Students must start practicing the questions from CBSE Sample Papers for Class 11 Informatics Practices with Solutions Set 6 are designed as per the revised syllabus.
CBSE Sample Papers for Class 12 Informatics Practices Set 6 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 Question:
Question 1.
(i) acts as a supervisor by controlling and guiding the operations taking place. [1]
(A) Arithmetic logic unit
(B) Control unit
(C) Memory unit
(D) None of these
Answer:
(B) Control unit
Explanation: A control unit (CU) handles all processor control signals. It directs all input and output flow, fetches code for instructions from micro programs and directs other units and models by providing control and timing signals.
(ii) Which of the following is the correct extension of the Python file? [1]
(A) .python
(B) .pi
(C) .py
(D) .p
Answer:
(C) .py
Explanation: ‘.py’ is the correct extension of the Python file. Python programs can be written in any text editor. To save these programs we need to save in files with file extension ‘.py’.
(iii) The full form DML is- [1]
(A) Database Manipulation Language
(B) Data Maintaining Language
(C) Data Manipulation Language
(D) Database Maintaining Language
Answer:
(C) Data Manipulation Language
Explanation: After the database has been created, the data can be manipulated using a set of procedures which are expressed by a special language called Data Manipulation language.
(iv) The attribute of the table is related to: [1]
(A) Row of the table
(B) Column of the table
(C) Name of the table
(D) None of these
Answer:
(B) Column of the table
Explanation: Each column of a table represents some attribute of the entity.
(v) The superimposition of computer generated perceptual information over the existing physical surroundings is called as ______. [1]
(A) Immersive Experiences
(B) Virtual Reality
(C) Augmented Reality.
(D) Machine Learning.
Answer:
(C) Augmented Reality.
Explanation: The superimposition of computer generated perceptual information over the existing physical surroundings is called as Augmented Reality (AR). It adds components of the digital world to the physical world, along with the associated tactile and other sensory requirements, thereby making the environment interactive and digitally manipulable.
Question 2.
(a) Define the register. [1]
Answer:
Registers are used to quickly accept, store and transfer data and instructions that are being used immediately by the CPU.
(b) What is the function of ALU? [2]
Answer:
The ALU performs all the four arithmetic (+, -, *, f) and some logical (<, >, =,<=,> =) operations.
For this, the operands are sent from memory to ALU where the desired operation takes place and the result is returned to the memory. The logical operator provides the capability of decision making in the computer. [2]
(c) What are the major causes of data loss? [2]
Answer:
Most data loss is caused by human error like, if someone sent data to the wrong person, some other causes are—power outages, natural disasters, equipment failures or malfunctions, accidental deletion of data, unintentionally formatting a hard drive, damaged hard drive, read write heads, software crashes, logical errors and some physical damage to hard drives or thefts. [2]
Commonly Made Error:
Mostly students consider hard disk corruption as the only cause of data loss.
Answering Tip:
Data loss is most of the times accidental but ! i sometimes it may be intentional too.
(d) Explain the Read Only Memory (ROM) and its type ? [4]
OR
Define data representation on following terms.
(i) Magnetic media
(ii) Optical media [4]
Answer:
Read Only Memory (ROM) does not lose its contents when the power is switched off. ROM is also known as non-volatile or permanent storage. ROM can have data and instructions written to it only one time. Once a ROM chip is programmed at the time of manufacturing it cannot be reprogrammed or rewritten. Three categories of ROM are as follow:
(i) Programmable ROM (PROM) : It is also nonvolatile in nature once a PROM has been programmed, its content can never be changed. It is one time programmable device. These types of memories are found in video game consoles, mobile phones, implantable medical devices and high definition multimedia interface.
(ii) Erasable Programmable ROM (EPROM) : It is similar to PROM, but it can be eased by exposure to strong ultraviolet light. It is also known as Ultraviolet Erasable Programmable ROM (UVEPROM).
(iii) Electrically Erasable Programmable ROM (EEPROM): It is similar to EPROM, but it can be erased electrically then re-written electrically and the burning process is reversible by exposure to electric pulses. It is the most flexible type of ROM and is now commonly used for holding BIOS. [4]
OR
(i) Data Representation on magnetic media:
In magnetic media, the laser beam reflected from the land is interpreted, as 1. The presence of a magnetic field in one direction on magnetic media is represented by 1 while the field in the opposite direction is represented by 0.
(ii) Data representation on optical media:
In optical devices, the presence of light is represented by 1 while the absence of light is represented by 0. This technology is used by optical devices to read or store data. [4]
Question 3.
(a) How to access the interactive mode in Python ? [1]
Answer:
Start button → All Programs → Python → IDLE (Python) [1]
(b) Write the output of the following code
a, b = 4,8
a, b = b, 4*2
print (a, b) [1]
Answer:
8,8 [1]
(c) Write the mathematical equation in Python for expression-
x = 4x3 + 3 x + 7
Answer:
x = 4*(x**3) + 3*x + 7 [1]
(d) What is the difference between objects stored in list and dictionary? [1]
Answer:
Objects stored in list are ordered while those in dictionaries are unordered. [1]
(e) What does in operator do?
print (arr [i], pop ( )) [2]
Answer:
in is a membership operator. It evaluates to True if it finds a variable/string in the specified sequence otherwise it evaluates to False,
e.g. >>> stu = {‘Name’: ‘Washim’,’Age’: 15}
> > > ‘Age’ in stu
True [2]
OR
Output
7
15
23
31
2
(f) Write a program to find the union of two lists which are entered by user. [*p] [4]
Answer:
list1 = [ ]
n1 = int (input(“Enter size of list1 :”) )
for i in range (n1) :
num1 = int (input (“Enter any number”))
list1. append (num1).
list2 = [ ]
n2 = int (input(“Enter size of list2 :”) )
for j in range (n2) :
num2 = int (input (“Enter any number”))
list2. append (num2)
union = list (set ( ) . union (list 1, list2))
print (“\n The Union of two lists is\t”, union) [4]
Commonly Made Error:
Few students forget to use colons at their proper place.
Answering Tip:
Colon must be used after conditional statements as for, while, if etc.
Question 4.
(a) State the difference between DDL and DML. [3]
Answer:
| DDL (Data Definition Language) | DML (Data Manipulation Language) |
| It is used to create database schema and can be used to define some constraints as well. | It is used to add, retrieve or update the data. |
| It basically defines the column (Attributes) of the table. | It adds or updates the row of the table. These rows are called as tuple. |
| It doesn’t have any further classification Procedural | It is further classified into Procedural and Non DML. |
(b) What are the limitations of file system that can be overcome by a relational DBMS? [3]
Answer:
There are various limitations of file system that can be overcome by a relational DBMS as:
- Data redundancy and inconsistency
- Difficulty in accessing data
- Integrity problem
- Atomicity problem
- Concurrent access anomalies
- Security problems
- Data isolation [3]
(c) Choose appropriate answer with respect to the following code snippet. [3]
CREATE TABLE student (
name CHAR(30),
student_id INT,
gender CHAR(1),
PRIMARY KEY (student_id));
(i) What will be the degree of student table?
(ii) What does ‘name’ represent in the above code snippet ?
(iii) What does the following SQL statement do?
SELECT * FROM student;
Answer:
(i) 3
(ii) Column
(iii) Displays column names and contents of table ‘student’ [3]
(d) Explain SQL in detail. [4]
Answer:
SQL (Structured Query Language) is a set of commands that is recognised by nearly all RDBMS.
(i) SQL is a comprehensive database language, it has statements for data definition, query and update. Hence, it is both DDL and DML.
(ii) SQL consists of commands; each command has an operational part and a condition part. Operation is executed through a search in all relations defined in relational database.
(iii) Required solution (list of data) is returned by the command. The data listed in solution satisfies all conditions given in that command.
(iv) In addition, it has facilities for defining views on the database for specifying security and authorization, for defining integrity constraints and for specifying transaction controls. It also has rules for embedding SQL statements into a general purpose programming language such as C or Pascal. [4]
Question 5.
(a) Which property of a relation is used to represent number of columns? [1]
OR
Write the syntax to insert rows in a table.
Answer:
(a) Degree. [1]
Commonly Made Error:
Some students got confused in degree and cardinality.
Answering Tip:
Degree is attributes in each tuple, while cardinality is tuple in table.
OR
INSERT INTO Table_name (Columnl, CoIumn2,columnN)
VALUES (data_valuel, data_value2, data-value N); [1]
(b) Explain relational model. [2]
Answer:
The relational model represents the database as a collection of relations. A relation is nothing but a table of values. Every row in the table represents a collection of related data values. These rows in the table denote a real world entity or relationship. [2]
(c) Write command to create table Faculty whose fields are- [2]
| F_ID | varchar |
| Name | char |
| Salary | float |
| Address | varchar |
| Qualification | varchar |
| Experience | int |
Answer:
CREATE TABLE Faculty (F_ID Varchar(5) Primary Key,
Name Char (20),
Salary Float,
Address Varchar (30),
Qualification Varchar (20),
Experience int); [2]
(d) From table Faculty in Q. No. (5) (c), answer the following questions- [2]
(i) Identify the primary key
(ii) Identify the alternate key
Answer:
(i) F_ID
(ii) Name [2]
(e) Write SQL command for the following in the basis of given table STUDENT: [4]
| No. | Name | Stipend | Stream | AvgMark | Grade | Class |
| 1 | Karan | 400.00 | Medical | 78.5 | B | B |
| 2 | Diwakar | 450.00 | Commerce | 89.2 | A | C |
| 3 | Divya | 300.00 | Commerce | 68.6 | C | C |
| 4 | Arun | 350.00 | Humanities | 73.1 | B | C |
| 5 | Sabina | 500.00 | Nonmedical | 90.6 | A | A |
| 6 | John | 400.00 | Medical | 75.4 | B | B |
| 7 | Robert | 250.00 | Humanities | 64.4 | C | A |
| 8 | Rubina | 450.00 | Nonmedical | 88.5 | A | A |
| 9 | Vikas | 500.00 | Nonmedical | 92.0 | A | A |
| 10 | Mohan | 400.00 | Commerce | 67.5 | C | C |
(i) Select all the nonmedical stream students from STUDENT
(ii) List the name of those students who are in class 12 sorted by Stipend.
(iii) List al student sorted by Average Mark in descending order.
(iv) Display all record of the table STUDENT.
Answer:
(i) SELECT * FROM STUDENT WHERE STREAM =”Nonmedical’;
(ii) SELECT NAME FROM STUDENT WHERE CLASS LIKE “12%” ORDER BY STIPEND;
(iii) SELECT * FROM STUDENT ORDER BY AVGMARKS DESC;
(iv) SELECT * FROM STUDENT; [4]
(f) What are the results of setting referential integrity? [4]
Answer:
When referential integrity is enforced
(i) A value that doesn’t exist in the primary key of the primary table can’t be entered in to the foreign key field of a selected table.
(ii) A record in primary table can’t be deleted if a matching record exits in a related table.
(iii) The primary key value of a record in primary table can’t be updated if a related table has a matching record. [4]
Question 6.
(a) Which of the following can be used as invalid variable identifiers in Python?
(i) 4th Sum
(ii) Total
(iii) Numbers 2
(iv)_Data
Answer:
(a) (i) and (iii) are invalid identifiers. [2]
(b) What are literals? Name the types of literals.
Answer:
Literals are those data terms whose values cannot be changed during program execution. Several kinds of literals in Python are:
- String literals
- Numeric literals
- Boolean literals
- Special literal None
- Literal collection [3]
(c) Write a program to find the sum of all elements in a list.
Answer:
list = [ ]
number = int (input(‘How many number:’ ) )
for i in range (number) : num = int (input(‘Enter number’)) list, append (num) for i in range (0, number) : sum + = num [i]
print (“Sum of elements in giver, list is sum) [3]
(d) Predict the output
print (10<20 and 10) print (10>20 or 20)
print (10<(10 or (20)) print (10>20 not 20)
Answer:
Output 10
20
False
True [2]
Question 7.
(a) Define natural language processing (NLP).
Answer:
(i) NLP is a branch of artificial intelligence that deals with the interaction between computers and humans using the natural language.
(ii) Natural language processing represents the automatic handling of natural human language like speech or text and although the concept itself is fascinating, the real value behind this technology comes from the use cases. [2]
(b) What is immersive experience?
Answer:
(i) 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,
(ii) An immersive experience is the perception of being in one place when you are actually in another. It is essentially the suspension of reality, even if just for a few moments. [2]
Case Based Questions [Attempt any 4]
Question 8.
Dictionary is a data type in Python which stores the data in key value pair. Each key value pair is separated by comma. While each key with its corresponding value is given by colon (:), key value pairs are shown in curly brackets in dictionaries. Keys of a dictionary are immutable. [4]
student = {“Name”: “Rakhi”, “Class”: 11, “Subject”: “Mathematics”, “RollNo”: 27}
(i) The output of student[“Mathematics”] will be:
(A) ‘Subject’
(B) Key Error
(C) None of these
(D) Key not found
Answer:
(B) Key Error
(ii) student[“Class”] =12 will:
(A) update the student class
(B) generate the error
(C) add a new element to the dictionary
(D) None of these
Answer:
(A) update the student class
(iii) student[“City”]= Lucknow will:
(A) add a new element into the dictionary
(B) equal to (=) operator is not used to add the element
(C) generate error (Lucknow is not defined)
(D) None of these
Answer:
(C) generate error (Lucknow is not defined)
(iv) student[90]= “Marks” will:
(A) add a new element as (90: ‘Marks’)
(B) generate error (90 cannot be key)
(C) equal to (=) operator is not used to add the element
(D) None of these
Answer:
(A) add a new element as (90: ‘Marks’)
(v) The length of dictionary student after executing Q 3. and Q4. will be:
(A) 8
(B) 4
(C) 5
(D) 10
Answer:
(C) 5