Students must start practicing the questions from CBSE Sample Papers for Class 11 Informatics Practices with Solutions Set 8 are designed as per the revised syllabus.
CBSE Sample Papers for Class 12 Informatics Practices Set 8 with Solutions
Time Allowed: 3 hours
Maximum Marks: 70
General Instructions:
- All questions are compulsory.
- Answer the questions after carefully reading the text.
- Student has to answer only one question where choice is given.
- All programming questions have to be answered with respect to Python only.
- In Python indentation is mandatory; however, number of spaces used for indenting may vary.
- In SQL related questions – semicolon should be ignored for terminating the SQL statements.
- Use of calculators is not permitted.
SOLVED
Multiple Choice Questions:
Question 1.
(i) Which of the following is not an example of system software?
(A) Language Translator
(B) Utility Software
(C) Operating System
(D) Word Processors
Answer:
(D) Word Processors [1]
Explanation: System software is a type of computer program that is designed to run a computer’s hardware and application programs, e.g. Language Translator, Utility Software, Operating System.
(ii) You don’t have to pay for Python and you can view its source code too. It means Python is _____.
(A) Free and open source
(B) freeware
(C) open source
(D) shareware
Answer:
(A) Free and open source [1]
Explanation: Python is developed under an OSI approved open source license, making it freely usable and distributable, even for commercial use. Python’s license is administered by the Python Software Foundation.
(iii) A combination of two or more attributes that is used as a primary key are called.
(A) Alternate keys
(B) Candidate keys
(C) Composite keys
(D) None of these.
Answer:
(C) Composite keys [1]
Explanation: In certain tables, a single key cannot be used to identify rows uniquely and a combination of two or more attributes is used as a primary key. Such keys are called Composite keys.
(iv) The file that contains about data-
(A) Metadata
(B) Database
(C) Data dictionary
(D) All of these
Answer:
(C) Data dictionary [1]
Explanation: A database scheme is specified by a set of definitions which are expressed by a special language called DDL. The result of compilation of DDL statements is a set of tables which are stored in a special file called data dictionary.
(v) Which of the following provides immersive experiences to the users?
(A) Three-dimensional
(B) Video games
(C) Both (A) and (B)
(D) Natural Language Processing
Answer:
(C) Both (A) and (B) [1]
Explanation: With the three-dimensional (3D) videography, the joy of watching movies in theatres has reached to a new level. Video games are also being developed to provide immersive experiences to the player. Immersive experiences allow us to visualise, feel and react by stimulating our senses. It enhances our interaction and involvement, making them more realistic and engaging. Immersive experiences have been used in the field of training, such as driving simulators, flight simulator and so on. Immersive experience can be achieved using virtual reality and augmented reality.
Question 2.
(a) Give the name of input devices.
Answer:
(a) Keyboard, mouse, scanner, touch screen. [1]
(b) What is the function of control unit?
Answer:
The basic function of control unit is to fetch the instructions stored in the main memory, identify the operations and the devices involved in it and accordingly generate control signals. [2]
(c) Explain Random Access Memory and name its types.
Answer:
Random Access Memory (RAM) is used for temporary storage of input data, output data and intermediate results. It is also known as read/write memory as it allows CPU to read as well as write data or instructions into it. There are two types of RAM: (i) DRAM; (ii) SRAM. [2]
(d) Define application software with its types.
OR
Write about the function and parts of Central Processing Unit (CPU).
Answer:
The system software provides the core functionality of the computer system. However, different users use the computer system for different purposes depending upon their requirements. Hence, a new category of software is needed to cater to different requirements of the end users. This specific software that works on top of the system software is termed as application software.
There are two categories of application software as:
(i) General Purpose Application Software:
This software is developed for generic applications, to cater to a bigger audience in general. Such ready-made application software can be used by end users as per their requirements.
(ii) Specific Purpose Application Software:
These are custom or tailor made application software, that are developed to meet the requirements of a specific organisation or an individual. They are better suited to the needs of an individual or an organisation. For example, school management software, accounting software etc. [4]
OR
Central Processing Unit (CPU) consists of a set of registers, arithmetic logic unit and control unit, which together interprets and executes. Central Processing Unit is often called the brain of computer. The CPU is fabricated as a single Integrated Circuit (IC) and is also known as microprocessor.
The primary functions of the CPU are as follow:
- The CPU transfers instructions and input data from main memory to registers i.e internal memory.
- The CPU executes the instructions in the stored sequence.
- When necessary, CPU transfers output data from registers to main memory.
- A CPU controls all the internal and external devices to perform arithmetic and logical operations.
The CPU consists of two parts:
(i) Arithmetic Logic Unit (ALU) performs all arithmetic and logical operations for the CPU.
(ii) Control Unit (CU) controls the operations of the computer system. [4]
Question 3.
(a) How much disk space is used to download Python?
Answer:
Python needs 25 Mb disk space to download. [1]
(b) What is the extension of Python files?
Answer:
.py [1]
(c) What is dictionary?
Answer:
Dictionary in Python is an unordered collection of data values that store data values like a map.l
Commonly Made Error:
Students got confused in list and dictionary.
Answering Tip:
Dictionary includes the element in the form of key value pair in which key is uniquely identified.
(d) Find the output
a = [10,20,30,40,50,60,70]
print (a [4 :1: – 5])
Answer:
Output: [50] [1]
(e) What result will be produced after executing the following code:
list1 = [‘Delhi’, ‘Meerut’, ‘Hapur’, ‘Agra’]
list2 = list1
list3 = list1 [: ]
list2 [1] = ‘Mumbai’
list3 [3] = ‘Chandigarh’
sum = 0
for i in (listl, list2, list3) :
if i [1] == ‘Mumbai’:
sum += 5
if i [3] = ‘Chandigarh’ :
sum += 10
print (sum) [2]
OR
How can you remove key: value pair from a dictionary?
Answer:
Output 20
OR
(i) del < dictionary > [key]
(ii) < dictionary >. pop [key]
(f) Differentiate between interactive mode and script mode. [4]
Answer:
| Script mode | Interactive mode |
| Script mode is a defined set of steps that need to be followed in order for the computer to understand and carry out the instructions. | Interactive mode, on the other hand, is where the user can type in commands and see the results straight away. |
| Script mode is more suitable when there is a need to automate tasks or when the same task needs to be carried out several times. | The interactive mode is more suitable for one-time tasks or for exploring data. |
| Script mode is usually edited in a text editor and then run as a batch process. | Interactive mode can be edited in the same way as commands are typed in, which makes it more userfriendly. |
| Script mode produces output that can be saved and reused. | Interactive mode produces output that is displayed on the screen and then disappears. |
Question 4.
(a) What do you mean by data redundancy? [3]
Answer:
Data redundancy refers to the practice of keeping data in two or more places within a database or data storage system. Data redundancy ensures an organization can provide continued operations or services in the event something happens to its data – for example, in the case of data corruption or data loss. [3]
(b) Help Riya in predicting the output of the following queries: [3]
(i) SELECT (7*4+3-l) AS ‘FINAL’;
(ii) SELECT (8%2+4*2) AS ‘RESULT’;
(iii) SELECT (6*2/2+4) AS ‘PRINT’;
Answer:
(i) FINAL 30
(ii) RESULT 8
(iii) PRINT 10 [3]
(C) What is the original purpose of SQL? [3]
Answer:
(i) To specify the syntax and semantics of data definition language.
(ii) To specify the syntax and semantics of data manipulation language.
(iii) To define the data structures. [3]
(D) Give the terms for each of the following: [4]
(i) Collection of logically related records.
(ii) The skeleton structure that represents the logical view of the entire database.
(iii) Attribute that can uniquely identify the tuples in a relation.
(iv) Special value that is stored when actual data value is unknown for an attribute.
Answer:
(i) Database
(ii) Database schema
(iii) Primary key
(iv) Null [4]
Question 5.
(a) What is the main purpose of a database system? [1]
OR
Which data type is used to store the character string in SQL? [1]
Answer:
Main purpose of a database system is to provide users with an abstract view of the system. [1]
OR
CHAR(size), data type is used to store the character string. [1]
(B) Write command to create table Teacher whose fields are: [2]
| F_ID | varchar |
| Name | char |
| Salary | float |
| Address | varchar |
| Qualification | varchar |
| Experience | int |
Answer:
CREATE TABLE Teacher
(T_ID int Primary Key,
Name Char (20),
Salary Float,
Address Varchar (30),
Qualification Varchar (20)); [2]
(C) From table Teacher in Q. No. (5) (b), answer the following questions [2]
(i) Identify the primary key
(ii) Identify the alternate key
Answer:
(i) T_ID
(ii) Name 2
(d) What do you mean by attribute? [2]
Answer:
In a database management system (DBMS), an attribute refers to a data base component such as table columns. It also may refer to a database field. Attribute describe the instance in the row of database. [2]
Commonly Made Error:
Some students got confused and they wrote i advantage of attribute instead of their ! definition. i
Answering Tip:
An attributes are the describing characteristics or properties that define all items pertaining to a certain category applied to all cells of a column.
(e) What is a Relation in Database? 03 [4]
Answer:
Relation is used to refer to a table in a relational database but is more commonly used to describe the relationships that can be created between those tables in a relational database. Relations have three important properties name, cardinality and degree which are describe as : Name: The first property of a relation is its name which is represented by the title or entity identifier.
Cardinality’: It refers to the number of rows (tuples) in relation that defines the uniqueness of data value contained in a column.
Degree: It refers to the number of column (attributes) in each tuples.
(f) Give the output of following queries based on given table Item.
| I_Code | I_Name | Manufacturer | Qty | Discount | Amount |
| 101 | Pen | ABC | 50 | 10 | 1000 |
| 102 | Notebook | ABC | 250 | 10 | 2050 |
| 103 | Books | XYZ | 150 | 8 | 8500 |
| 104 | Bags | ABC | 10 | 5 | 5400 |
| 105 | Table | XYZ | 15 | 8 | 27000 |
(i) SELECT I_Name, manufacturer FROM Item WHERE I_Code=103;
(ii) SELECT Qty, Amount FROM Item WHERE Discount <8;
(iii) SELECT I_Code, I_Name, Qty FROM Item WHERE Manufacturer NOT IN (‘XYZ’)
(iv) SELECT Qty FROM Item WHERE Discount = 10;
Answer:
Question 6.
(a) Which of the following can be used as valid variable identifiers in Python?
(i) Total
(ii) > sumNum
(iii) Question
(iv) Addition 2
Answer:
(a) (i) and (iii) are valid. 2
(b) Write a Python program to input two strings and swap them.
Answer:
str1 = input(“Enter First String: “)
str2 = input(“Enter Second String: “)
print(“\nBoth String before swapping:”)
print (“First String =”,str1)
print(“Second String =”,str2)
temp = str1
str1 = str2 str2 = temp
print (“\nBoth String after swapping:”)
print(“First String =”, str1)
print(“Second String =”, str2) [3]
(c) Write a program to find the length of the string “Programming Language” without using len function. [2]
Answer:
a = “Programming Language”
count = 0
for i in a:
count = count+1
print(count) [2]
(d) Write a program to calculate the average and total of 5 numbers in a list. Also, display its output. [3]
Answer:
num = int(input(‘How many numbers: ‘) )
total = 0
for n in range(num):
numbers = float(input(‘Enter number : ‘) )
total += numbers
avg = total/num
print(“Total of 5 numbers is :”, total)
print(‘Average of ‘, num, ‘ numbers is : ‘, avg)
Question 7.
(a) Give the differences between virtual reality and augmented reality. [2]
Answer:
| Virtual Reality (VR) | Augmented Reality (AR) |
| (i) The user no longer perceives the real environment, | (i) The user still sees the real world, but receives additional information displayed |
| (ii) VR implies complete immersion experience that shuts out the physical world, | (ii) AR adds digital elements to live often by using the camera on a smartphone, |
Commonly Made Error:
Students confuse between VR and AR.
Answering Tip:
Remember VR takes us into a virtual world while AR gives us an experience of the real \ world.
(b) What is grid computing? [2]
Answer:
Grid computing is a computer network in which each computer’s resources are shared with every other computer in the system. It is a special kind of distributed computing. Grids have a variety of resources based on diverse software and hardware structures. [2]
Question 8.
Consider the following dictionary statecapital: [4]
statecapital = {“Assam”: “Guwahati”, “Bihar”: “Patna”, “Maharashtra”: “Mumbai”, “Rajasthan”: “Jaipur”}
(i) To print the capital ‘Patna’, the code should be:
(A) print (statecapital.get(“Bihar”))
(B) print(statecapital[“Bihar”])
(C) print(statecapital[2][1])
(D) both (A) and (B)
Answer:
(D) both (A) and (B)
(ii) print (statecapital.keys( )) will print:
(A) dict_keys([’Assam’, ‘Bihar’, ‘Maharashtra’, ‘Rajasthan’])
(B) dict_values([‘Guwahati’, ‘Patna’, ‘Mumbai’,’Jaipur’])
(C) Error
(D) dict_keys(l,2,3,4)
Answer:
(A) dict_keys([’Assam’, ‘Bihar’, ‘Maharashtra’, ‘Rajasthan’])
(iii) print (len (statecapital)) will print:
(A) 8
(B) 4
(C) 55
(D) 10
Answer:
(B) 4
(iv) print (“Maharashtra” in statecapital), the output will be:
(A) True
(B) False
(C) Yes
(D) No
Answer:
(A) True
(v) The output of the segment will be:
del statecapital [“Assam”]
print (statecapital)
(A) {‘Assam’: Null, ‘Bihar1: ‘Patna’, ‘Maharashtra’: ‘Mumbai’, ‘Rajasthan1: ‘Jaipur’}
(B) {Null: ‘Guwahati’, ‘Bihar1: ‘Patna’, ‘Maharashtra’: ‘Mumbai’, ‘Rajasthan’: ‘Jaipur’}
(C) {‘Bihar’: ‘Patna’, ‘Maharashtra1: ‘Mumbai’, ‘Rajasthan’: ‘Jaipur’}
(D) Syntax error
Answer:
(C) {‘Bihar’: ‘Patna’, ‘Maharashtra1: ‘Mumbai’, ‘Rajasthan’: ‘Jaipur’}