. import random iii. random.h ii. import.random iv. random.random 123 What is the output of the code shown below? import random random.choice(2,3,4) i. An integer other than 2,3 and 4 ii. Either 2, 3 or 4 iii. Error iv. 3 only 124 What is the output of the function shown below (random module has already been imported)? >>>random.choice(‘sun') i. sun ii. u iii. either s,u orn iv. Error 125 What is the output of the function shown below if the random module has already been imported? >>>import random >>>random.randint(3.5,7) i. Error ii. Any integer between 3.5 and 7, including 7 iii. Any integer between 3.5 and 7, excluding 7 v. The integer closest to the mean of 3.5 and 7 126 Which type of elements are accepted by random.shuffle()? i. strings ii. lists iii. tuples iv. integers ....keyword is used to define a function. Void ii. func iii. def iv. None 127 128 Which of the following statements are True out of the given below: 31|Page 120 |ii [121 {ii | 122 fi 123 |ii | 124 [iii | 125 |ii | 126 | ii 127 | iti [128 |ii | 129 | iti | 130 |i 131 | iti | 132 [iv | 133 | iii 134 |iv | 135 |iii | 136 |i 137 |i 138 |i 139 | iii | 140 |ii 141 ji 142 |iii | 143 {ii | 144 Jit [145 {ii | 146 [iv | 147 | iii Data File Handling Key Points of Data File Handling File:- A file is a collection of related data stored in computer storage for future data retrieval. Data files can be stored in two ways: 1. Text Files: Text files are structured as a sequence of lines, where each line includes a sequence of characters. 2. Binary Files: A binary file is any type of file that is not a text file. WORKING WITH TEXT FILES: Basic operations with files: a. Read the data from a file b. Write the data to a file c. Append the data to a file d. Delete a file a. Read the data from a file: There are 3 types of functions to read data from a file. -read( ), readline( ), readlines( ) Binary files are used to store binary data such as images, video files, audio files etc. They store data in the binary format (0‘s and 1‘s). In Binary files there is no delimiter for a line. To open files in binary mode, when specifying a mode, add 'b' to it. Pickle module can be imported to write or read data in a binary file. CSV (Comma Separated Values) is a file format for data storage which looks like a text file. The information is organized with one record on each line and each field is separated by comma. CSV File Characteristics * One line for each record * Comma separated fields « Space-characters adjacent to commas are ignored * Fields with in-built commas are separated by double quote characters. Compare text files, binary files and csv files and write pros and cons of each of them. Text Files Binary Files CSV Files It is very common It is capable to handle format and platform 1 textual data. It is capable to handle large file. independent. It consists of series of lines It consists of plain text of a set of letters, numbers It consists of data with a specific pattern | with a list of data witha 2 or symbols (String) without any delimiter. delimiter. Any text editors like No specific programs can be used to It can be read using text notepad can be used to read | read them, python provides functions to editors like notepads and 3 them. read data. spreadsheet software. It terminates a line automatically when the delimiter is not used 4 Every line ends with EOL. There is no specific EOL character. after data. 34|Page MCQs on Data File Handling 1 Every file has its own identity associated with it. Which is known as — a. icon b. extension c. format d. file type 2 Which of the following is not a known file type? a. .pdf s Jpg . mp3 ° . xp . In fFopen(“data.txt”, “1”), r refers to . File handle wa p . File object . File Mode Buffer . EOL stands for . End Of Line . End Of List . End of Lines . End Of Location Fane eo Pp we . Which of the following file types allows to store large data files in the computer memory? . Text Files . Binary Files . CSV Files op . None of these an a . Which of the following file types can be opened with notepad as well as ms excel? . Text Files s Pp . Binary Files . CSV Files None of these . Which of the following is nor a proper file access mode? . close - read Gen and c. write d. append sb] Page 8. To read 4th line from text file, which of the following statement is true? a. dt = f.readlines();print(dt[3]) b. dt=f.read(4) ;print(dt[3]) c. dt=f.readline(4);print(dt[3]) d. All of these 9 Which of the following function flushes the files implicitly? a. flushQ) b. close() c. open() d. fflush() 10. Which of the following functions flushes the data before closing the file? a. flushQ) b. close() c. open() d. fflush() 11. In F=open("MyFile.txt") , name of file object is a.open b.MyFile.txt c.F d.F=open() 12. Default EOL character in Python. a. ‘WW? b. ‘Wr’ c. d. ‘Wt 13. Which of the following is not a file extension for text files? a. .txt b. .ini c, rtf d. .DAT 14. What is the first thing to do before performing any functions on a text file? a. Import modules b. Open file c. Read file d. Print the name of the file 36|Page b. readline( ) c. output( ) d. Input( ) 33. Which function is used to remove the given character from trailing end i.e. right end? a. strip() b. remove( ) c. Istrip() d. rstrip() 34. Sometimes the last lap of data remains in buffer and is not pushed onto disk until a operation is performed. a. dump( ) b. close() c. load( ) d. open( ) 35. The position of a file-pointer is governed by the. a. File mode b. append mode c. write mode d. open mode 36. In which mode the file must exist already, otherwise python raises an error? a. read mode b. write mode c. binary mode d. None of these 37. What is the prefix r stands for in file path? a. raw string b. read c. write d. append 38. In which mode if the file does not exist, then the file is created? a. read write mode b. read mode c. write mode d. All of these 39. Which option is correct about this program? f=open(“ss.txt”,”"wb”) print(“Name of the file:”,f.name) f.flush() f.close() a. Compilation error b. Runtime error c. No output d. Flushes the file when closing them 40. What is the output of the following? import sys sys.stdout.write(‘Hello\n’) 39|Page sys.stdout.write(‘Python\n’) a. error b. Runtime error c. Hello Python d. Hello Python 41. Which function is used to read all the characters in text files? a. read( ) b. readcharacters( ) c. readall( ) d. readchar( ) 42. Which function is used to read all the lines? a. read( ) b. readall( ) c. readlines( ) d. readline( ) 43. In which format does the readlines( ) function give the output? a. Integer type b. list type c. string type d. tuple type 44, In which format does the read( ) function give the output? a. Integer type b. string type c. list type d. tuple type 45. Which function is used to write a list of strings in a file? a. writestatement() b. writelines() c. writefulline(Q) d. writeline() 46. Which function is used to write all the characters? a. writechar() b. writecharacters() c. write() d. writeall() 47. What is the correct syntax of open() function? a. file=open(file_name[,access_mode][,buffering]) b. fileobject=open(file_name[,access_model][,buffering]) c. fileobject=filename.open() d. none of the mentioned 48.In file handling, what does means “1”, “a”? a. append, read 40|Page b. read, append c. read, add d. None of the mentioned 49.The default file open mode is... a.w bert c. w+ dr 50. What is the difference between r+ and w+ modes? a. Inr+ mode, file length truncates to zero. b. In w+ mode, file length truncates to zero either file exists or not. c. No difference d. Depends on the operating system 51. A file maintains a which tells the current position in the file where writing or reading will take place. a, line b. file pointer c. list d. order 52. Which of the following statements is true regarding the opening modes of a file? a. While opening a file for reading, if the file does not exist, an error occurs. b. While opening a file for writing ,if the file does not exist, an error occurs. c. While opening a file for reading, if the file does not exist, a new file is created. d. None of the above. 53.To force python to write the contents of file buffer on to storage file......... method may be used. a. buffer() b. flush() c. close() d. write() 54. Which of the following statements are true? a) When you open a file for reading, if the file does not exist, an error occurs. b) When you open a file for writing, if the file does not exist, a new file is created. c) When you open a file for writing, if the file exists, the existing file content is overwritten with the new content. d) All of the these 55.To read the next line of the file from a file object f1, we use: a) fl.read(2) b) fl .read() c) fl.readline() d) fl.readlines() 41|Page Q7. What is the process of converting a byte stream back to the original structure called? a. append b. txt-file c. Unpickling d. None of these. Q8. Which module is used to store data into python objects with their structure? a. pickle b. binary files c. unpickle d. None of these Q9. What is pickle.dump()? a. dump() function is used to store the object data to the file. b. It is used to read c. append d. None of these Q10. Which one of the following is the correct statement? pickle import import - pickle import pickle d. None of the above Q11. Which is the valid syntax to write an object onto a binary file opened in the write mode? ese pickle.dump(<object to be written>, <file handle of open file>) pickle.dump(<file handle of open file>, <object to be written>) dump.pickle(<object>, <file handle>) None of the above aes Q12. Which method is used for object serialization? a. Pickling b. Unpickling c. None of the above d. All of the above Q13. Which method of pickle module is used to read from a binary file? dump() load() All of the above None of the above aoge 44|Page Q14.Which method is used for object deserialization? Pickling Unpickling All of the above d. None of the above Q15.Which of the following is the correct syntax to read from a file using load function? eoP pickle.load(<filehandle>) <object> - load.pickle(<filehandle>) <object> - pickle.load(<filehandle>) All of the above ae oe Q16. Which method of pickle module is used to write onto a binary file? a. dump() b. load() c. All of the above d. None of the above Q17. Which of the following file modes open a file for reading and writing both in the binary file? r rb rwb rb+ aoge Q18.Which of the following file modes that opens a file for reading and writing both and overwrites the existing file if the file exists otherwise creates a new file ? wb+ rwb rb aose Q19. Which of the following file modes opens a file for appending and reading in a binary file and moves the files pointer at the end of the file if the file already exists or creates a new file? aa b. .at c. .ab+ d. .ab Q20.Which of the following file modes will not delete the existing data in binary file? a. .wb b. ww Cc. a d. .ab 45|Page ANSWER KEY 1-A 6-A I-A 16-A 2-A 7-C 12-A 17-D 3-D 8-A 13-B 18-B 4-A 9-A 14-B 19-C 5-C 10-C 15-C 20-D CSV FILES Ql is a file format which stores records separated by comma. a. .tsv b. .csv Cc. py d. .bin Q2.The CSV files can be operated by software. a. Spreadsheet b. Notepad c. MS Excel d. All of the above Q3.When you read csv file using csv.reader() function it returns the values in object. a. dictionary b. tuple c. nested list d. sets Q4.CSV module allows to write multiple rows using function. a. writerows( ) b. writerow( ) c. writer() d. None of the above Q5.Which of the following parameter needs to be added with open function to avoid blank row followed file each row in CSV file? delimiter newline writer, delimiter file object Bo oP 46|Page 3. Data structure can be of two type’s namely. a. SImple and Compound b. SImple and Nested c. Sequential and random d. All of the above 4. Array or linear list comes under the category of. a. SImple Data Structure b. Compund Data Structure c. random d. None of these 5. Compound Data structure can be & a. Sequential and random b. Simple & Nested c. Linear & Non Linear 6. The examples of Linear Data Structures are a. Stacks,Queues,Linked list b. int,float,complex c. Operators,tokens,punctuators 7. Stacks follows, order a. FIFO (First In First Out ) b. LIFO (Last In First Out) c. Random 8. Queue follows. order a. FIFO (First In First Out ) b. LIFO (Last In First Out) c. Random 9. Main Operations in Stacks are called a. Insertion and deletion b. append and insertion c. Push and Pop 10. Main Operations in Queue are called a. Insertion and deletion b. append and insertion c. Push and Pop 11. In Stack Insertion and deletion of an element is done at single end called a. Start b. Last c. Top d. Bottom 49|Page 12 In stack we cannot insert an element in between the elements that are already inserted. a. True b. False 13. The process of visiting each element in any Data structure is termed as a. Visiting b. Searching c. Traversing d. Movement 14. While implementing Stack using list when we want to delete element we must use pop function as, a. list.pop(pos) b. list.pop(0) c. list.popQ 15. Arranging elements of a data structure in increasing or decreasing order is known as. a. Searching b. Arrangement c. Sorting d. Indexing 16. Searching of any element in a data structure can be done in 2 ways and a. Sequential and random b. linear and non linear c. linear and binary 17. is an example of nonlinear data structure a. Stack b. Queue c. Sorting d. Tree 18. In a stack, if a user tries to remove an element from empty stack it is called a. Underflow b. Empty c. Overflow d. Garbage Collection 19. What is the value of the postfix expression 6 3 2 4 +—* a 1 b. 40 c. 74 d. -18 50| Page 20. If the elements “A”, “B”, “C” and “D” are placed in a stack and are deleted one at a time, in what order will they be removed? ABCD DCBA DCAB ABDC aecge 21. Which of the following data structure is linear type? a. Stack b. Array c. Queue d. All of the above 22. The postfix form of the expression (A+ B)*(C*D- E)*F/G is? a. AB+CDE*-*F*G/ b. AB+CD*E - FG /** c. AB+CD* E-F**G/ d. AB+CD* E- *F*G/ 23. The postfix form of A*B+C/D is? *AB/CD+ AB*CD/+ A*BC+/D ABCD+/* aecep 24. Which of the following statement(s) about stack data structure is/are NOT correct? Stack data structure can be implemented using linked list New node can only be added at the top of the stack Stack is the FIFO data structure The last node at the bottom of the stack has a NULL link 1.B 2.B 3.A 4.A 5.C 6.A 7B 8.A 9.C 10.A ke 12.A 13.C 14.C 15.C 16.C 17.D 18.A 19.D 20.B 21.D 22.B 23.B 24.C 25 51| Page y. Choose the function name that should be used in the blank space of line marked as Statement-5 to create the desired CSV File? a) dump() b) load( ) c) writerows( ) d) writerow( ) Correct Answer: c) writerows( ) 2: Amritya Seth is a programmer, who has recently been given a task to write a python code to perform the following binary file operations with the help of two user defined functions/modules: a. AddStudents() to create a binary file called STUDENT.DAT containing student information — roll number, name and marks (out of 100) of each student. b. GetStudents() to display the name and percentage of those students who have a percentage greater than 75. In case there is no student having percentage > 75 the function displays an appropriate message. The function should also display the average percent. He has succeeded in writing partial code and has missed out certain statements, so he has left certain queries in comment lines. You as an expert of Python have to provide the missing statements and other related queries based on the following code of Amritya. Answer any four questions (out of five) from the below mentioned questions. import pickle def AddStudents(): #1 statement to open the binary file to write data while True: Rno = int(input("Rno :")) Name = input(""Name : ") Percent = float(input("Percent :")) L = [Rno, Name, Percent] #2 statement to write the list L 54|Page into the file Choice = input("enter more (y/n): ") if Choice in "nN": break F.close() def GetStudents(): Total=0 Countrec=0 Countabove75=0 with open("STUDENT.DAT","rb") as F: while True: try: #3 statement to read from the file Countrec+=1 Total+=R[2] if R[2] > 75: print(R[1], " has percent = "R[2)) Countabove75+=1 except: break if Countabove75==0: 55| Page print(""There is no student who has percentage more than 75") average=Total/Countrec print(""average percent of class = ",average) AddStudents( ) GetStudents( ) i. Which of the following commands is used to open the file “STUDENT.DAT” for writing only in binary format? (marked as #1 in the Python code) a. F= open("STUDENT.DAT",'wb') b. F= open("STUDENT.DAT",'w') c. F= open("STUDENT.DAT",'wb+') d. F= open("STUDENT.DAT",'w+') Correct Answer: a. F= open("STUDENT.DAT",'wb') ii. Which of the following commands is used to write the list L into the binary file, STUDENT.DAT? (marked as #2 in the Python code) a. pickle.write(L,f) b. pickle.write(f, L) c. pickle.dump(L,F) d. f=pickle.dump(L) Correct Answer: c. pickle.dump(L,F) iii. Which of the following commands is used to read each record from the binary file STUDENT.DAT? (marked as #3 in the Python code) a. R = pickle.load(F) b. pickle.read(r,f) c. r= pickle.read(f) d. pickle.load(r,f) Correct Answer: a. R = pickle.load(F) 56|Page b)Generate any number between 0 to 4(including both) c)Generate any number between 0 to 5(including both) 17 Which of the following is valid variable name:- a)Student name b)3Number c)Fname% d)Block_number 18 | What will be the output after the following statements? a= [0, 1, 2, 3] del a[:] print(a) a)None b)] c)[0, 1, 2, 3] d)NameError 19 | What will be the output after the following statements? x=27 y=9 while x < 30 and y< 15: x=xt+1 yeyt. print(x,y) a) 2611 b) 25 11 c) 30 12 d) 26 10 20 What will the following code produce? TA ‘kvs’,’rpr’] T1=range(len(T)) for iin Tl: T[i]=T[i]-upperd) print(T) a)[‘KVS’,’RPR’] b)[‘kvs’,’rpr’] o)[‘Kvs’,’Rpr’] d)Error 21 Find out the type of error if any- ifv <5: print(‘KVS”) else: print(‘CBSE”) a)No Error b)Declaration of v c): with else not required _d)Indentation Error 22 Consider square numbers defined as follows: compute(1) = 1 compute(N) = compute(N-1) + 2N-1 According to this definition, what is compute (3)? a)compute(3) = compute(2) +compute(1) b)compute(3) = compute(2) -2*3+1 b)compute(3) = compute(2) + 2*3-1 d)compute(3) = compute(3) +2*3-1 23 When you open a file for writing, if the file does not exist, an error occurs.(True/False) 24 The relative path for a file always remains same even after changing the directory.(True/False) 25 The value of the expressions 4/(3*(4-2)) and 4/3*(4-2) is the same.(True/False) 26 The command to merge the dictionary Book with Library the command would be: a) d=Book+Library b) print(Book+Library) c)Book.update(Library) d)Library.update(Book) 27 Identify the correct option to add new value 50 to existing tuple T T = (11,22,33,44,55) a)T =T +66 b)T=T+66 c)T =T + (66,) d)T=T + (66) 28 Find and write the output of the following python code: a=10 def callQ): global a a=15 b=20 print(a) call() a)25 b)35, e)15 d)10 29 Which of the following Python codes will result in an error? object = ‘a’ 59|Page a)pickle.dumps(object) b)pickle.dumps(object,3) c)pickle.dump s(object,3,True) d)pickle.dumps(‘a’,2) 30 ifisa and roll_no is a/an. 31 if a= [5,4,3,2,2,2,1], evaluation of the expressiona[a[a[a[2]+1]]]: a)3 b)4 c)5 dj2 32 What is the output of the following program : print( 0.1 + 0.2 == 0.3) a)True b)False c)Machine Dependent __d)Error 33 What will be the output after the following statements? x=0 y=4 while x + y < 10: print(x, end=' ') x+=2 a0 246 b)024 c)02 d)0248 34 apple ="red’ def fruit(): pineapple=’ green’ In above code apple is a variable while pineapple is a variable. 35 Which of the following is the use of id() function in Python? a) Id returns the identity of the object b) Every object doesn’t have a unique ID c) All of the mentioned d) None of the mentioned Section-II (Case Study Based Question) 36 Rohit, a student of class 12th, is learning CSV File Module in Python. During examination, he has been assigned an incomplete python code (shown below) to create a CSV File 'Student.csv' (content shown below). Help him in completing the code which creates the desired CSV File. CSV File 1,AKSHAY,XII,A 2,ABHISHEK,XILLA. 3,ARVIND,XII,A 4,RAVLXIL,A 5,ASHISH,XILA Incomplete Code import. #Statement-1 fh = open( newline=") #Statement-2 stuwriter = csv. #Statement-3 data = [] header = ['ROLL_NO', 'NAME', 'CLASS', 'SECTION'] data.append(header) for i in range(5): roll_no = int(input("Enter Roll Number : ")) name = input("Enter Name : ") Class = input("Enter Class :") section = input("Enter Section : ") rec =[ ] #Statement-4 data.append(rec) stuwriter. (data) #Statement-5 fh.close() Answer any four of the following questions. Identify the suitable code for blank space in line marked as Statement-1 a) csv file b) CSV c) csv d) Csv ii) Identify the missing code for blank space in line marked as Statement-2? a) "School.csv","w" b) "Student.csv","w" c) "Student.csv","r"—d) "School.csv","r' iii) Choose the function name (with argument) that should be used in the blank space of line marked as Statement-3 a) reader(fh) b) reader(MyFile) c) writer(fh) d) writer(MyFile) 60|Page iv) Identify the suitable code for blank space in line marked as Statement-4. a) 'ROLL_NO', 'NAME’, 'CLASS', 'SECTION' b) ROLL_NO, NAME, CLASS, SECTION c) 'roll_no','name'’,'Class','section’ d) roll_no,name,Class,sectionc) co.connect() vy) Choose the function name that should be used in the blank space of line marked as Statement-5 to create the desired CSV File? a) dump() b) load() c) writerows() d) writerow() 37 | Your teacher has given you a method/function FilterWords() in python which read lines from a text file NewsLetter.TXT, and display those words, which are lesser than 4 characters. Your teachers intentionally kept few blanks in between the code and asked you to fill the blanks so that the code will run to find desired result. Do the needful with the following python code. def FilterWords(): c=0 file=open('NewsLetter.TXT’, * ') #Statement-1 line = file. #Statement-2 word #Statement-3 for c in word: if : #Statement-4 print(c) #Statement-5 FilterWords() Answer any 4 of the following questions. i) Write mode of opening the file in statement-1? aa b. ab cw dir ii) Fill in the blank in statement-2 to read the data from the file. a. File.Read() b. file.read() c. read.lines( ) d. readlines( ) iii) | Fillin the blank in statement-3 to read data word by word. a. Line.Split() b. Line.split() c. line.split() d. split.word() iv) Fill in the blank in statement-4, which display the word having lesser than 4 characters. a. len(c) == b. len(c)<4 c. len ( )= =! d. len ( )==3 v) Fill in the blank in Statement-5 to close the file. a. file.close() b. File.Close() c. Close() d. end() 61| Page KENDRIYA VIDYALAYA SANGATHAN, RAIPUR REGION Term-I Examination — 2021-22 odel Question Paper-Set-2 Class- XII, Subject - Computer Science (083) Duration: 90 mins. MM: 35 General Instructions to the Examinee: This question paper contains two parts A and B. Each part is compulsory. Both Part A and Part B have choices. Part-A is having MCQs (Attempt 27 out of 35 questions). Part- B has two Case based questions. a. Each case study has 4 case-based subparts. b. An examinee is to attempt any 4 out of the 5 subparts. 5. All programming questions are to be answered using Python Language only. AYN Part-A (Attempt any 27 questions from question no 1 to 35.) 1. What possible output(s) are expected to be displayed on screen at the time of 1 execution of the program from the following code? from random import randint LST=[5, 10, 15,20,25,30,35,40,45,50,60,70] first = randint(3,8) — 1 second = randint(4,9) — 2 third = randint(6,11) — 3 print(LST[first],"#", LST[second],"#", LST[third],"#") a) 20#25#25# b) 30#40#70# c) 15#60#70# d) 35#40#60# 2. Specify the maximum values that can be assigned to each of the variables first, 1 second and third in the code given in Question no. | - a) 6, Second: 6, Third: 7 b) 7, Second: 7, Third: 8 c) 3, Second: 4, Third: 6 d) First: 8, Second: 8, Third: 9 3. Which of the following is not a valid identifier name in Python? 1 (a) First_Name (b) _Area (c)2nd_num (d)While 4, Which statement is correct for dictionary? 1 (a) A dictionary is an ordered set of key:value pair (b) each of the keys within a dictionary must be unique (c) each of the values in the dictionary must be unique (d) values in the dictionary are immutable 5. Identify the valid declaration of Record: 1 Record=(1342, “Pooja” , 45000, “Sales”) (a) List (b) Tuple (c) String (d) Dictionary 6. Which of the following functions do we use to write data in a binary file? 1 (a) writer() (b) output( ) (©) dump( ) (d) send() 64|Page 10. 11. 12. 13. 14. 65|Page Which operator is used for replication? (a) + (b) % (c) * (d) / Which of the following functions generates an integer? (a) uniform( ) (b) randint( ) (c) random( ) (d) None of the above Consider the tuple in python named DAYS=( “SUN”, “MON”, “TUES”). Identify the invalid statement(s) from the given below statements: (a) S=DAYS[1] (b) print(DAYS[2]) (c) DAYS[0}— “WED” (d) LIST=list(DAYS) tl=(2,3,4,5,6) print(tl.index(4)) Output will be — (a) 4 (b) 5 (c) 6 (d) 2 Which of the following statements correctly explain the function of tell() method? (a) tells the current position within the file. (b) tell the name of file. (c) move the current file position to a different location. (d) it changes the file position only if allowed to do so else returns an error. Which of the following statements correctly explain the function of seek() method? (a) tell the current position within the file. (b) indicate that the next read or write occurs from that position in a file. (c) determine if you can move the file position or not. (d) move the current file position to a different location at a defined offset. Which of the following command is used to open a file “c:\temp.txt” in read- mode only? (a) infile = open(“c:\temp. txt”, “1’”) (b) infile = open(“c:\\temp.txt”, “1’”) (c) infile = open(file = “c:\temp.txt”, “1+’”) (d) infile = open(file = “c:\\temp. txt”, “1+”) Which of the following command is used to opena file “c:\temp.txt” in write- mode only? (a) outfile = open(“c:\temp.txt”, “w’”) (b) outfile = open(“c:\\temp.txt”, “w”) (c) outfile = open(file = “c:\temp.txt”, “w+”) (d) outfile = open(file = “c:\\temp.txt”, “w+”) 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 66|Page Which of the following command is used to open a file “c:\temp.txt” in append-mode? (a) outfile = open(“c:\\temp.txt”, “a’”’) (b) outfile = open(“c:\\temp.txt”, “rw”) (c) outfile = open(“c:\temp.txt”, “w+”) (d) outfile = open(“c:\\temp.txt”, “1+”) Which of the following commands can be used to read “n” number of characters from a file using the file object <file>? (a) file.read(n) (b) n = file.read() (c) file.readline(n) (d) file.readlines() Which of the following commands can be used to read the entire contents of a file as a string using the file object <tmpfile>? (a) tmpfile.read(n) (b) tmpfile.read() (c) tmpfile.readlineQ) (d) tmpfile.readlines() Which of the following commands can be used to read the remaining lines in a file using the file object <tmpfile>? (a) tmpfile.read(n) (b) tmpfile.read() (c) tmpfile.readlineQ) (d) tmpfile.readlines() Which of the following statement is False regarding the opening modes of a file? (a) When you open a file for reading, if the file does not exist, an error occurs. (b) When you open a file for reading, if the file does not exist, the program will open an empty file. (c) When you open a file for writing, if the file does not exist, a new file is created. (d) When you open a file for writing, if the file exists, the existing file is overwritten with the new file. Which module is required to use built in function dump() (a) Math (b)flush (c)pickle (d)csv Which of the following function is used to write data in binary mode? (a) write (b)output (c)dump (d)send To read 2 characters from file object {1 command should be (a)fl.read(2) (b)f1 .readQ) (c)f1 readlineQ) (d) f 1 .readlines() To get byte position from the beginning of file, function used is - (a)seek (b)tell (c)read (d)write The file pointer, used to go to particular position (a)seek (b)tell (c)read (d)write 37. 69|Page @ (ii) (iii) (iv) (vy) Write mode of opening the file in statement-1? (ay A (b) Ab () W (dr Fill in the blank in statement-2 to read the data from the file. (a) File.Read() (b) file.readQ) (c) read.lines( ) (d) readlines( ) Fill in the blank in statement-3 to read data word by word. (a) Line.Split() (b) Line.split() (c) line.splitO (d) split.word() Fill in the blank in statement-4, which display the word having exactly 5 characters. (a) len(c) == (b) len(c)<5 (c) len ()==5 (d) len ()==6 Fill in the blank in Statement-5 to close the file. (a) file.close() (b) File.CloseQ) (c) Close() (d) end() Snigdha is making a software on “Countries & their Capitals” in which various records are to be stored/retrieved in CAPITAL.CSV data file. It consists some records (Country & Capital). She has written the following code in python. Asa programmer, you have to help her to successfully execute the program. import # Statement-1 def AddNewRec(Country,Capital): # Fn. to add a new record in CSV file fopen(“CAPITAL.CSV”, # Statement-2 fwriter=csv.writer(f) fwriter.writerow([Country,Capital]) # Statement-3 def ShowRec(): # Fn. to display all records from CSV file with open(“CAPITAL.CSV”,"r”) as NF: NewReader=csv.. (NF) # Statement-4 for rec in NewReader: print(rec[0], “#”, rec[1]) AddNewRec(“INDIA”, “NEW DELHI”) AddNewRec(“CHINA”, “BEINJING”) ShowRec() # Statement-5 70|Page (i) (ii) (iii) (iv) (v) Which module should be imported in Statement-1. (a) pickle (b) csv (c) file (d) text Which file mode to be passed to add new record in Statement-2. (a) w+ (b) w (c) wb (d) a What should be written in Statement-3 to close the file? (a) close() (b) fwriter.close() (c) f.close() (d) csv.close() Which function to be used in Statement-4 to read the data from a csv file. (a) read() (b) readline() (c) readlines() (d) reader() The output after executing Statement-5 will be — (a) (INDIA”, “NEW DELHI”) (“CHINA”, “BEIJING”) (b) INDIA NEW DELHI CHINA BEIJING (c) INDIA, NEW DELHI CHINA, BEIJING (d) INDIA # NEW DELHI CHINA # BEIJING KENDRIYA VIDYALAYA SANGATHAN, RAIPUR REGION Term-I Examination — 2021-22 Set-2 Answer Key Class- XII, Subject - Computer Science (083) Duration: 90 mins. MM: 35 General Instructions to the Examinee: This question paper contains two parts A and B. Each part is compulsory. Both Part A and Part B have choices. Part-A is having MCQs (Attempt 27 out of 35 questions). Part- B has two questions based on Case studies. a. Each case study has 4 case-based subparts. b. An examinee is to attempt any 4 out of the 5 subparts. 5. All programming questions are to be answered using Python Language only. Pedr Part-A (Attempt any 27 questions from question no 1 to 35.) 1. What possible output(s) are expected to be displayed on screen at the time of execution of the program from the following code? from random import randint LST=[5,10,15,20,25,30,35,40,45,50,60,70] first = randint(3,8) — 1 second = randint(4,9) — 2 third = randint(6,11) — 3 print(LST[first],"#", LST[second],"#", LST[third],"#") a) 20#25#25# b) 30#40#70# c) 15#60#70# d) 35#40#60# 2. Specify the maximum values that can be assigned to each of the variables first, second and third in the code given in Question no. | - a) First: 6, Second: 6, Third: 7 b) First: 7, Second: 7, Third: 8 B c) First: 3, Second: 4, Third: 6 d) First: 8, Second: 8, Third: 9 3. Which of the following is not a valid identifier name in Python? (a) First_Name (b) _Area (c) 2nd_num Cc (d) While 4. Which statement is correct for dictionary? (a) A dictionary is an ordered set of key:value pair (b) each of the keys within a dictionary must be unique (c) each of the values in the dictionary must be unique 71|Page 20. 21. 22. 23. 24. 25. 26. 27. 28. 74|Page (d) When you open a file for writing, if the file exists, the existing file is overwritten with the new file. Which module is required to use built in function dump() Cc (a) Math (b)flush (c)pickle (d)csv Which of the following function is used to write data in binary mode? Cc (a)write (b)output (c)dump (d)send To read 2 characters from file object {1 command should be A (a)fl.read(2) (b)f 1.read() (c)flreadlineQ) (d) fl.readlines() To get byte position from the beginning of file, function used is - B (a)seek (b)tell (c)read (d)write The file pointer, used to go to particular position A (a)seek (b)tell (c)read (d)write In regards to separated value files such as .csv and .tsv, what is the delimiter? (a) Any character such as the comma (,) or tab (\t) that is used to A separate the column data. (b) Delimiters are not used in separated value files (c) Anywhere the comma (,) character is used in the file (d) Any character such as the comma (,) or tab (\t) that is used to separate the row data In separated value files such as .csv and .tsv, what does the first row in the file typically contain? D (a) The author of the table data (b) The source of the data (c) Notes about the table data (d) The column names of the data Assume you have a file object my_data which has properly opened a separated value file that uses the tab character (\t) as the delimiter. What is the proper way to open the file using the Python csv module and assign it to the variable csv_reader? Assume that csv has already been imported. (a) csv.tab_reader(my_data) (b) csv.reader(my_data) (c) csv.reader(my_data, delimiter='\t') (d) csv.reader(my_data, tab_delimited=True) When iterating over an object returned from csv.reader(), what is returned with each iteration? For example, given the following code block that assumes csv_reader is an object returned from csv.reader(), what would be printed to the console with each iteration? for item in csv_reader: print(item) B (a) The full line of the file as a string (b) The row data as a list (c) The individual value data that is separated by the delimiter (d) The column data as a list 29. 30. 31. 32. 33. 34, 75|Page Find the output of the following: >>>Line = “Fun with Python” >>> print (Name [: 5 : -1]) (a) ith Python (b) th Python (c) nohtyP ht (d) nohty What will be the Output for the following code — Language=["C", "C++", "JAVA", "Python", "VB", "BASIC", "FORTRAN"] del Language[4] Language.remove("JAV A") Language.pop(3) print(Language) (a) ['C, 'C++', 'VB', '"FORTRAN'] (b) ['C', 'C++', 'Python', 'FORTRAN'] (c) ['C, ‘C++’, BASIC’, '"FORTRAN'] (d) ['C, 'C+4', ‘Python’, 'BASIC'] An absolute path name begins at the (a) Leaf (b) Stem (c) current directory (d) root What happens if a local variable exists with the same name as the global variable you want to access? (a) Error (b) The local variable is shadowed (c) Undefined behavior (d) The global variable is shadowed Choose the correct option with reference to below Python code? def fn(a): print(a) x=90 fn(x) (a) x is the formal argument. (b) a is the actual argument. (c) fn(x) is the function signature. (d) x is the actual argument. What is the output of the following — print(21//9%3, 2**2**3) (a) 7 64 (b) 2 256 35. 36. @ (ii) (iii) (iv) 76|Page (c) 7.256 (d) 264 Assertion (A) : Keys in a Python dictionary should be unique. Reason (R) : Only immutable data types can be used as keys. (a) A is true but R is false. (b) A is false but R is true. (c) Both A and R are false. (d) Both A and R are true but R is not the correct explanation of A. (e) Both A and R are true and R is the correct explanation of A. Part-B (Attempt any 4 out of the 5 subparts in each question) In an online lottery system, names having exactly 5 characters are to be displayed. Piyush has been asked to complete this task. He has created a function FindNames() in python which read contents from a text file LOTTERY.TXT, which contains names of participants, and displays those names, which are having exactly 5 characters. He got confused with few statements and left it blank. Help him complete the code. def FindNames(): c=0 file=open((LOTTERY.TXT’, ' ‘) #Statement-1 line = file. #Statement-2 word = #Statement-3 for c in word: if : #Statement-4 print(c) #Statement-5 FindNames() Write mode of opening the file in statement-1? (a) A (b) Ab (c) W (dr Fill in the blank in statement-2 to read the data from the file. (a) File.Read() (b) file.read() (c) read.lines( ) (d) readlines( ) Fill in the blank in statement-3 to read data word by word. (a) Line.SplitO (b) Line.split() (c) line.splitO (d) split.word() Fill in the blank in statement-4, which display the word having exactly 5 characters. (a) len(c) == (b) len(c)<5 KENDRIYA VIDYALAYA SANGATHAN, RAIPUR REGION Term-I Examination — 2021-22 Model Question Paper-Set-3 Class- XII, Subject - Computer Science (083) Duration: 90 mins. MM:35 General Instructions to the Examinee: This question paper contains two parts A and B. Each part is compulsory. Both Part A and Part B have choices. Part-A is having MCQs (Attempt 27 out of 35 questions). Part- B has two questions based on Case studies. a. Each case study has 4 case-based subparts. b. An examinee is to attempt any 4 out of the 5 subparts. All programming questions are to be answered using Python Language only. ASN Part-A (Attempt any 27 questions from question no 1 to 35.) 1. Consider the following code: 1 import math import random print(str(int(math.pow(random.randint(2,4),2))),end= '') print(str(int(math.pow(random.randint(3,4),2))),end= ' ') print(str(int(math.pow(random.randint(4,4),2)))) What could be the possible outputs out of the given four choices? (a) 234 (b) 9 16 16 (c) 164 16 (d) 249 2. What is the value of x — 1 x = 23.14 + 9/2 a) 27.0 b) 27.64 c) 28 d) 27.14 3. Which type of error will occur when the following code is executed? 1 >>>print(‘Cloud’ + 9) (a) Syntax Error (b) — Type Error (c) Name Error (d) Value Error 4, Which of the following operators can be used with strings? 1 (a) / 79|Page (b) * (c) % (d) - Identify the valid declaration of data: data=(1, “One” , 2 , “Two”, 3, “Three”) (a) List (b) Tuple (c) String (d) Dictionary Which of the following functions do we use to read data in a Binary file? (a) reader( ) (b) readlines( ) (c) load() (d) read() “+? operator is used for in strings? (a) Replication (b) Duplication (c) Concatenation (d) Updation What will be the maximum and minimum value of span? >>>span = int(23 + random.random() * 8) (a) 30 and 23 (b) 31 and 23 (c) 30 and 24 (d) 31 and 24 Consider the tuple in python named NUM=(1,2,3). What will be the value of DOUBLE, if - >>> DOUBLE=NUM*2 (a) (2,4,6) (b) (1,1,2,2,3,3) (c) (1,2,3,1,2,3) (d) Error 10. t=(1,2,[3,4,5],"Confused") print(t(3][2]) Output will be — (a) 14 (b) 5 (c) n (d) 2 11. What is the use of seek() method in files? (a) sets the file’s current position at the offset (b) sets the file’s previous position at the offset (c) sets the file’s current position within the file (d) none of the mentioned 12. Find the output of the following code — fp = open("sample.txt", "r") fp.read(8) print(fp.tell() fp.close() (a) 0 80|Page (b) 7 (c) 8 (d) 9 13. Which of the following command is used to open a file “c:\newfile.txt” in read and write mode both? (a) infile = open(“c:\ newfile.txt”, “1”’) (b) infile = open(“‘c:\\ newfile. txt”, “1”) (c) infile = open(file = “c:\ newfile.txt”, “1+”) (d) infile = open(file = “c:\\ newfile.txt”, “r+’”) 14. Which of the following command is used to open a file “c:\bio.txt” in write mode only? (a) outfile = open(“‘c:\bio.txt”, “w”) (b) outfile = open(“c:\\bio.txt”, “w’”) (c) outfile = open(file = “c:\bio.txt”, “w+”) (d) outfile = open(file = “c:\\bio.txt”, “w+”) 15. Which of the following command is used to open a binary file “c:\record.dat” in append-mode? (a) outfile = open(“c:\\record.dat”, “a”) (b) outfile = open(“‘c:\\record.dat”, “ab”) (c) outfile = open(“c:\\record.dat”, “wb”) (d) outfile = open(“‘c:\\record.dat”, “w+” 16. What will be the output of the following code if content of the file “smile.txt” is— Smiling is infectious, You catch it like the flu. When someone smiled at me today, I started smiling too. file=open(“smile.txt”) contents=file.read() print(file.read(7)) (a) Smiling (b) Smilin (c) ng too. (d) No output 17. The readlines() method returns (a) A string (b) A list of words (c) A list of lines (d) A list of integers 18. In which of the following modes, the existing data of file will not be lost? (a) ab (b) w+ (c) wb (d) wb+ 19. If a file is opened for reading, which of the following statement(s) is(are) False? (a) The file must exist on the disk on the specified path. (b) If the file exists at the specified path, the file is successfully opened. 81| Page (b) 27.2 (c) 28.4 (d) 30.8 34. Find the output of the following — >>> listl=[1,2,3] >>> list2=[1,2,2,3] >>> list1>list2 (a) Error (b) False (c) True (d) None 35. Assertion (A): Parameters with default arguments can be followed by parameters with no default argument. Reason (R): Syntactically, it would be impossible for the interpreter to decide which values match which arguments if mixed modes were allowed while providing default arguments. (a) A is true but R is false. (b) A is false but R is true. (c) Both A and R are false. (d) Both A and R are true but R is not the correct explanation of A. (e) Both A and R are true and R is the correct explanation of A. Part-B (Attempt any 4 out of the 5 subparts in question no. 36 and 37) 36. Shubham Dixit of class 12 is writing a program to create a CSV file “hobby.csv” which will contain Name and hobby name for some entries. He has written the following code. As a programmer, help him to successfully execute the given task. import #Line1 def addCsvFile(Name,Hobby): # to write / add data into the CSV file f=open(‘ hobby.csv','__') # Line 2 newFileWriter = csv.writer(f) newFileWriter. writerow([Name,Hobby]) f.close() #csv file reading code def readCsvFile(): # to read data from CSV file newFile = open(' hobby.csv','r') newFileReader = csv.. (newFile) # Line 3 for row in newFileReader: print (row[0], “@”, row[1]) newFile. # Line 4 addCsvFile(“Pranav”, “Cricket”) addCsvFile(“Sunaina”, “Badminton”) addCsvFile(“Manish”, “Painting”) readCsvFile() #Line 5 84| Page @ Name the module he should import in Line 1. (a) pickle (b) csv (c) file (d) random ii) In which mode, Shubham should open the file to add data into the file.(Line 2) (a) w+ (b)r (c) r+ (d) a (iii) Fill in the blank in Line 3 to read the data from a csv file. (a) loadQ) (b) readQ) (c) reader() (d) readlineQ) (iv) Fill in the blank in Line 4 to close the file.. (a) close() (b) CloseQ) (c) CLOSEQ, (d) endQ, (vy) Write the output he will obtain while executing Line 5. (a) Pranav Cricket Sunaina Badminton Manish Painting (b) “Pranav” “Cricket” “Sunaina” “Badminton” “Manish” “Painting” (c) Pranav @ Cricket Sunaina @ Badminton Manish @ Painting (d) “Pranav” @ “Cricket” “Sunaina” @ “Badminton” “Manish” @ “Painting” 37. Subrat Ray is learning to work with Binary files in Python using a process known as Pickling/de-pickling. His teacher has given him the following incomplete code, which is creating a Binary file namely Mydata.dat and then opens, reads and displays the content of this created file. import #Statement-1 sqlist=list() for k in range(5): sqlist.append(k*k) fout=open(“mydata.dat”, #Statement-2 (sqlist,fout) #Statement-3 fout.close() fin=open(“Mydata.dat”, “rb” ) mylist= (fin) #Statement-4 fin.close() print(mylist) #Statement-5 85| Page Which module should be imported in Statement-1. (a) pickle (b) csv (c) file (d) text (ii) Which file mode to be passed to write data in file in Statement-2. (a) wt (b) ow (c) wb (d) a (iii) What should be written in Statement-3 to write data onto the file. (a) dump() (b) write() (c) pickle.dump() (d) writeline() (iv) Which function to be used in Statement-4 to read the data from the file. (a) load() (b) readline() (c) readlines() (d) pickle.load() (v) The output after executing Statement-5 will be — (a) 014916 (b) 1,4, 9, 16, 25 (c) [0, 1, 4, 9, 16] (d) [1 4, 9, 16, 25] 86|Page 12. Find the output of the following code — fp = open("sample.txt", "r") fp.read(8) print(fp.tell()) fp.close() (a) 0 (b) 7 (c) 8 (d) 9 13. Which of the following command is used to opena file “c:\newfile.txt” in read and write mode both? (a) infile = open(“c:\ newfile.txt”, “1’’) (b) infile = open(“c:\\ newfile.txt”, “1’”) (c) infile = open(file = “c:\ newfile. txt”, “1+’”) (d) infile = open(file = “c:\\ newfile.txt”, “r+”) 14. Which of the following command is used to open a file “c:\bio.txt” in write mode only? (a) outfile = open(“c:\bio.txt”, “w’”) (b) outfile = open(“c:\\bio.txt”, “w”) (c) outfile = open(file = “c:\bio.txt”, “w+”) (d) outfile = open(file = “c:\\bio.txt”, “w+”) 15. Which of the following command is used to open a binary file “c:\record.dat” in append-mode? (a) outfile = open(“c:\\record. dat”, “a”) (b) outfile = open(“c:\\record.dat”, “ab”) (c) outfile = open(“c:\\record.dat”, “wb”) (d) outfile = open(“c:\\record.dat”, “w+” 16. What will be the output of the following code if content of the file “smile.txt” is— Smiling is infectious, You catch it like the flu. When someone smiled at me today, I started smiling too. file=open(“smile.txt’”) contents=file.read() print(file.read(7)) (a) Smiling (b) Smilin (c) ng too. (d) No output 17. The readlines() method returns (a) A string (b) A list of words (c) A list of lines (d) A list of integers 18. In which of the following modes, the existing data of file will not be lost? (a) ab (b) w+ g9| Page (c) wb (d) wb+ 19. If a file is opened for reading, which of the following statement(s) is(are) False? (a) The file must exist on the disk on the specified path. (b) If the file exists at the specified path, the file is successfully opened. (c) The file, even if at a different location on disk other than the specified path, will get opened. (d) Python gives error if the file does not exist at the specified path. 20. Which of the following is not a valid mode of opening a file? (a) ab (b) rw (c) r+ (d) w+ 21. Which of the following function is used to read data in binary mode? (a)read (b)reader (c)load (d)readlines 22. Function to read all the characters of a file — (a)fl.read(n) (b)fl.readQ (c)fl.readlineQ) (d) fl.readlines() 23. To move a file pointer f, 10 bytes ahead from the current position of file, function used is - (a)f.seek(10) (b)f.seek(10,0) (c) f.seek(10,1) (d) f.seek(10,2) 24. If the content of the file “wish.txt” is — “Happy”, then what will be the content of the file after executing the following statements — fopen(“wish.txt”, ‘w’) f.write(“Birthday”) f.closeQ) (a)Happy Birthday (b)HappyBirthday (c)Happy _ (d)Birthday 25. Which of the following is not a function of csv module? (a) readline() (b) writerow() (c) reader() (d) writer() 26. Whenever possible, what is the recommended way to ensure that a file object is properly closed after usage? (a) By using try block (b) Making sure that close() function is used before end of the script (c) By using the with statement (d) It doesn’t matter 27. Which of the following is/are True? (a) When you open a file for reading, if the file does not exist, an error occurs. (b) When you open a file for writing, if the file does not exist, a new file is created. (c) When you open a file for writing, if the file exists, the existing file is overwritten with the new file. (d) All of the above 90|Page 28. Given the file image.png, which of the following is the correct way to open the file for reading as a buffered binary file? (a) open(“image.png”) (b) open(“image.png”, “r”’) (c) open(“image.png”, “rb”) (d) open(“image.png”, “wb”) 29. What is the output of the following? d= {“one”: T’, “two” : 'II’, “three” : 'III'} for iin d: print(i) (a) one two three (b) I Il mi (c) onel two II three III (d) 0 1 2 30. What is the output when following code is executed? >>>print (r"Python\tProgram") (a) Python Program (b) rPython Program (c) Error (d) Python\tProgram 31. Which of the following is the use of id() function in python? (a) id returns the identity of the object (b) Every object doesn’t have a unique id (c) All of the mentioned (d) None of the mentioned 32. What is the output of the program given below? num = 45 def func (num): num = 23 func (num) print (‘num is now', num) (a) num is now 45 (b) num is now 23 (c) num is now 68 (d) Error 91|Page (sqlist,fout) #Statement-3 fout.close() fin=open(“Mydata.dat”, “rb” ) mylist= (fin) #Statement-4 fin.close() print(mylist) #Statement-5 (i)_ | Which module should be imported in Statement-1. (a) pickle (b) csv (c) file (d) text (ii) | Which file mode to be passed to write data in file in Statement-2. (a) w+ (b) w (c) wb (d) a (iii) | What should be written in Statement-3 to write data onto the file. (a) — dump() (b) write() (c) pickle.dump() (d) writeline() (iv) | Which function to be used in Statement-4 to read the data from the file. (a) load() (b) readline() (c) readlines() (d) pickle.load() (v) | The output after executing Statement-5 will be — (a) 014916 (b) 1, 4, 9, 16, 25 (c) (0, 1, 4, 9, 16] (d) [1, 4, 9, 16, 25] 94|Page TERM-2 95|Page OTA of bilions of computers and olber eectromme devices, ’ Tnterspace is a software that allows multiple he Advanced Research ‘ : vars a client-server euivoument fg Projects Agen communicate wath each other to send and Patra (AKPANE recelve data of various types such a5 data CIRCUIT SWING (=) ea) Differences Between Circuit & Packet Switching Circuit-awitching Packet= Switching Guaranteed capacity Mo guarantees (best effort) Capacity ig wasted if data ig More efficient bursty Before sending data Send dota Immediately establishes a path All data in a single flow Different packets might follow one path follow different paths No reordering: constant © Packets tidy be reordered, delay: no pkt drops delayed, or dropped aa 97|Page AO OO RUE) BUS- Abus topology is \ f STAR~A star topology isa topology foraLoral a topology fora Local Area Network (LAN) in which all nodes are Area Network (LAN) in wich all the individually connected toa central conection anodes are connected to a single cable point, like aloub ora site, PAN-Personal Area Network TREE tree toloyise el) type of structure where many comected elements are aranged like the branches of tree LAN-Local Area Network % 101 | Page 103 | Page ua Ca Start COMPARISON BETWEEN 16, 26, 36, | aking dopants 4G AND 5G 1970) 1984 2p AMPS Analog cellular technology A) ‘aia cl wing abadbacd inet nein ited of area hw lie | Verwonl Telephone 1980/1999 1990/2002 2000/2010 2010/2015 eave [ MAOtRbps —2Mbps—200Mbps to. Gps and 1 Gbps orlow higher nil 2G:TDMA, WCDMA, Single Single CDMA,GSM CDMA2000 unified unified 256: GPRS, soda sandr EDGE,LRTT Digi cellar — Brood United Pand Unified Pand} | CDMA,IP combination combination || techaology —ofbroudband, of LANWAN/ broadband, 105 | Page Miu: (AN) audits tet pot omit viele nto _ Tt ed nei